AR-V7 Identifies Patients Unlikely to Respond to Common Therapy for Advanced Prostate Cancer

Prostate cancer is driven by male hormones (otherwise known as androgens) like testosterone. In men with advanced prostate cancer, androgen deprivation therapy (ADT), or therapies that block androgens from acting on prostate cancer cells, can slow or stop the progression of the cancer. Unfortunately, prostate cancer cells will eventually survive and grow despite standard, first-line ADT – a state called castration-resistant prostate cancer (CRPC). For these men, treatments that further suppress the generation of androgens or block the androgen receptor are the next step. Abiraterone is a medication that inhibits important enzymes in the synthesis of androgens and enzalutamide blocks androgens from acting on the receptor on prostate cancer cells. These medications extend the lives of approximately 80% of the men who take them, however 20% will have little or no response.

Researchers at Johns Hopkins' Kimmel Cancer Center and Brady Urological Institute may have discovered why. These findings were published in the most recent version of the NEJM (New England Journal of Medicine) and demonstrate that prostate cancer patients whose tumors contain a shortened receptor called AR-V7 are less likely to respond to abiraterone or enzalutamide. AR-V7 is a shortened form of the androgen receptor that lacks a binding spot targeted by enzalutamide and abiraterone. With no binding spot for the two drugs, AR-V7 is free to manipulate prostate cancer cells' genetic material, which makes the cancer cells grow and spread. A total of 62 patients, 31 patients taking each medication, were studied by looking for AR-V7 in circulating tumor cells (CTCs) from blood samples.

Waterfall Plots of Best Prostate-Specific
Antigen (PSA) Responses According to
AR-V7 Status.  From NEJM.

Of the 31 patients taking enzalutamide:

• 39% were AR-V7-positive, and in these patients:
  • None (0%) had a PSA reduction, compared to 53% of patients who were AR-V7-negative (P=0.004)
  • PSA-progression-free survival was shorter (1.4 months vs. 6.0 months, P<0.001)
  • Survival was shorter (5.5 months vs. not reached, P=0.002)

Of the 31 patients taking abiraterone:

• 19% were AR-V7-positive, and in these patients:
  • None (0%) had a PSA reduction, compared to 68% of patients who were AR-V7-negative (P=0.004)
  • PSA-progression-free survival was shorter (1.3 months vs. not reached, P<0.001)
  • Survival was shorter (10.6 months vs. not reached, P=0.006)

Jun Luo, PhD

"In this study, we've connected AR-V7 detection with resistance to two popular drugs for prostate cancer, and we've done it in a non-invasive way," says Jun Luo, Ph.D., Associate Professor of Urology at the Brady Urological Institute at Johns Hopkins first identified AR-V7 in 2007. "We hope this study will motivate scientists and clinicians to conduct additional studies on AR-V7 and to develop effective therapies to overcome resistance."

"Until now, we haven't been able to predict which patients will not respond to these therapies. If our results are confirmed by other researchers, a simple blood test could use AR-V7 as a biomarker to predict enzalutamide and abiraterone resistance, and let us direct patients who test positive for AR-V7 toward other types of therapy sooner, saving time and money while avoiding futile therapy," says Emmanuel Antonarakis, M.D., Assistant Professor of Oncology at Johns Hopkins and lead author on the study.

Emmanuel Antonarakis, MBBCh

"Patients whose blood samples contained AR-V7 got no benefit from either enzalutamide or abiraterone," says Antonarakis. He adds that AR-V7 could appear in patients' blood samples at the very start of therapy or acquired later, after therapy has begun. He says, "This test could be used before starting enzalutamide or abiraterone therapy, and if the test shows the presence of AR-V7, patients may opt for a different therapy. It could also be used to monitor patients during the course of therapy with enzalutamide or abiraterone for AR-V7, providing an indication these drugs may not work for much longer."

Take-home: If large-scale studies validate the findings, the investigators say men with detectable blood levels of AR-V7 should avoid these two drugs and instead take other medicines (such as chemotherapy, perhaps) to treat their prostate cancer.

To read the entire article follow this link to the New England Journal of Medicine (NEJM).

Antonarakis ES, Lu C, Wang H, Luber B, Nakazawa M, Roeser JC, Chen Y, Mohammad TA, Chen Y, Fedor HL, Lotan TL, Zheng Q, De Marzo AM, Isaacs JT, Isaacs WB, Nadal R, Paller CJ, Denmeade SR, Carducci MA, Eisenberger MA, Luo J.  AR-V7 and Resistance to Enzalutamide and Abiraterone in Prostate Cancer.  N Engl J Med. 2014 Sep 3. DOI: 10.1056/NEJMoa1315815

The study was funded by the Prostate Cancer Foundation, the Department of Defense, and the National Institutes of Health's National Cancer Institute (CA058236, CA006973).

Source of Quotations: "Blood test for 'nicked' protein predicts prostate cancer treatment response" at http://www.eurekalert.org/pub_releases/2014-09/jhm-btf_1090214.php

Journal Spotlight: How to Treat Non-Invasive Bladder Cancer

Approximately 60k new patients are diagnosed with bladder each year in the United States.[1]  Most of those cancers (upwards of 70-80%) are non-muscle invasive urothelial cancers of the bladder (NMIUC) - meaning these are cancers that arise from the lining of the bladder and grow outward into the lumen of the bladder.[2,3] Fortunately, most of these cancers are not inherently dangerous and can be safely managed with close surveillance and a variety of interventions.  However, NMIUC represent a wide variety of tumor types and has a wide range of prognoses and therapeutic options.  Most NMIUC are treated with a combination of surgical resection (or transurethral resection of bladder tumor, TURBT) and intravesical treatment (BCG is the most common).

The American Urological Association and other groups have attempted to stratify NMIUC patients based on their risk of recurrence, progression to muscle-invasive disease and effective treatment options.  Low- and high-risk groups are well agreed upon by a number of professional urologic and oncologic organizations. However, the risk of progression and treatment options are not well flushed out in the intermediate-risk group.  A recent publication by the International Bladder Cancer Group (IBCG), in the Journal of Urology, creates a framework for intermediate-risk patients.[4]

This blog will put this manuscript in a Journal Spotlight and review the suggested definitions and treatments for patients with low-, intermediate- and high-risk NMIUC.  For more details regarding the methodology and evidence behind these conclusions, you can access the manuscript by clicking on the subsequent link:

Kamat AM, Witjes JA, Brausi M, Soloway M, Lamm D, Persad R, Buckley R, Böhle A, Colombel M, Palou J.  Defining and Treating the Spectrum of Intermediate Risk Nonmuscle Invasive Bladder Cancer.  J Urol. 2014 Aug;192(2):305-315. Review.

Non-muscle Invasive Urothelial Cancers of the Bladder (NMIUC)

Low-Risk 

Definition: Solitary, primary low-grade papillary Ta tumor
Well-agreed upon definition
Treatment Options:
Transurethral Resection of Bladder Tumor (TURBT)
Single, immediate post-operative chemotherapy (mitomycin C) - [Evidence: 5,6]
Office Fulguration
Active surveillance with serial cystoscopy
Cancer Outcomes:
Recurrence: 50-70%
Progression:  5-10%
Deaths: 1-5%

Intermediate-Risk 

Definition: Multiple or recurrent low-grade Ta tumors***

The following risk factors stratify intermediate-risk patients:

• Multiple tumors
• Tumor size >3cm
• Early recurrence (<1 year)
• Frequent recurrences (>1 per year)

Those patients with no risk factors should be considered as Low-Risk NMIUC (see above).

Those patients with 1-2 risk factors should be considered as Intermediate-Risk NMIUC.

Those patients with 3 or more risk factors should be considered High-Risk NMIUC (see below).

***Not well-agreed upon definition (recently proposed by the IBCG)

Treatment Options:
Transurethral Resection of Bladder Tumor (TURBT)
Adjuvant intravesical treatment (BCG with maintenance for at least 1 year > chemotherapy)
     If recurrence while receiving chemotherapy, consider BCG induction and maintenance
     If recurrence while receiving BCG, consider maintenance therapy or alternative chemotherapy
Cancer Outcomes: [3,7]
Recurrence: 78%
Progression:  17%
Deaths: 10-25%

Evidence: A number of well-organized studies and meta-analyses demonstrate improvement in recurrence rates and other oncologic parameters for patients with intermediate-risk NMIUC receiving intravesical treatments.  BCG is superior to chemotherapeutic agents (epirubicin, mitomycin c) with regard to recurrence in nearly all studies, however progression and survival rates are often indeterminate.  Some of the important studies are highlighted:

• Meta-analysis: reduced recurrence rates for BCG maintenance > mitomycin C, no difference in progression or death between groups. [8]
• EORTC30911: Time to recurrence, time to distant metastases, disease-specific and overall survival improved with BCG > Epirubicin.[9]
• FinnBladder I: reduced recurrence rate with BCG maintenance > mitomycin C; trend toward decreased progression and death rates with BCG.[10]
• EORTC30962: full-dose BCG for 1 year associated with the best outcomes [11]

High-Risk 

Definition: Any T1 or high-grade tumor, and/or carcinoma in situ
Well-agreed upon definition
Treatment Options:
Transurethral Resection of Bladder Tumor (TURBT)
BCG maintenance
Consider early cystectomy
Cancer Outcomes:
Recurrence: >80%
Progression:  50% within 3 years
Deaths: 33%


While this journal article highlights a deficiency in our understanding of bladder cancer and offers a framework to better classify and treat patients, it should be clearly stated that this is not standard of care nor is it an endorsement from the Brady Urological Institute. This is merely a blog where we share important work from other contributors in the field.



[1] American Cancer Society. Cancer Facts & Figures 2014. Atlanta: American Cancer Society; 2014.
[2] Heney NM, Ahmed S, Flanagan MJ, Frable W, Corder MP, Hafermann MD et al: Superficial bladder cancer: progression and recurrence. J Urol 1983; 130: 1083.
[3] Jones SJ and Larchian WA.  Non–Muscle-Invasive Bladder Cancer (Ta, T1, and CIS). In: Campbell-Walsh Urology, 10th ed. Edited by AJ Wein, LR Kavoussi, AC Novick, AW Partin, CA Peters. Philadelphia: W. B. Saunders 2012; chapt 81, pp 2335-54.
[4] Kamat AM, Witjes JA, Brausi M, Soloway M, Lamm D, Persad R, Buckley R, Böhle A, Colombel M, Palou J.  Defining and Treating the Spectrum of Intermediate Risk Nonmuscle Invasive Bladder Cancer.  J Urol. 2014 Aug;192(2):305-315. doi: 10.1016/j.juro.2014.02.2573. Epub 2014 Mar 25. Review.
[5] Gudjónsson, S., Adell, L., Merdasa, F. et al. Should all patients with non-muscle-invasive bladder cancer receive early intravesical chemotherapy after transurethral resection? The results of a prospective randomised multicentre study. Eur Urol. 2009; 55: 773
[6] Dobruch, J. and Herr, H. Should all patients receive single chemotherapeutic agent instillation after bladder tumour resection?. BJU Int. 2009; 104: 170
[7] Sylvester, R.J., van der Meijden, A.P., Oosterlinck, W. et al. Predicting recurrence and progression in individual patients with stage Ta T1 bladder cancer using EORTC risk tables: a combined analysis of 2596 patients from seven EORTC trials. Eur Urol. 2006; 49: 466
[8] Malmström, P.U., Sylvester, R.J., Crawford, D.E. et al. An individual patient data meta-analysis of the long-term outcome of randomised studies comparing intravesical mitomycin C versus bacillus Calmette-Guérin for non-muscle-invasive bladder cancer. Eur Urol. 2009; 56: 247
[9] Sylvester, R.J., Brausi, M.A., Kirkels, W.J. et al. Long-term efficacy results of EORTC Genito-Urinary Group randomized phase 3 study 30911 comparing intravesical instillations of epirubicin, bacillus Calmette-Guérin and bacillus Calmette-Guérin plus isoniazid in patients with intermediate- and high-risk stage Ta T1 urothelial carcinoma of the bladder. Eur Urol. 2010; 57: 766
[10] Jӓrvinen, R., Kaasinen, E., Sankila, A. et al. Long-term efficacy of maintenance bacillus Calmette-Guérin versus maintenance mitomycin C instillation therapy in frequently recurrent TaT1 tumours without carcinoma in situ: a subgroup analysis of the prospective, randomised FinnBladder I study with a 20-year follow-up. Eur Urol. 2009; 56: 260
[11] Oddens, J., Brausi, M., Sylvester, R. et al. Final results of an EORTC-GU Cancer Group randomized study of maintenance bacillus Calmette-Guérin in intermediate- and high-risk Ta, T1 papillary carcinoma of the urinary bladder: one-third dose versus full dose and 1 year versus 3 years of maintenance. Eur Urol. 2013; 63: 462

Systemic Treatment of Renal Cell Carcinoma: Programmed Death Ligand 1 Inhibitors

Greater than 80% of renal tumors are renal cell carcinoma (RCC), of which about 70% is of clear-cell pathology.[1]   There are about 64,000 new RCC cases and 14,000 deaths from RCC each year, but due to increased imaging it is thought that we are catching these cancers at an earlier stage, when they are still resectable.  Unfortunately, mortality rates have not decreased and the burden of metastatic disease persists.[2]  Twenty to thirty percent of patients present with metastatic cancer and 20-30% of patients who have resectable disease later return with systemic disease following surgical management, whether it be partial or radical nephrectomy.[3,4] This underscores the necessity of management options outside of surgery.

