Prostate cancer stage shift has eliminated the gap in disease-free survival in black and white American men after radical prostatectomy

Abstract

Purpose: The initiation of prostate specific antigen (PSA) testing has led to increased public awareness, early detection and a stage shift in prostate cancer. We have previously reported that black American men have worse disease-free survival independently of pathological or clinical factors. We tested the stage shift effects on disease-free survival in our cohort of patients treated with radical prostatectomy.

Materials and methods: A total of 1,042 consecutive patients underwent radical prostatectomy performed by Wayne State University full-time faculty. The cohort was divided by the year of surgery as before (585 men in group 1) or after (457 in group 2) 1996. Clinicopathological and disease-free survival data were obtained from the Karmanos Cancer Institute multidisciplinary prostate cancer database.

Results: Improvements in clinical stage, preoperative PSA and biopsy Gleason score were observed in group 2 (p = 0.0001). Pathological organ confined disease increased in group 2 versus 1 in the 2 races, including 89 of 153 (58%) from 66 of 178 (37%) in black men and 189 of 304 (62%) from 194 of 407 (48%) in white men (p = 0.003 and 0.001, respectively). Calculated cancer recurrence-free median probability in group 1 at 42 months was 81% and 68% in white and black men, respectively (log rank test p = 0.001). These differences became insignificant in group 2 patients at 42 months with a median probability of 90% and 88% in white and black men, respectively (log rank test p = 0.39), representing a net increase in disease-free survival of 20% in black men. Specimen Gleason score, PSA and pathological stage were independent predictors of survival in the 2 groups. In contrast, race was an independent predictor only in group 1.

Conclusions: The increased rate of pathological organ confined disease is translating into improved disease-free survival rates. These early data suggest that the survival gap in black and white American men is narrowing and may become statistically insignificant.