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

Study Type – Therapy (individual cohort) Level of Evidence 2b What’s known on the subject? and What does the study add? Gleason score is an important clinical characteristic for treatment decisions in patients with prostate cancer. Gleason score ≤6 are generally considered low‐risk tumours with favourable clinical outcome. In this study we report long‐term data on the actual recurrence risk and survival in patients with Gleason score ≤6 tumours. We were able to demonstrate that while recurrence rates are relatively low, 18% of patients experience PSA recurrence, and 6% experience overt clinical metastases at 15‐year follow‐up. 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‐term 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.