Prognostic factors for multifocal prostate cancer in radical prostatectomy specimens: Lack of significance of secondary cancers

Purpose: We evaluated secondary cancers in the prostate in relation to predictions of pathological stage and prognosis. Materials and Methods: A total of 222 men with T1c (impalpable) prostate cancer and 6 or more systematic needle biopsies were matched with radical prostatectomy and classified into 3 groups according to tumor multifocality and secondary cancer volumes, including a single tumor in 54 (24%), an index (largest) tumor with secondary cancers less than 0.5 cc in 86 (39%) and an index tumor with secondary cancers greater than 0.5 cc in 82 (37%). Logistic analysis was used to predict adverse histological features. Cox proportional hazards analysis was used to predict prostate specific antigen (PSA) failure after radical prostatectomy. Results: There were no differences among the 3 groups with respect to preoperative serum PSA, number of positive cores, percent Gleason grade 4/5 cancer in the needle biopsy or histological features in radical prostatectomy specimens. On logistic analysis neither serum PSA nor pre-radical biopsy predicted adverse histological features in radical prostatectomy specimens. The Cox regression model showed that primary predictors of PSA failure were percent Gleason grade 4/5 cancer in the biopsy (HR = 2.6, p = 0.015) and prostatectomy (HR = 2.4, p = 0.04) specimens, and the number of positive cores (HR = 2.5, p = 0.04). When comparing PSA failure rates among the 3 groups, the multifocal group with smaller secondary cancers showed a better prognosis than the single tumor group (p = 0.019). Conclusions: Secondary cancers in multifocal prostate tumors did not adversely influence the results of preoperative clinical parameters, including PSA and needle biopsy findings. Percent Gleason grade 4/5 cancer in needle biopsies and prostatectomy specimens is the most powerful predictor of biochemical failure in men with stage T1c prostate cancer after radical prostatectomy.