RCC has largely been termed “chemoresistant,” meaning response to existing cytotoxic chemotherapeutic agents has been limited.  Therefore, cancer doctors and researchers continue to search for different forms of systemic treatments.[5]  In the early 1990s, immunotherapy was successfully used as systemic treatment for RCC.  The idea for this treatment came from the wide range in prognoses among patients with seemingly similar disease burden -- for example, among patients with similarly sized tumors (whether small or large), some were cured with surgery alone while patients with very similar tumors developed metastatic cancer and died.  In addition, a significant proportion of patients would have spontaneous regression of metastatic disease once the primary tumor was surgically removed.  Both of these observations suggest an interaction between the immune system and disease.[6,7] Ultimately, immunotherapies (like IFN-alpha and IL-2) were found to be more effective than previously attempted chemotherapies.  More recently, targeted therapies were developed to interrupt specific portions of the cell-cycle and endothelial attachment processes in clear-cell RCC.[8]

The idea of targeted therapy and theories of the immunoresponsive nature of clear cell RCC were combined to focus on specific parts of the immune interaction.   Among others, one important interaction is the Programmed Death Ligand 1 (PD-L1) interaction between the tumor cells and the immune cells.  T-cells are immune cells that target “foreign” cells in the body and trigger an immune response to kill those cells.  T-cells have receptors that have evolved (through genetic mutations and recombinations) to be specific for different surface proteins that may found in the cells of the body.  In a normal, healthy person, T-cells will even recognize normal, healthy cells.  However there are mechanisms to prevent the T-cell from killing good cells – a process called “anergy” which leads to T-cell death (or apoptosis).  One such signaling pathway is the PD-L1 on the healthy cell interacts with the receptor on the healthy cell (Figure 1).

Figure 1. T-Cell Recognizing Healthy Cell via PD-1-PD-L1 Interaction and Inducing Cell Death (Apoptosis).

If the T-cell identifies a tumor cell, it will not get the normal signal that it is a healthy cell, the T-cell can initiate processes to kill the tumor cell (Figure 2).

Figure 2. T-Cell Recognizing Tumor Cell without PD-1-PD-L1 Interaction.

However, some cancers like kidney cancer, can “trick” the T-cell into thinking the tumor cell is a normal, healthy cell.  One mechanism these cancers use is to express PD-L1, allowing tumor cell to escape the immune system and proliferate (Figure 3).[9]

Figure 3. Tumor Cell Expressing PD-L1 and Avoiding Detection by Immune System.

It has been noted that patients with tumors that have high expression of PD-L1 have a worse prognosis, which further suggests its involvement in the lifecycle of the disease -- although there is significant heterogeneity in expression of PD-L1 within individuals.[10]    Drugs have been developed that target both the PD-L1 on the tumor cells and the PD-1 receptor on the T-cells.  Nivolumab is the drug furthest along in the drug approval process that targets PD-1 on the T-cell.  There have been significant responses to this agent among about 30% patients who had failed treatment with the targeted therapies and enrolled in the trials. Interestingly, responses were only seen in patients who had clear-cell RCC that expressed PD-L1.[11] This response in patients who had failed the first-line targeted therapy shows promise for these novel agents. The heterogeneity of expression suggests it could play a future role in multimodal therapy.

This blog was written by Jason Cohen, Medical Student at Johns Hopkins Medical School.  Jason recently finished a four-week sub-internship at the Brady Urological Institute and gave a presentation to the department on "Programmed Death Ligand 1 Inhibitors: Systemic Treatment of Renal Cell Carcinoma" from which this blog is inspired. Jason is looking forward to a career in urology.






[1]  Siegel R et al. CA Cancer J Clin 2014; 64:9.
[2]  Hollingsworth et al. J Natl Cancer Inst. 2006; 98:1331
[3]  Curti B et al. J Am Med Assoc 2004; 292: 97
[4]  Levi D et al. J Urol 1998; 159: 1163
[5]  Chung EK et al. Am J Clin Oncol 2011; 34: 150
[6]  Oliver RT et al. Br J Urol 1989; 63: 128
[7]  Vogelzang NJ et al. J Urol 1992; 148: 1247
[8]  Rini BI et al. Lancet 2009; 373: 1119
[9]  Dong H et al. Nat Med 2002; 8: 793
[10]  Thompson RH et al. PNAS 2004; 101: 17174
[11]  Topalian SL et al. N Engl J Med 2012; 366: 2443

Neoadjuvant Chemotherapy for Bladder Cancer: What Does It All Mean?

Patients diagnosed with muscle-invasive bladder cancer can and should look to their physicians for guidance in selecting the best treatment plan for them.  In the ideal setting, a strong patient-physician relationship will facilitate the asking and answering of the many questions that come along with a new diagnosis of bladder cancer.  The majority of these questions, however, will inevitably center around the most crucial of all:

What do we do next?

In today’s world there exist many reasonable options for cancer therapy, ranging from surgery to chemotherapy to radiation.  While it may sometimes hold true that variety is the spice of life, for a patient encountering bladder cancer for the first time – forced to investigate a world which had never even previously existed to them – these options can quickly become more overwhelming than reassuring.  Therefore, today’s blog entry aims to address one of the most prevalent questions facing patients considering surgery: the role of neoadjuvant chemotherapy (or chemotherapy prior to surgery).


Historically, in patients eligible for surgery, the use of chemotherapy was considered only after surgery had been performed.  The rationale for this is no less intuitive than it seems – if you can remove a cancer, you remove it…now!  And while this dogma still frequently holds true, surgical and medical oncologists have learned over the past several years that sometimes it is best to delay surgery for a short period to allow for treatment with chemotherapy first.  Such treatment occurring prior to surgery is called “neo-adjuvant” therapy, while the more traditional “adjuvant” therapy refers to additional treatment after surgery.

In recent years, large collaborative associations both in the United States and abroad have recommended the use of neo-adjuvant chemotherapy (NAC) in treatment of muscle-invasive bladder cancer.  You may find yourself asking, though, why would a patient need chemotherapy before surgery if the cancer can be removed with surgery anyway?  On what grounds were these recommendations based?  What are the pros and cons of using neoadjuvant chemotherapy?  Finally, and perhaps most importantly, are these recommendations right for me?  In this month’s Journal of Urology, Dr. Hugh Lavery and colleagues closely examined the best-available data on the topic and set out to answer these and other questions surrounding the use of NAC in the setting of muscle-invasive bladder cancer.[1]

Why would a patient need chemotherapy before surgery if the cancer can be removed with surgery alone?

As Dr. Lavery and colleagues describe, the overall cure rate for bladder cancer after radical surgery (i.e. surgery to remove a cancerous organ along with its blood supply and adjacent tissues, such as lymph nodes) is substantially lower than that of other cancers we treat.  The reasons for this are not entirely clear, and it has led urologists to investigate what else can be done to increase the number of patients who are cured of bladder cancer with treatment.  One patient group that helps to understand the need for multiple treatment approaches, or “multimodal therapy,” is that which underwent radical cystectomy (i.e. removal of the bladder) but were then found to have no evidence of cancer remaining in the bladder at all (i.e. pathological T-stage zero, or pT0 for short).  This can be achieved if either 1) the entire tumor was removed during local excision of the mass, or 2) the cancer in the bladder was treated completely using NAC.

