Predictive factors of oncologic outcomes in patients who do not achieve undetectable prostate specific antigen after radical prostatectomy.

ABSTRACT

PURPOSE: We identified factors predicting oncologic outcomes in cases of persistently detectable prostate specific antigen. MATERIALS AND METHODS: We reviewed the charts of patients treated with radical prostatectomy between 1998 and 2011 at a total of 14 centers. Study inclusion criteria were radical prostatectomy for presumed localized prostate cancer, absent positive nodes and detectable prostate specific antigen, defined as prostate specific antigen 0.1 ng/ml or greater 6 weeks postoperatively. Of the 9,735 radical prostatectomy cases reviewed 496 (5.1%) were eligible for analysis. Predictive factors for oncologic outcomes were assessed in time dependent analyses using the Kaplan-Meier method and Cox regression models. RESULTS: At 6 weeks prostate specific antigen was 0.1 to 6.8 ng/ml. Biochemical progression was noted in 74.4% of patients and clinical metastasis was noted in 5%. The 2 most powerful predictors of general salvage treatment (vs radiotherapy) were postoperative prostate specific antigen greater than 1 ng/ml (OR 3.46, p=0.032) and prostate specific antigen velocity greater than 0.2 ng/ml per year (HR 6.01, p=0.001). Positive prostate specific antigen velocity was the single factor that independently correlated with the risk of failed salvage therapy (HR 2.6, p=0.001). The 5-year disease-free survival rate was 81.0% in patients with stable or negative prostate specific antigen velocity compared with 58.4% in those with positive prostate specific antigen velocity (p<0.001). CONCLUSIONS: Patients with detectable prostate specific antigen after radical prostatectomy have a poor biochemical outcome. We identified postoperative prostate specific antigen and prostate specific antigen velocity as independent predictors of progression and failed salvage treatment. In addition to pathological prognostic factors, these factors should be considered early to better stratify patients for adjuvant therapy.