WHICH MEN WITH LOW-RISK PROSTATE CANCER SHOULD BE TREATED?

Purpose: Although active surveillance is an option for low-risk prostate cancer, the comparative effectiveness of active surveillance (AS) vs. immediate radical prostatectomy (RP) is unknown. In this study, we compare the efficacy of AS vs. RP for men diagnosed at different ages and with different baseline health statuses.

Method: A Monte Carlo simulation using a Markov Model was used to simulate the life course of men diagnosed with low-risk prostate cancer in the modern PSA era when treated with radical prostatectomy or monitored with active surveillance. Different starting ages from 50–75 and health statuses (poor health, average health, and excellent health as defined by 0.5×, 1.0×, and 1.5× average life expectancy without prostate cancer) were simulated. Disease progression probabilities and utilities were obtained from literature review. Life expectancy, number of years with treatment-related erectile dysfunction or incontinence, quality adjusted life expectancy (QALE), and a clinical incremental cost effectiveness ratio (ICER) (years with side effects per life year extended) for men undergoing radical prostatectomy or managed with active surveillance were estimated.

Result: For a man age 56 in excellent health, immediate RP vs. AS resulted in 0.7 additional quality-adjusted life years (QALYs), with 3.8 years incremental years of life at a cost of 7 additional years of erectile dysfunction (ED) or incontinence, yielding a clinical ICER of 1.8 years of side effects per additional year of life. For a man age 67 in poor health, RP vs. AS resulted in –0.3 QALYs, no benefit to life expectancy and 2.6 additional years of ED and incontinence. Overall, increased age and decreased health status resulted in preference for AS in terms of QALEs and increased clinical ICER, whereas decreased age and increased health status resulted in preference for immediate RP and a lower clinical ICER. These trends held in all sensitivity analyses testing parameter uncertainties. 

Conclusion: Age and health status are critical determinants for optimal management strategies following diagnosis of low-risk prostate cancer. For older men and men in poorer health with reduced life expectancies, active surveillance should be strongly considered as an alternative to immediate treatment. Individual patient valuations of life with side effects vs. increased life expectancy can be compared to the calculated clinical ICER to inform individual treatment decisions.