From following patients with pT0 disease, we have learned that even when there is no cancer left in a bladder that was removed, not all of these patients are cured in the long term.  This tells us that in some cases, a number of cancer cells too few to be seen on imaging had left the bladder and traveled elsewhere in the body.  While we believe surgery provides the best chance of curing any cancer in and around the bladder, it is no match for cells that have traveled elsewhere.  Thus, we look to systemic (i.e. entire body) treatments such as chemotherapy to assist in eradicating cancer from the body completely.

On what grounds are recommendations supporting NAC based?

Just like a contested case in court, the jury must ultimately look back to the evidence for guidance.  In the case of NAC, the evidence stems from four large randomized-controlled trials (RCTs) which compare patients who received NAC to those who did not.[2-6]  Although understanding the attributes of different studies could make up its own blog entry, graduate-level course, or even research career, we will just say here that a randomized-controlled trial is widely considered the best possible design for clinical trials.  So what did these trials reveal?  A small (5-10% absolute and 16-33% relative improvement in survival) – but significant – overall survival benefit in patients who received NAC prior to surgery.

As could be expected, there was significantly better survival among patients who achieved pT0 status, whether they underwent NAC or not.  The main advantage was that more patients who received NAC were found to be pT0 than those who went straight to surgery (and it is hypothesized that the increased number of pT0 patients accounts for the survival benefits observed).  Of course, even well-performed trials are not perfect, and Dr. Lavery and colleagues describe the limitations of the studies in detail.  Acknowledging this, the trials seem to confirm two critical pieces of information: 1) patients with no visible tumor in the bladder at the time of surgery have better survival, and 2) use of NAC gives patients a better chance of being tumor-free at surgery.  While these trials are not perfect, they provide the best available insight as to the effects of NAC in the setting of surgery.

What are the pros and cons of NAC?

Like most treatments, chemotherapy offers potential benefit at the risk of unwanted side effects.  The hope is of course that NAC, in combination with surgery, will cure the body of cancer completely.  As described above, we have fairly strong evidence that these treatments can achieve that in some patients.  Unfortunately, many cancers treated with chemotherapy will not respond, and in these cases, patients are subjected to the side effects of treatment without gaining significant benefit.  Identifying which tumors will and will not respond to chemotherapy is an area of active research, but as of yet we cannot predict this, and therefore we cannot restrict NAC to only those patients who will benefit from it.  In addition to the toxic side effects of chemotherapy, another drawback of NAC is that it inevitably delays surgery, usually for between 3 and 6 months.  While it is generally presumed that chemotherapy protects against the spread of cancer during this time, there are no studies which have looked specifically at this question.  It is therefore impossible to rule out the potential for cancer to spread outside the bladder during the delay prior to surgery.

Are these recommendations right for me?

As described above, the potential benefit of chemotherapy will have to be weighed against its side effects, which can range from life-threatening (e.g. blood disorders) to unpleasant (e.g. nausea).  A discussion with your physician should consider both your body’s ability to tolerate such side effects and your desire to do so in exchange for an uncertain benefit.  In the future, we hope that additional research can allow us to identify which patients will benefit from chemotherapy – and, better yet, lead to the development of more effective, less toxic therapies.  Until that time, deciding whether NAC is the right choice for each individual remains a difficult decision, but one that patients can aim to answer with the support of their friends, family, and healthcare team.

Jeffrey Tosoian, MD

Nilay Gandhi, MD

 This blog entry was written by Brady Urology Residents Jeffrey Tosoian, MD and Nilay Gandhi, MD.  

[1] Hugh J. Lavery, Kristian D. Stensland, Guenter Niegisch, Peter Albers, Michael J. Droller, Pathological T0 Following Radical Cystectomy with or without Neoadjuvant Chemotherapy: A Useful Surrogate, The Journal of Urology, Volume 191, Issue 4, April 2014, Pages 898-906, ISSN 0022-5347, http://dx.doi.org/10.1016/j.juro.2013.10.142.

[2] Advanced Bladder Cancer (ABC) Meta-analysis Collaboration: Neoadjuvant chemotherapy in invasive bladder cancer: update of a systematic review and meta-analysis of individual patient data advanced bladder cancer (ABC) meta-analysis collaboration.  Eur Urol, 48 (2005), p. 202

[3] H.B. Grossman, R.B. Natale, C.M. Tangen et al.  Neoadjuvant chemotherapy plus cystectomy compared with cystectomy alone for locally advanced bladder cancer.  N Engl J Med, 349 (2003), p. 859

[4] A. Sherif, E. Rintala, O. Mestad et al.  Neoadjuvant cisplatin-methotrexate chemotherapy for invasive bladder cancer—Nordic Cystectomy Trial 2 Scand J Urol Nephrol, 36 (2002), p. 419

[5] E. Rintala, E. Hannisdahl, S.D. Fosså et al.  Neoadjuvant chemotherapy in bladder cancer: a randomized study. Nordic Cystectomy Trial I.  Scand J Urol Nephrol, 27 (1993), p. 355

[6] International Collaboration of Trialists, Medical Research Council Advanced Bladder Cancer Working Party (now the National Cancer Research Institute Bladder Cancer Clinical Studies Group), European Organisation for Research and Treatment of Cancer Genito-Urinary Tract Cancer Group et al.  International phase III trial assessing neoadjuvant cisplatin, methotrexate, and vinblastine chemotherapy for muscle-invasive bladder cancer: long-term results of the BA06 30894 trial. J Clin Oncol, 29 (2011), p. 2171

AUA 2014 Outstanding Posters

The American Urological Association (AUA) Annual Meeting, 2014 has been a tremendous success for the Brady Urological Institute.  With greater than 60 faculty and research presentations over a five day period, members of the Brady team have been extremely busy sharing our discoveries with the world.  On Saturday, May 18, 2014, 36 presentations were awarded "Outstanding Poster" designations for the entire meeting in three categories: benign disease, oncology and research.  Brady researchers were awarded two Outstanding Poster Awards, which we share below:

OUTSTANDING POSTER #1

OP1-04: Identification and Validation of Protein Biomarkers of Response to Neoadjuvant Chemotherapy in Muscle Invasive Urothelial Carcinoma 

Alexander Baras*, Nilay Gandhi, Enrico Munari, Sheila Faraj, Mohammad Hoque, Mark Schoenberg, Trinity Bivalacqua, George Netto, Baltimore, MD

Summary: Neoadjuvant chemotherapy improves survival for patients undergoing radical cystectomy for muscle-invasive urothelial cancers of the bladder.  The greatest survival benefit is seen in those patients in whom all cancer is eradicated from the bladder (pT0).  However, the prognosis for patients who fail to respond to chemotherapy or progress while on chemotherapy is poor.  Predicting who will and will not respond to chemotherapy has huge importance in this area.  Researchers from Hopkins identified two genetic markers that could be identified from tissue obtained prior to chemotherapy, to assess the potential response to the medication.  Further studies are needed, however these data may help identify patients best served by chemotherapy and those who should forego chemotherapy for a rapid cystectomy.

