Pathological T2 sub-divisions as a prognostic factor in the biochemical recurrence of prostate cancer

OBJECTIVE To determine the adequacy of T2 prostate cancer (PCa) sub-staging as an independent Predictor of biochemical disease-free survival (bDFS) after radical prostatectomy. MATERIALS AND METHODS The Duke Prostate Center database was queried for patients who underwent radical prostatectomy between 1988 and 2007 and had pT2 PCa, identifying 1990 cases. Prostate-specific antigen (PSA) recurrence was defined as a single value ≥0.2 ng/mL. Kaplan-Meier curves compared differences in bDFS between T2 sub-divisions. Multivariate analysis was performed, adjusting for age, pathological Gleason sum, surgical margin status, preoperative PSA, race, total tumour percentage and prostate weight on biochemical recurrence. RESULTS The mean age at surgery was 62 years, and 16% of patients were African-American. Median prostate weight was 40 g [interquartile range (IQR) 31-52] and median preoperative PSA was 5.6 (IQR 4.2-7.8). Pathological Gleason score was ≤6 in 57%, 7 in 38%, and ≥8 in 5%; pathological T stage distribution was 18% T2a, 6% T2b, and 76% T2c; and percentage tumour involvement was ≤5% in 43%, between 5.1 and 10% in 24%, between 10.1 and 15% in 10%, and >15% in 19%. 366 (18.4%) patients had a biochemical recurrence after a median of 4.6 years (IQR 2.1-8.2) follow-up. bDFS was significantly (P= 0.006) higher for pT2a disease than for pT2b and pT2c, which were comparable. Adjusting for demographic and other pathological variables, T2 sub-divisions lost statistical significance. CONCLUSIONS Pathological T2a prostate cancer has significantly higher bDFS than the pT2b or pT2c sub-groups in univariate but not multivariate analyses. Different pathological features should be explored to create more meaningfully predictive pathological T2 sub-divisions.