When and if BCG fails, patients are left with the difficult choice of proceeding to radical surgery or, often unproven, additional intravesical therapies. Here we present some of the data on additional immunotherapies for the treatment of bladder cancer.
See our prior blog onThe ability of IFN-α to fight off cancers has been attributed to both an ability to stop cell growth and its immunomodulatory effects. Because of its ability to augment the local immune response, IFN-α2b has been studied in conjunction with BCG. There is only one published, randomized trial comparing BCG alone to BCG+IFN. This group of patients did not receive any prior intravesical treatments, and there was no significant difference in recurrence-free survival at two years, although the IFN group did exhibit a higher incidence of constitutional symptoms and fever . for a better understanding of stimulating the immune system for the treatment of bladder cancer.
IFN-α may play a role in patients who have failed an initial course of intravesical BCG therapy. A study of 40 patients failing one or more courses of BCG showed a disease-free rate of 53% at 24 months when they went on to receive 6-8 weekly instillations of low-dose BCG plus IFN-α . A multicenter trial including 467 patients with previous BCG failure demonstrated a disease-free rate of 45% after being treated with reduced-dose BCG and IFN-α . Risk factors for recurrence were stage T1, tumor size >5 cm, multifocality, more than one prior BCG failure and age >80.
Timing of recurrence predicts effectiveness of BCG, IFN-α combination therapy. Patients with recurrence >12 months after initial BCG treatment who were treated with low-dose BCG plus IFN-α had a disease-free rate of 53-66% at 24 months. However, patients with recurrence within one year did poorly, with a disease-free rate of 34-43% at two years.
Therefore, combination therapy with both BCG and IFN-α may have a salvage role in patients with single course BCG failure or late relapse, while those who recur quickly after initial BCG treatment may be destined to failure and better served by radical cystectomy.
INTERLEUKIN-2 (IL-2)Interleukin (IL)-2 is a cytokine that enhances the production of cytotoxic lymphocytes capable of lysing tumor cells while leaving benign cells unharmed -- IL-2 activated lymphocytes are known as “lymphocyte-activated killer” or LAK cells [8,9]. Additionally, IL-2 augments the immune system through a variety of interactions with NK cells, monocytes and Th1 cells [9,10].
IL-2 is poorly tolerated when given systemically, however intravesical administration has a much improved side effect profile [11,12]. In a small cohort, intravesical IL-2 administered after incomplete TUR of low grade T1 papillary UC demonstrated regression of the “marker lesion” in 8 of 10 patients . Animal models with recombinant IL-2-secreting strains of BCG have shown an enhanced antitumor cytotoxicity and local immune response when compared with BCG alone [14-16].
INTERLEUKIN-10 (IL-10)Interleukin-10 (IL-10) is an inhibitor of immune response, decreasing the production of several cytokines produced by Th1, including IFN-γ . Several initial studies demonstrated an improved BCG and local immune response in IL-10 knockout mice after being inoculated with bladder cancer with greater antitumor activity and prolonged survival [10, 25, 26]. Therefore, more recent research has attempted to block the IL-10 receptor. Mice treated with BCG and an anti-IL-10 receptor antibody show improved overall and tumor-free survival when compared to BCG controls -- although not all of these differences reached statistical significance . Further testing showing more confirmatory results is necessary but these initial results are promising.
- Interferon-alpha may be effective for patients who have failed an initial course of BCG.
- IFN-α is not more effective than BCG alone for initial treatment.
- Patients who recur quickly after the first dose of BCG are less likely to benefit from IFN-α.
- Interleukin-2 and -12 have immunostimulatory effects and have demonstrate some efficacy for treating bladder cancer in animal models.
- Interleukin-10 is an inhibitor of immune response and animal studies blocking this cytokine have promising early results.
This entry was written by Nilay M. Gandhi, MD, senior assistant resident at the Brady Urological Institute at Johns Hopkins.
Some of the data is extracted from the chapter Intravesical Immunotherapy - Bladder Cancer: Diagnosis and Clinical Management by Nilay M. Gandhi, Laura A. Bertrand, Donald L. Lamm, and Michael A. O’Donnell which will appear in newest edition of The Textbook of Bladder Cancer.
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 Nepple KG, Lightfoot AJ, Rosevear HM, et al; Bladder Cancer Genitourinary Oncology Study Group. Bacillus Calmette-Guérin with or without interferon α-2b and megadose versus recommended daily allowance vitamins during induction and maintenance intravesical treatment of nonmuscle invasive bladder cancer. J Urol 2010; 184: 1915-9.
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 Gallagher BL, Joudi FN, Maymí JL, et al. Impact of previous bacillus Calmette-Guérin failure pattern on subsequent response to bacillus Calmette-Guérin plus interferon intravesical therapy. Urology 2008; 71: 297-301.
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