Introduction and Objectives Neoadjuvant chemotherapy (NAC) results in 5-10% increase in 5-year survival rate in muscle invasive bladder cancer (MIBC) patients. More importantly, those who achieve a complete response (ypT0) have a 5 year survival rate of 80% as opposed to 40% for those who do not. However, NAC is not widely utilized due to concerns related to delay of cystectomy, potential side-effects, and inability to predict effectiveness. Recently suggested molecular signatures of chemoresponsiveness, which could prove useful in this setting, are yet to be translated into clinical practice. 
Methods mRNA expression data from a prior report on a NAC-treated MIBC cohort (Kato et. al) were analyzed in combination with the antibody database of the Human Protein Atlas (HPA). We identified classifier candidate biomarkers that can be detected by immunohistochemistry (IHC) in TURB biopsy material prior to NAC. The candidate biomarkers were subsequently validated in an independent cohort of 52 MIBC specimens. Response to NAC was defined as the lack of residual MIBC at cystectomy. 
Results By filtering based on large amplitude mRNA changes and the area under the receiver operator curve (AUROC), we identified 21 genes whose mRNA expression profiles differentiate response to NAC (n=33), Figure 1A. Using the HPA, we found that commercially available antibiodies to the protein products of 8 of these genes exhibited differential staining across a set of urothelial carcinomas cataloged in the HPA. In addition, 12 normal tissues were identified from the HPA that can serve as positive and negative controls for the 8 proteins. Our initial studies with 2 of these markers in a multivariate logistic regression model have yielded strong performance (80% accuracy) in identifying patients in our independent validation cohort that are not likely to benefit from NAC due to chemoresistance (Fischer’s exact test p-value 0.02), Figure 1B & 1C. 
Conclusions We illustrate the feasibility of translating gene expression signature data on NAC response into an IHC classifier applicable to TURB specimens. The performance achieved by the initial two markers in our study is being further characterized and the other putative protein markers are being assessed in our TMA cohort. 

OUTSTANDING POSTER #2

OP1-10: Rho-kinase inhibition prevents nNOS uncoupling in the MPG, erectile dysfunction and increases neuronal outgrowth following cavernous nerve injury 

Johanna Hannan*, Xiaopu Liu, Ahmet Hoke, Arthur Burnett, Trinity Bivalacqua, Baltimore, MD
Funding: NIH K08DK090370 and Urology Care Foundation.

Summary: Post-radical prostatectomy erectile dysfunction is a major issue faced by many patients and urologists today.  In order to potentially improve ED, inhibition of molecules that potentiate nerve injury, RhoA and RhoKinase (ROCK), an experimental medication was given to rats with a nerve injury.  This experiemental medication, U-27632, a ROCK inhibitor, improved post-nerve injury erectile function by preventing nitric oxide degeneration and promoting nerve regrowth and regeneration.  This may be a medication suitable to prevent post-prostaetectomy ED in the future.

Introduction and Objectives RhoA and Rho-kinase (ROCK) are implicated in the inhibition axonal growth/neurite sprouting, and neurodegeneration via regulation of inflammation and apoptosis following peripheral nerve injury. We hypothesize that degeneration of the cavernous nerve (CN) after injury is due to increased RhoA/ROCK signaling in the major pelvic ganglion (MPG) leading to neuronal nitric oxide synthase (nNOS) uncoupling and nerve degeneration. This study aimed to characterize the role of ROCK inhibition in preserving erectile responses, penile contractions, nNOS uncoupling and neurite outgrowth following bilateral cavernous nerve injury (BCNI). 
Methods Male Sprague-Dawleys rats (12 wks) were separated into sham, BCNI and BCNI treated with Y-27632 (ROCK inhibitor, 5 mg/kg twice daily; n=8/group). 14 days after BCNI, groups underwent CN stimulation to determine erectile function. Penes were dissected and contractile responses to phenylephrine (PE) and electrical field stimulation (EFS) were assessed. MPGs were excised and protein (Western blots) and gene expression (q-PCR) of nNOS and growth associated protein 43 (GAP43) were assessed. Additional MPGs (n=3/group) were cultured in reduced growth factor matrigel for 48h and neurite growth was measured. 
Results While erectile function was severely decreased in BCNI rats, daily administration of Y-27632 improved erections 2-fold (p<0.05). nNOS MPG gene expression was decreased by 50% after BCNI and recovered to sham levels with Y-27632 (p<0.05). nNOS uncoupling was increased in BCNI MPGs and completely prevented in y-27632 treated rats (p<0.05). Cavernous contractile responses to PE were unchanged. EFS-mediated penile contractions were significantly lower following BCNI and treatment with Y-27632 increased EFS-mediated contractions 2-fold compared to sham and BCNI penes (p<0.05). MPG neurite outgrowth was unchanged in sham and BCNI; however, BCNI+Y MPGs had significantly increased growth (S:328±9μm; BCNI:349±14μm; BCNI+Y:405±11μm, p<0.05). GAP43, a growth protein highly expressed during axonal regeneration, was increased 25% following BCNI and 30% with Y-27632 treatment indicating treatment increased axonal growth. 
Conclusions Inhibition of ROCK preserved erections, prevented nNOS uncoupling, mediated increased neurite growth and increased nerve-mediated penile contractions in BCNI rats. Preventing the activation of RhoA/ROCK signaling in the MPG and CN after injury may inhibit neurodegeneration and post-radical prostatectomy erectile dysfunction. 


For more Brady Urological Presentations, visit the AUA2014 Website or stay tuned.

Upper Tract Urothelial Cancer Chemotherapy: When? For Whom?

Urothelial cancer refers to cancer of the lining of the urinary tract and was previously known as transitional cell carcinoma.  Urothelial cancers can occur in the bladder or the upper tract of the urinary system which includes the lining of the kidney (otherwise known as the renal pelvis) and the ureter.  Biologically, upper tract urothelial cancers (UTUC) are similar to urothelial cancers of bladder.  However, they have several important distinctions:

• UTUC is rare, accounting for only 5% of all urothelial cancers. [1]
• UTUC are more difficult to visualize and treat endoscopically.
• UTUC are morphologically similar to bladder cancers but have different embryologic origins and genetic characteristics.  
• Like urothelial cancer of the bladder, stage (i.e. depth of invasion) is the most important predictor of prognosis.  However, unlike the bladder, grade is highly correlated to stage:
• 91% of high-grade tumors in the renal pelvis are invasive
• 64% of high-grade tumors in the ureter are invasive [2] 
• Prognosis is different for UTUC compared to urothelial cancer of the bladder.
• Upwards of 19% of patients with UTUC present with metastases.[3]
• However, in matched cohorts with less aggressive disease, progression and death occurred with equal frequency among patients with UTUC and bladder cancers.[4] 
• The role of neoadjuvant and adjuvant chemotherapy is not well-established in UTUC (see below).

