Population based study of use and determinants of active surveillance and watchful waiting for low and intermediate risk prostate cancer.

PURPOSE: Prior studies have reported the underuse of deferred treatment (ie active surveillance or watchful waiting) for low risk prostate cancer in the United States. We examined contemporary trends in active surveillance and watchful waiting in the nationwide Swedish prostate cancer registry. We also examined factors associated with selection of deferred management, which might provide insight into the rational diffusion of this important management strategy.
MATERIALS AND METHODS: We identified 57,713 men with very low risk (T1c, Gleason 6 or less, prostate specific antigen less than 10 ng/ml, prostate specific antigen density less than 0.20 ng/ml/cc, 2 or fewer positive biopsy cores or less than 25% of cores positive), low risk (T1-T2, Gleason 6 or less, and prostate specific antigen less than 10 ng/ml) and intermediate risk prostate cancer (T1-T2, Gleason 7 and/or prostate specific antigen 10 to 20 ng/ml) in the PCBaSe (Prostate Cancer database Sweden) from 1998 to 2011. Subclassification of very low risk disease, and active surveillance vs watchful waiting was possible beginning in 2007. We examined primary treatment selection by risk group and used logistic regression to evaluate factors associated with deferred treatment.
RESULTS: Overall 13,272 (46%) men with low risk and 8,695 (30%) with intermediate risk prostate cancer chose deferred treatment. Since 2007, 59%, 41% and 16% of very low, low and intermediate risk prostate cancer, respectively, chose active surveillance. Age was by far the strongest determinant of deferred treatment. Education, marital status and comorbidity were significantly but weakly associated with deferring treatment.
CONCLUSIONS: Deferred treatment for low and intermediate risk prostate cancer was frequently used in Sweden. Dissociating diagnosis from treatment in men with a low risk of progression can decrease the rate of overtreatment.