Prostate Carcinoma Grade and Length But Not Cribriform Architecture at Positive Surgical Margins Are Predictive for Biochemical Recurrence After Radical Prostatectomy

Postoperative biochemical recurrence occurs in up to 40% of prostate carcinoma patients treated with radical prostatectomy. Primary tumor grade and cribriform architecture are important parameters for clinical outcome; however, their relevance at positive surgical margins has not been completely elucidated yet. We reviewed 835 radical prostatectomy specimens and recorded pT-stage, surgical margin status, Grade Group, and cribriform architecture of the primary tumor and at positive surgical margins. Clinicopathologic parameters and biochemical recurrence-free survival (BCRFS) were used as endpoints. Positive surgical margins were present in 284 (34%) patients, with a median cumulative length of 5.0 mm. In 46%, the Grade Group at the margin was equal to the primary tumor grade, while being lower in 42% and higher in 12%. In multivariable analysis, Grade Group at the margin outperformed the Grade Group of the primary tumor in predicting BCRFS. Among primary Grade Group 2 patients, 56% had Grade Group 1 disease at the margin. Multivariable analysis identified cumulative length, Grade Group at the margin, and lymph node metastasis as independent predictors for BCRFS, while percentage Gleason pattern 4, tertiary Gleason pattern 5 of the primary tumor, and cribriform architecture at the margin were not. In conclusion, the Grade Group at the positive surgical margin was dissimilar to the primary tumor grade in 54% and better predicted BCRFS than the primary tumor grade. Cumulative length and tumor grade at the margin were independent predictors for BCRFS, whereas cribriform architecture at the margin was not.