Significance of the cribriform morphology area ratio for biochemical recurrence in Gleason score 4 + 4 prostate cancer patients following robot‐assisted radical prostatectomy

Abstract Background In prostate cancer, histological cribriform patterns are categorized as Gleason pattern 4, and recent studies have indicated that their size and percentage are associated with the risk of biochemical recurrence (BCR). However, these studies included a mixture of cases with various Gleason scores (GSs). We therefore examined the prognostic value of the area and percentage of cribriform patterns in patients with GS 4 + 4 prostate cancer. