Active surveillance is the least invasive option for managing a kidney tumor. At Johns Hopkins, "active surveillance" is preferred to terms like "observation" or "watchful waiting," as these indicate a passive approach where we wait for something bad to happen. Active surveillance is, by definition, an involved process where patients and tumors are watched very closely, where tumor size and growth characteristics are monitored, and the need for treatment is reassessed on a regular basis.
Why active surveillance?Kidney tumors are biologically heterogeneous – this means they come in all shapes, sizes and behaviors. Some are completely benign tumors, some are cancers that behave like benign tumors and some can be very aggressive. Most small kidney tumors (less than or equal to 4cm) are either benign or behave like benign tumors. The bigger a tumor gets, the more likely it is a dangerous cancer and conversely, the smaller a tumor is, the more likely it is benign or behaves in a benign fashion. While Hopkins is an expert center for kidney surgery, not all patients need to undergo surgery – especially if they have a benign or benign-behaving tumor.
Who is a good patient for active surveillance?Several patient characteristics make active surveillance an attractive option:
- Tumor size: the smaller the tumor, the higher likelihood of having a benign or benign-behaving cancer.
- Tumors less than or equal to 4cm can safely undergo active surveillance, although the risk of cancer spreading from a tumor is smaller for tumors less than 3cm and is <1% for tumors <2cm.
- Older patients who are medically fragile: Since the risk that the small kidney tumor spreads is low, in patients with a short life expectancy (<10years) a discussion regarding active surveillance may be prudent. Many of these patients die WITH the kidney tumor rather than OF the kidney tumor.
- Patients with poor kidney function: Since any intervention on the kidney can cause further deterioration of kidney function, these patients may be better off selecting active surveillance. In some patients, further decline in kidney function puts the patient at risk of needing dialysis. Dialysis, while life-saving, may be associated with poor outcomes and a low quality of life. Ask your doctor about your creatinine level which is an indicator of kidney function (normal is around 1.0 mg/dl).
- Patients with hereditary forms of kidney cancer: This includes patients with Von-Hippel-Lindau (VHL), Birt-Hogg-Dube (BHD), or other conditions in which patients are at risk of having multiple and recurrent tumors in both kidneys. These tumors are typically placed on active surveillance until they reach 3cm or larger.
- Patients who are experiencing or recovering from an active serious medical problem:
- Active, serious medical issues can include patients with heart failure and/or significant vascular disease. These patients are excellent candidates for active surveillance as these chronic medical conditions increase the risks of surgery.
- An example of a recovering medical issue is patients who have drug eluting heart stents or patients who temporarily need to be on a blood thinner like warfarin (Coumadin). Kidney surgery/intervention can result in severe bleeding in these patients and thus a period of active surveillance until they can come off the blood thinners may be helpful to avoid a potential serious complication. A period of active surveillance until things stabilize should be entertained.
- Patients who are extremely anxious about having surgery or do not wish to have treatment: While urologists at Johns Hopkins are expert surgeons who perform a large number and variety of kidney surgeries safely, these surgeries are not without risks. Surgery is not for everyone.
What does active surveillance involve?The initial evaluation includes a complete history and consideration of other health risks, a thorough staging evaluation (imaging of the chest, abdomen, and pelvis) to make sure the tumor is confined to the kidney, blood work and urine tests to evaluate kidney function. After the initial evaluation, repeat imaging is recommended every six months for the first two years, and annually thereafter. However, active surveillance is often tailored to the patient and the protocol can be customized for each patient.
It is preferred that the first image is a CT scan or MRI with contrast (if the patient can receive contrast). After the first image, ultrasound is the recommended follow-up as there is no radiation, costs are relatively cheap and ultrasound is easy to perform. Tumor size and growth rates are evaluated with each image to determine if the tumor is changing in size or quality. Tumors are expected to change over time – the goal is to catch the dangerous ones before they grow too large or leave the kidney!!
Can these tumors be biopsied?Percutaneous renal mass biopsy is an option for patients considering both surgery and active surveillance. Biopsy can often provide information regarding the malignant or benign nature of the mass. However, we expect most small renal masses to be low-grade, benign-behaving tumors and renal biopsy is not very good at telling the "good" cancers from the "bad." Researchers at Johns Hopkins are working right now to improve the performance of renal biopsy. Therefore, we decide on an individual basis, with each patient, if biopsy will be helpful.
What are the "triggers" for intervention?Most renal masses grow at a slow and unpredictable rate. The average growth rate is about 1 millimeter per year, however some tumors can grow faster and some tumors can shrink away! The biggest trigger for intervention is overall tumor size. The risk of spread from the kidney increases from <1% at 2cm, to 2-3% at 3cm and 5-10% for tumors 4cm or larger. Growth rate (centimeters per year) is also a consideration and tumors that grow >0.5cm/year may indicate aggressive growth. With each active surveillance image, the need for intervention is reconsidered.
Can the tumor spread while on active surveillance?The answer to this is unfortunately, YES. However, for a well-selected patient the risk of this occurring on surveillance is very low (<2%). Each patient and tumor are unique and this risk should be discussed with your urologist.
In patients who elect for delayed intervention, are the results compromised?A study by Johns Hopkins urologists showed that a period of active surveillance did not alter results. In this study, patients delayed treatment of their small kidney mass by over 1 year. All were eventually treated with minimally invasive surgery successfully.
Does Johns Hopkins have an active surveillance program for kidney tumors?Yes. In 2009, Johns Hopkins urologists Mohamad Allaf, MD and Phillip M. Pierorazio, MD started the DISSRM (Delayed Intervention and Surveillance for Small Renal Masses) Registry. The DISSRM Registry now catalogues over 200 patients undergoing active surveillance at Johns Hopkins, Columbia University in New York, and Beth-Israel Deaconess Hospital in Boston. For more details, see our prior blog: Active Surveillance Proving Safe for Patients with Small Renal Masses. Patients in the program are followed in an identical fashion to patients who choose not to enroll in the program (see "What does active surveillance involve?" above). The program involves regular check-ups and questionnaires regarding quality of life, anxiety, and general well-being. In addition, patients have the option of contributing blood and urine samples to look for a blood or urine marker to detect kidney cancer and answer some other important questions for this disease. Benefits to enrolling in the DISSRM Registry include help with decision-making throughout the surveillance process, the gathering of data to help the next patient with a small renal mass, ensuring follow-up with the research team at Hopkins and, lastly, is extremely easy study in which to participate. After talking with an urologist at Hopkins, a patient can sign consent forms and enroll in the study. A designated DISSRM clinic meets monthly to follow patients enrolled in the study. However, not all patients need to remain at Hopkins and some patients can follow-up remotely – so long as imaging and blood work are sent to Hopkins.
For more information regarding management of Kidney Cancer or the DISSRM Registry contact Dr. Mohamad Allaf, Dr. Phillip Pierorazio, or Tina Driscoll, the study coordinator at 410-955-0163.
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 Rais-Bahrami S, Guzzo TJ, Jarrett TW, Kavoussi LR, Allaf ME. Incidentally discovered renal masses: oncological and perioperative outcomes in patients with delayed surgical intervention. BJU Int. 2009 May;103(10):1355-8