Predictors of treatment after initial surveillance in men with prostate cancer: Results from CaPSURE

Purpose: Expectant management of prostate cancer or watchful waiting (WW) is a reasonable option for some men with clinically localized prostate cancer. We identified predictors of eventual prostate cancer treatment in a cohort of men initially choosing WW. Materials and Methods: We identified 457 men in the Cancer of the Prostate Strategic Urologic Research Endeavor data base selecting WW as initial management without subsequent treatment for at least 6 months. A subset of these men eventually received active treatment for prostate cancer. These groups were compared with respect to baseline clinical, sociodemographic characteristics and followup prostate specific antigen (PSA) characteristics using Kaplan-Meier life tables and Cox proportional hazards models to determine predictors of active treatment after WW. Results: Of the 457 men initially on WW 188 (41%) went on to active treatment at a median of 1.7 years after diagnosis. Baseline characteristics associated with progression to active treatment included younger age, higher level of formal education, higher PSA and higher Gleason grade. Actuarial freedom from treatment (that is continued WW) was 74% at 2, 63% at 3 and 49% at 5 years with androgen deprivation the most common form of therapy (72%). Men progressing to treatment had higher baseline and followup PSA as well as a significantly greater PSA change that those remaining on WW (7.2 vs -0.4 ng/ml). Other measures of PSA dynamics also predicted eventual active treatment. These observations persisted in multivariate models. Conclusions: WW is an appropriate and common form of treatment in many men with prostate cancer and about half remain on WW at 5 years. Our analysis of national practice patterns identified demographic, clinical and PSA characteristics associated with men who continue with this modality. Conversely these factors may help determine which men (for example higher risk/PSA) ultimately receive active treatment despite initial treatment preference and allow investigation of the effects of these interventions on cancer outcomes and quality of life.