The last important distinction is that chemotherapy is almost considered "standard-of-care" either before or after removal of the bladder in certain circumstances.  Adjuvant chemotherapy (AC or chemotherapy immediately after surgery without any evidence of metastases) has an established niche for patients with adverse pathological features at the time of radical cystectomy for urothelial cancer of the bladder.
Similarly, neoadjuvant chemotherapy (NAC or chemotherapy before surgery) has a growing role in the treatment of muscle-invasive urothelial cancer of the bladder (please see prior blog entry Neoadjuvant Chemotherapy for Bladder Cancer: What Does It All Mean?). 

The role of NAC prior to nephroureterectomy (NU or removal of the kidney and ureter) or AC following surgery is less well-understood.  The lack of data supporting the use of either NAC or AC is based mostly on the poor overall survival rate for patients with high-grade and high-stage UTUC regardless of treatment and the subsequent lack of overall response rate to chemotherapy.  

However, there are a number of reasons that chemotherapy surrounding surgery makes sense.  First, patients with locally advanced disease experience a 50% or greater risk of progression and less than a 2-year median survival duration.[5-8]  Therefore surgery alone is not curative and the addition of a systemic therapy may improve cancer outcomes.   

Here we review the limited data regarding AC and NAC in the treatment of UTUC.

Adjuvant Chemotherapy (AC) Following Nephroureterectomy (NU)

A recent, systematic review of AC following NU examined one prospective study and nine retrospective studies (no randomized trials were available) comparing 482 patients receiving AC after NU and 1300 patients undergoing NU alone.  This analysis demonstrated a 50% reduction in disease recurrence and 60% reduction in overall death in favor of those patients receiving AC.[9]  Importantly, this was a heterogeneous group of patients with pT2-4, node-negative and node-positive disease; and all patients receiving AC had adequate renal function.         

Neoadjuvant Chemotherapy (NAC) Prior to Nephroureterectomy (NU)

There are a number of specific reasons why NAC before NU makes sense:

• NAC works for the bladder.
• Survival is improved 5-10% with chemotherapy before surgical removal of the bladder.
• UTUC is biologically similar to urothelial cancer of the bladder.
• NAC effectively down-stages urothelial cancer (discussed below)
• Many patients who undergo NU are not eligible for chemotherapy after surgery because they are older and/or have baseline chronic kidney disease.
• The best chemotherapies for urothelial cancer are filtered by the kidneys.
• Reduced filtering ability of the kidneys can cause:
• decreased efficacy of chemotherapy
• increased toxicities including worsening renal function

In two retrospective series of patients receiving NAC compared to historical patients undergoing NU alone, there was a significant proportion of down staging in the NAC group with a 14% complete response rate.[10]  The follow-up study demonstrated a 90% cancer-specific survival rate at 5-years compared to 57% in the NU alone group.[11]  A meta-analysis of NAC data demonstrated a disease-specific survival improvement of nearly 60% for NAC in retrospective studies; and favorable pathologic downstaging rates and survival rates upwards of 90% in two, prospective phase 2 NAC trials.[9]

Summary

Chemotherapy should play a role in the treatment of UTUC, should be considered in the time period surrounding NU and should be discussed as an option with patients.

  

Adjuvant Chemotherapy (AC) can improve cancer-recurrence rates and overall survival.  AC should be considered following NU in patients with:

• adequate renal function
• high-risk pathological features (pT3 or pT4, N1 or positive surgical margins)

Neoadjuvant Chemotherapy (NAC) effectively downstages tumors and may improve survival in limited studies.  NAC should be considered prior to NU in patients:

• invasive high-grade UTUC
• high-volume, high-grade UTUC with clinical suspicion of invasive disease
• baseline renal dysfunction that may preclude chemotherapy following surgery

More data and well-designed prospective studies are needed to define the exact role and benefits of AC and NAC in UTUC.

This entry was written by Phillip M. Pierorazio, MD, Assistant Professor of Urology and Oncology at the Brady Urological Institute at Johns Hopkins.

[1] Melamed MR, Reuter VE: Pathology and staging of urothelial tumors of the kidney and ureter. Urol Clin North Am 1993; 20: 333

[2] McCarron JP Jr, Mills C, Vaughn ED Jr. Tumors of the renal pelvis and ureter: current concepts and management. Semin Urol 1983;1:75–81.

[3] Akaza H, Koiso K, Niijima T,et al: Clinical evaluation of urothelial tumors of the renal pelvis and ureter based on a new classification system. Cancer 1970; 26: 58

[4] Catto JW, Yates DR, Rehman AR,et al: Behavior of urothelial carcinoma with respect to anatomic location. J Urol 2007; 177: 1715-1720

[5] Brown GA, Busby JE, Wood CG, et al. Nephroureterectomy for treating upper urinary tract transitional cell carcinoma: time to change the treatment paradigm? BJU Int. 2006; 98: 1176-1180.

[6] Hall MC, Womack S, Sagalowsky AI, Carmody T, Erickstad MD, Roehrborn CG. Prognostic factors, recurrence, and survival in transitional cell carcinoma of the upper urinary tract: a 30-year experience in 252 patients. Urology. 1998; 52: 594-601.

[7] Lehmann J, Suttmann H, Kovac I, et al. Transitional cell carcinoma of the ureter: prognostic factors influencing progression and survival. Eur Urol. 2007; 51: 1281-1288.

[8] Ozsahin M, Zouhair A, Villa S, et al. Prognostic factors in urothelial renal pelvis and ureter tumours: a multicentre Rare Cancer Network study. Eur J Cancer. 1999; 35: 738-743.

[9] Jeffrey J. Leow, William Martin-Doyle, André P. Fay, Toni K. Choueiri, Steven L. Chang, Joaquim Bellmunt, A Systematic Review and Meta-analysis of Adjuvant and Neoadjuvant Chemotherapy for Upper Tract Urothelial Carcinoma, European Urology, Available online 16 March 2014, ISSN 0302-2838, http://dx.doi.org/10.1016/j.eururo.2014.03.003.

[10] S.F. Matin, V. Margulis, A. Kamat et al.  Incidence of downstaging and complete remission after neoadjuvant chemotherapy for high-risk upper tract transitional cell carcinoma.  Cancer, 116 (2010), pp. 3127–3134

[11] S. Porten, A. Siefker-Radtke, A. Kamat, C. Dinney, S. Matin.  Survival outcomes in patients undergoing neoadjuvant chemotherapy for upper tract urothelial cell carcinoma [abstract].  J Clin Oncol (Suppl 6) (2013), p. 311

Stage 1 Testis Cancer: Recommendations from Hopkins

Testicular cancer is one of the true success stories in modern medicine.  With modern chemotherapy regimens, the overall cure rate for men with early stage (Clinical Stage I, CSI) testis cancer approaches 100%.  Given that these patients are often young men - each with a long life expectancy - consideration of side-effect profiles, specifically "late-effect" profiles (those occurring 10 or greater years after treatment), are of paramount consideration.

