Long-term outcome in patients with a Gleason score ≤6 prostate cancer treated by radical prostatectomy

OBJECTIVE To determine the actual recurrence risk of patients with a Gleason score (GS) <= 6 treated with radical retropubic prostatectomy (RRP) and bilateral lymphadenectomy in a cohort with long-erm follow-up. PATIENTS AND METHODS The USC/Norris Comprehensive Cancer Center database included 3235 consecutive patients who underwent RRP for prostate cancer between January 1972 and December 2005. We identified 1383 patients with a GS <= 6 in prostatectomy specimens. Median follow-up was 8.3 years. Data on pathological and clinical characteristics and outcome were prospectively recorded. Statistical analysis was performed using the stratified log-rank test and stepwise Cox regression analysis. RESULTS A GS of 6 was present in 66%, 5 in 27%, 4 in 5% and 3 or 2 in 3% of cases. Tumour classification was pT2N0 (83%), pT3N0 (14%), pT4N0 (0.1%) and any TN1 (2%). Positive margins were seen in 18%. Estimated PSA and clinical recurrence rate were 14% and 4% after 10 years and 18% and 6% after 15 years, respectively. In multivariate analysis, N-stage (P < 0.001), T-stage (P = 0.02) and margin status (P < 0.001) were associated with PSA recurrence. N-stage (P < 0.001) and T-stage (P = 0.01) were associated with clinical recurrence. Overall, patients with a GS = 6 accounted for 26% of all PSA recurrences and for 20% of all patients with clinical recurrences in the database. CONCLUSION A relatively small proportion of patients with a GS <= 6 cancer developed PSA recurrence and/or overt metastasis. However, these patients account for a substantial minority of those who experienced recurrence and metastasis.