Predictors of delayed therapy after expectant management for localized prostate cancer in the era of prostate-specific antigen.

OBJECTIVE: To identify risk factors for delayed cancer-directed intervention in modern era prostate cancer patients who initially elect expectant management.
MATERIALS AND METHODS: An observational, cohort study of expectantly managed patients, diagnosed with clinical T(1-4)NxM0 prostate cancer between 1993 and 2000 was carried out. Data including TNM stage, age, serum prostate-specific antigen (PSA), prostate gland volume by transrectal ultrasound, Gleason score, percent biopsies positive for cancer, imaging results, initial treatment selection, and outcome data were collected on all patients.
RESULTS: 192 of 561 patients (34.3%) elected expectant management, and follow-up data were available for 187 (97.4%) patients. With a median follow-up of 3.6 years, 90 (48.1%) patients had a cancer-directed intervention. Gleason score (p = 0.0097) and percent of positive biopsy cores (p = 0.03) were independent predictors of time to intervention. As expected, PSA doubling time became the most significant predictor of intervention (p = 0.0057) when added to the model. These independent covariates are able to characterize low-, intermediate- and high-risk groups for cancer-directed intervention.
CONCLUSIONS: Cancer-directed intervention is common in patients who choose expectant management in the PSA era. Gleason score and percent of positive biopsy cores predict cancer-directed interventions, thus, these patients may be least suitable for expectant management.