Focusing on men with non-seminomatous germ cell tumors (NSGCT), the National Cancer Comprehensive Network (NCCN) outlines three management strategies for men with CSI NSGCT:

• Active Surveillance (AS)
• Primary Chemotherapy
• Nerve-Sparing Retroperitoneal Lymph Node Dissection (RPLND)

When choosing a management strategy for CSI NSGCT, the primary point of distinction is the presence of lymphovascular invasion (LVI) in the primary tumor in the testicle.  If no LVI is present, the risk of recurrence is low (15% or less) and these patients are classified as Clinical Stage Ia.  If LVI is present, the risk of recurrence is much higher (approaching 50%) and those patients are considered Clinical Stage Ib.  However, both CSIa and CSIb men have excellent cure rates with even those patients who recur being salvaged with chemotherapy and/or surgery.

Recently there has been a large impetus for active surveillance for men with CSI NSGCT.[1,2]  Here we review the management options, some of the literature and debate on this topic.

Active Surveillance for Clinical Stage I Disease

According to the NCCN Guidelines, AS is a relatively time- and radiology-intense follow-up that eases only after 5 years and continues indefinitely (see table).  AS has been demonstrated to be safe and effective treatment for CSI NSGCT.[3-7]  Protocols have been refined to be less intense, and continue to demonstrate excellent long-term survival rates.[8,9]  However, some of the issues with AS include: 

• Compliance - the testis cancer population, in general, is young and mobile; adherence to AS protocols can be difficult
• Radiation Exposure - repeat CT imaging over a life-time has a small, but not insignificant radiation exposure that should be addressed in young men
• Salvage - if recurrence while on AS, the most likely next treatment is chemotherapy, with the potential long-term side effects of chemotherapy (discussed in next section)

NCCN Guidelines for Surveillance of Patients with CSI NSGCT.

Primary Chemotherapy for Clinical Stage I Disease

The typical chemotherapy for patients with CSI NSGCT is BEP (a combination of bleomycin, etoposide and cisplatin) for one- or two-cycles.  Primary chemotherapy in this setting reduces the risk of recurrence to <1%, however will overtreat 50-85% of men.  The short-term side effects of chemotherapy are well-known (hair loss, nausea and vomiting, etc) and, in general, short-lived and well-tolerated in this young, healthy population.  Of important consideration, is that these men are subjected to the long-term side effects of chemotherapy without actually needing the drug.  

Late-effect side effects of chemotherapy:

• Secondary Malignancy: 
• Solid tumors: Relative Risk 1.8-2.1 [10,11] 
• Leukemia: 0.5-2% based on dose of etoposide [12], variably increased based on the dose of cisplatinum [13]
• Cardiovascular Toxicity: demonstrated increased risks of early-onset angina, myocardial infarcation (heart attack) with related hyperlipidemia, metabolic syndrome [14-16]
• Single-Organ Dysfunction:
• Neurotoxicity: approximately 20% have neurologic symptoms [17]
• Nephrotoxicity: 30% long-term reduction in glomerular filtration rate (kidney filtering) [18,19]
• Pulmonary Toxicity: 
• Increased risk of pulmonary disease and death from pulmonary disease [20]
• Most of this toxicity is related to bleomycin, as it can have long-term effects on pulmonary function by causing pulmonary fibrosis
• This was a major reason Lance Armstrong sought to avoid this chemotherapy.
• Hypogonadism (Decreased Testosterone)
• Infertility
• Unknown toxicities: cisplatinum chemotherapy can be found in the blood of patients 10 years after receiving a dose.  The long-term side effects of this medication are currently unknown. [21]

Other considerations before accepting chemotherapy include: (1) most recurrences after parimary chemotherapy are teratoma and occur in the retroperitoneum, necessitating serial abdominal imaging similar to an AS protocol, and (2) treatment for recurrence after chemotherapy is RPLND.  Post-chemotherapy RPLND can be a challenging and dangerous operation.  While complications are rare they can be serious, occasionally catastrophic and include:

• life-threatening bleeding requiring blood transfusion or reconstruction of vascular structures
• removal of adherent adjacent organs (small bowel, kidney, etc.)
• permanent anejaculation
• chylous ascites

Primary Retroperitoneal Lymph Node Dissection (RPLND) for Clinical Stage I Disease

The primary landing zone for metastases from testis cancer are the lymph nodes of the retroperitoneum, around and between the aorta and inferior vena cava at the level of the kidneys.  For many years, RPLND was a mainstay of therapy for CSI NSGCT as it better staged disease and offered a therapeutic benefit for many patients.  However, upwards of 70% of patients will never need an RPLND and are overtreated by surgery.  RPLND has fallen out of favor with many physicians and organization due to the morbidity of the procedure and high-risk of overtreatment.

Traditionally, RPLND is done through a large, midline incision (along the entire abdomen) and only performed at high-volume, centers of excellence due to the rarity of disease and technical challenges of the surgery.  More recently, minimally-invasive RPLND has become an option for men with testis cancer, dramatically reducing the convalescence of the operation and offering the benefits of avoiding chemotherapy and rigorous AS.[22]  Minimally-invasive RPLND changes the thought-process for CSI testis cancer, as it changes the ratio of risk to benefit as the morbidity associated with the procedure is dramatically reduced compared with the traditional, open surgery.  In addition, post-chemotherapy RPLND is a dramatically different operation (discussed above).  Avoiding a post-chemotherapy RPLND can prevent many undesirable side-effects in young men.

What do we recommend for men with CSI NSGCT?

One of the common sayings in testis cancer is, "All roads lead to Rome," and that patients need to choose the road that most suits their personality, lifestyle and concerns.  Basically, nearly 100% of men with CSI NSGCT will be cured.  Some (actually a minority) will require chemotherapy, some surgery and some a combination of both.  We often recommend that patients consider what treatment they would like to avoid most and prioritize the order of the treatments (if needed) from there.  

We often recommend that patients consider what treatment they would like to avoid most and prioritize the order of the treatments (if needed) from there. 

While every patient is an individual and individual health risks and preferences need to be considered, in general, we make the following recommendations at the Brady Urological Institute at Johns Hopkins for the treatment of CSI NSGCT.

Clinical Stage Ia (Tumor Confined to the Testicle, No Lymphovascular Invasion)

Men with CSIa have an incredibily low-risk of recurrence (5-15%).  Therefore we do not routinely recommend primary treatment (chemotherapy or RPLND) as most patients will be overtreated by these therapies.

• Active Surveillance is preferred
• Upwards of 90-95% of men are cured with orchiectomy alone
• AS involves tumor markers and CT scans every 3-4 months after surgery
• Primary Chemotherapy is an option
• for patients concerned about the risk of relapse 
• for patients with compliance or insurance issues
• Primary Minimally-Invasive RPLND is an option
• for patients concerned about the risk of relapse 
• patients with compliance or insurance issues
• patients who wish to avoid a post-chemotherapy RPLND

Clinical Stage Ib (Tumor Confined to the Testicle, Lymphovascular Invasion present)  

Men with CSIb NSGCT have upwards of a 50% chance of recurrence.  Therefore, we usually recommend primary chemotherapy or minimally-invasive RPLND as treatment for these men.  

