Total Positive Margin Length as a Novel Prognostic Indicator After Radical Prostatectomy

Objectives: Positive surgical margins (PSMs) are associated with biochemical recurrence (BCR) following radical prostatectomy (RP). However, their prognostic significance varies, and not all patients with PSMs experience recurrence. This study aimed to evaluate whether detailed analysis of margin characteristics could improve postoperative risk stratification. Methods: We retrospectively reviewed 1003 patients who underwent RP without neoadjuvant or adjuvant therapy. PSMs were categorized according to total PSM length (≤ 5 mm vs. > 5 mm), maximum PSM length (≥ 3 mm vs. < 3 mm), primary Gleason pattern (pGP) at PSM (pGP3 vs. pGP4–5), multifocality (single vs. multiple), and location (apex-only vs. others). Other pathological factors analyzed pathological T/N stage, ISUP grade group, and intraductal carcinoma of the prostate (IDC-P). Results: PSMs were present in 377 patients (37%), Total PSM length was 5.0 (0.1–66) mm and pGP3 was more common in apex-only PSMs. pGS, IDC-P, and PSM status were significant predictors of BCR in the entire cohort. Among margin parameters, total PSM length and pGP at the PSM were the strongest predictors. In organ-confined disease with PSM, BCR risk was significantly stratified into three groups based on total PSM length > 5 mm and pGP4–5 at the margin (0, 1, or 2; p < 0.001). Conclusions: A risk classification incorporating total PSM length and pGP at the margin improves postoperative prognostic stratification for localized prostate cancer with PSMs. In cases with multiple PSMs, total PSM length may be more informative than the maximum PSM length European Association of Urology recommended.