Increasing use of radical prostatectomy for non-lethal prostate cancer in Sweden.

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Abstract:

PURPOSE: The number of patients in Sweden treated with radical prostatectomy for localized prostate cancer has increased exponentially. The extent to which this increase reflects treatment of non-lethal disease detected through PSA screening is unknown. Experimental design: We undertook a nationwide study of all 18,837 prostate cancer patients treated with radical prostatectomy in Sweden from 1988 to 2008 with complete follow-up through 2009. We compared cumulative incidence curves, fit Cox regression and cure models, and performed a simulation study to determine changes in treatment, cancer-specific survival over time, and effect of lead-time due to PSA screening. RESULTS: The annual number of radical prostatectomies increased 25-fold during the study. Five-year cancer-specific mortality decreased from 3.9% (95% CI 2.5 to 5.3) among patients diagnosed between 1988 and 1992 to 0.7% (95% CI 0.4-1.1) among those diagnosed between 1998 and 2002 (p for trend < 0.001). According to the cure model, the risk of not being cured declined by 13% (95% CI 12-14%) with each calendar year. The simulation study indicated that only half of the improvement in disease-specific survival could be accounted for by lead-time. CONCLUSION: Patients overdiagnosed with non-lethal prostate cancer appear to account for a substantial and growing part of the dramatic increase in radical prostatectomies in Sweden but increasing survival rates are likely due to true reductions in risk of disease-specific death over time. Because the magnitude of harm and costs due to overtreatment can be considerable, identification of men who likely benefit from radical prostatectomy is urgently needed.