• Minimally-Invasive RPLND
• most patients are discharge one day after surgery (although full recovery certainly can take weeks)
• nodal yields and ejaculatory function are excellent with a unilateral template surgery
• patients with one-positive lymph node (N1) can be monitored following surgery without necessitating chemotherapy
• we recommend adjuvant chemotherapy for all patients with greater than one positive lymph node (N2)
• Primary Chemotherapy
• will cure many patients with high-risk, CSIb disease
• patients must consider that they will require a post-chemotherapy RPLND
• patients must consider late-term side effects of chemotherapy (excellent treatment for older patients)
• Active Surveillance remains an option
• for patients desiring to avoid all additional treatments
• patients need to recognize that those who recur after a period of AS, will require full-dose chemotherapy (3-4 cycles of BEP) and potentially more side effects

Phillip M. Pierorazio, MD is the Director of the Division of Testicular Cancer at the Brady Urological Institute at Johns Hopkins.  If you or a loved one was recently diagnosed with testis cancer and would like a consultation please call the Urology Clinic at 410 955 6100.  If you or a loved one is a survivor of testis cancer, please take a look at our Facebook page for "Testis Cancer Survivors."  The page is designed to be a forum for patients to meet and discuss issues around Testis Cancer.  We will supply the page with updates and data regarding Testis Cancer.

Resources:

NCCN website: http://www.nccn.org/professionals/physician_gls/pdf/testicular.pdf

[1] Nichols CR1, Roth B, Albers P, Einhorn LH, Foster R, Daneshmand S, Jewett M, Warde P, Sweeney CJ, Beard C, Powles T, Tyldesley S, So A, Porter C, Olgac S, Fizazi K, Hayes-Lattin B, Grimison P, Toner G, Cathomas R, Bokemeyer C, Kollmannsberger C.  Active surveillance is the preferred approach to clinical stage I testicular cancer.  J Clin Oncol. 2013 Oct 1;31(28):3490-3. doi: 10.1200/JCO.2012.47.6010. Epub 2013 Sep 3.

[2] Schmidt C. Debates emerge over active surveillance in testicular cancer.  J Natl Cancer Inst. 2014 Feb;106(2):dju040. doi: 10.1093/jnci/dju040.

[3] Duran I, Sturgeon JF, Jewett MA, et al: Initial versus recent outcomes with a non-risk adapted surveillance policy in stage I non-seminomatous germ cell tumors (NSGCT). J Clin Oncol 25:240s, 2007 (suppl; abstr 5021) 

[4] Kollmannsberger C, Moore C, Chi KN, et al: Non-risk-adapted surveillance for patients with stage I nonseminomatous testicular germ-cell tumors: Diminishing treatment-related morbidity while maintaining efficacy. Ann Oncol 21: 1296-1301, 2010

[5] Kollmannsberger C, Tyldesley S, Moore C, et al: Evolution in management of testicular seminoma: Population-based outcomes with selective utilization of active therapies. Ann Oncol 22:808-814, 2011

[6] Tandstad T, Smaaland R, Solberg A, et al: Management of seminomatous testicular cancer: A binational prospective population-based study from the Swedish Norwegian Testicular Cancer Study Group. J Clin Oncol 29:719-725, 2011.

[7] Tandstad T, Dahl O, Cohn-Cedermark G, et al: Risk-adapted treatment in clinical stage I nonseminomatous germ cell testicular cancer: The SWENOTECA management program. J Clin Oncol 27:2122-2128, 2009.

[8]  Rustin GJ, Mead GM, Stenning SP, et al. (2007) Randomized trial of two or five computed tomography scans in the surveillance of patients with stage I nonseminomatous germ cell tumors of the testis: Medical Research Council Trial TE08, ISRCTN56475197–the National Cancer Res Institute Testis Cancer Clinical Studies Group. J Clin Oncol 25:1310–1315.

[9] Cathomas R, Helbling D, Stenner F, et al. (2010) Interdisciplinary evidence-based recommendations for the follow-up of testicular cancer patients: A joint effort. Swiss Med Wkly 140:356–369.

[10] Travis LB, Fossa SD, Schonfeld SJ, et al. Second cancers among 40,576 testicular cancer patients: focus on long-term survivors. J Natl Cancer Inst 2005;97(18):1354-1365.

[11] van den Belt-Dusebout AW, de Wit R, Gietema JA, et al. Treatment-specific risks of second malignancies and cardiovascular disease in 5-year survivors of testicular cancer. J Clin Oncol 2007;25(28):4370-4378.

[12] Kollmannsberger C, Hartmann JT, Kanz L, et al. Therapy-related malignancies following treatment of germ cell cancer. Int J Cancer 1999;83(6):860-863.

[13] Travis LB, Andersson M, Gospodarowicz M, et al. Treatment-associated leukemia following testicular cancer. J Natl Cancer Inst 2000;92(14):1165-1171.

[14] Meinardi MT, Gietema JA, van der Graaf WT, et al. Cardiovascular morbidity in long-term survivors of metastatic testicular cancer. J Clin Oncol 2000;18(8):1725-1732.

[15] van den Belt-Dusebout AW, Nuver J, de Wit R, et al. Long-term risk of cardiovascular disease in 5-year survivors of testicular cancer. J Clin Oncol 2006;24(3):467-475.

[16] Haugnes HS, Aass N, Fossa SD, et al. Components of the metabolic syndrome in long-term survivors of testicular cancer. Ann Oncol 2007;18(2):241-248.

[17] Mykletun A, Dahl AA, Haaland CF, et al. Side effects and cancer-related stress determine quality of life in long-term survivors of testicular cancer. J Clin Oncol 2005;23(13):3061-3068.

[18] Hansen SW, Groth S, Daugaard G, et al. Long-term effects on renal function and blood pressure of treatment with cisplatin, vinblastine, and bleomycin in patients with germ cell cancer. J Clin Oncol 1988;6(11):1728-1731.

[19] Fossa SD, Aass N, Winderen M, et al. Long-term renal function after treatment for malignant germ-cell tumours. Ann Oncol 2002;13(2):222-228.

[20] Fossa SD, Gilbert E, Dores GM, et al. Noncancer causes of death in survivors of testicular cancer. J Natl Cancer Inst 2007;99(7):533-544.

[21] Travis LB, Beard C, Allan JM, Dahl AA, Feldman DR, Oldenburg J, Daugaard G, Kelly JL, Dolan ME, Hannigan R, Constine LS, Oeffinger KC, Okunieff P, Armstrong G, Wiljer D, Miller RC, Gietema JA, van Leeuwen FE, Williams JP, Nichols CR, Einhorn LH, Fossa SD.Testicular cancer survivorship: research strategies and recommendations. J Natl Cancer Inst. 2010 Aug 4;102(15):1114-30. doi: 10.1093/jnci/djq216. Epub 2010 Jun 28.

[22] Hyams ES1, Pierorazio P, Proteek O, Sroka M, Kavoussi LR, Allaf ME.Laparoscopic retroperitoneal lymph node dissection for clinical stage I nonseminomatous germ cell tumor: a large single institution experience. J Urol. 2012 Feb;187(2):487-92. doi: 10.1016/j.juro.2011.10.035. Epub 2011 Dec 16.