The Gleason Score of Tumor at the Margin in Radical Prostatectomy is Predictive of Biochemical Recurrence

Gleason grading system is recommended by World Health Organization to grade prostate carcinoma. The Gleason score of the main tumor in prostate carcinoma is a powerful predictive factor for biochemical recurrence, but the significance of the Gleason score of tumor at the margin is unknown. In this study we aimed to investigate this subject in 336 patients (mean age 61 y, median 61, range 39 to 80; mean follow-up 41 mo, median 32, range 1 to 202) with a positive surgical margin in radical prostatectomy. The mean preoperative prostate specific antigen level was 8.2 ng/mL (median 5.8, range 0.9 to 85.0). The pathologic stage was T2, T3a, and T3b in 185, 127, and 24 patients, respectively. The Gleason score of the main tumor was 6, 7, 8, and 9 in 70 (all 3 + 3), 242 (3 + 4 in 186, 4 + 3 in 56), 8 (5 + 3 in 1, 4 + 4 in 7), and 16 (4 + 5 in 12, 5 + 4 in 4) patients, respectively. The Gleason score of the tumor at the margin was 6 in 220 (66%, all 3 + 3), 7 in 88 (26%, 3 + 4 in 59, 4 + 3 in 29), 8 in 19 (6%, all 4 + 4), 9 in 7 (2%, 4 + 5 in 4, 5 + 4 in 3), and 10 in 2 (1%) cases, respectively. The Gleason score concordance rate between the main tumor and the tumor at the margin was 69/70 (99%), 83/242 (34%), 5/8 (63%), and 6/16 (38%) in cases in which the main tumor had a Gleason score 6, 7, 8, and 9, respectively. The Gleason score of the tumor at the margin was lower, equal to, and higher than that of the main tumor in 160 (48%), 163 (49%), and 13 (4%) cases, respectively. The Gleason score of the tumor at the margin was strongly correlated with preoperative prostate-specific antigen, pathologic stage, the Gleason score of the main tumor, lymph node status, and the linear length of the tumor at the margin (P < 0.05 for all). On both univariate and multivariate analysis, the Gleason score of the tumor at the margin was a strong predictive factor for biochemical recurrence (P < 0.05). Among the patients with the same Gleason score in their main tumors (7 or above), those with a higher Gleason score of the tumor at the margin more likely had biochemical recurrence than those with a lower one. Reporting the Gleason score of the tumor at the margin can improve predictive accuracy of biochemical recurrence. We advocate reporting the Gleason score of tumor at the margin in radical prostatectomy.