We tried to investigate this clinical dilemma using a decision-analytic approach. We developed a discrete event simulation model, a relatively novel technique in biomedical research that has its origins in the simulation of industrial systems. Using this model, we were able to simulate the individual course of thousands of kidney failure patients diagnosed with active surveillance-eligible prostate cancer. This cohort of hypothetical patients was then exposed to four different strategies regarding kidney failure management (i.e. waiting period versus direct listing) and prostate cancer treatment (i.e. definitive treatment by radical prostatectomy or radiation therapy versus active surveillance). To compare the strategies from an integrative healthcare perspective, we decided to use quality-adjusted life years (QALYs) as the primary outcome which measures both the quality and the quantity of life lived.
Our simulation shows that, among kidney failure patients diagnosed with active surveillance-eligible prostate cancer during pretransplantation workup, the strategy “active surveillance and immediate listing” (6.97 ± 0.01 QALYs) followed by the strategy “definitive treatment and immediate listing” (6.75 ± 0.01 QALYs) not only outperformed the strategies incorporating a waiting period of two years (definitive treatment: 6.32 ± 0.01 QALYs; active surveillance: 6.59 ± 0.01 QALYs) but also yielded a higher proportion of successfully performed transplantations (72% and 74% versus 56% and 59%), with less time on hemodialysis on average (4.02 and 3.81 years versus 4.80 and 4.65 years).
The implementation of an active surveillance approach in this specific population of kidney failure patients is accompanied by two main concerns: The belief that a post-transplant status might negatively interfere with definitive treatment options and the fear that immunosuppressive therapy negatively affects the risk of prostate cancer progression. However, current literature cannot back-up these concerns.
Based on our study, we not only advocate for the generous implementation of the well-accepted active surveillance paradigm among kidney failure patients being worked up for transplantation but also for immediate listing regardless of the ultimate decision between active surveillance and definitive treatment.
We hope that our study can improve decision-making in interdisciplinary transplantation boards faced with this clinical dilemma.
Written by: Uwe Bieri, MD, Department of Urology, University of Zurich, Zurich, Switzerland, Twitter: @UweBieri, Marian S. Wettstein, MD, PhD Candidate, Clinical Epidemiology & Health Care Research, University of Toronto, Toronto, Ontario, Twitter: @wettsteinms
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