Prognostic Factors for Multifocal Prostate Cancer in Radical Prostatectomy Specimens: Lack of Significance of Secondary Cancers

Abstract

We evaluated secondary cancers in the prostate in relation to predictions of pathological stage and prognosis. 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. 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). 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.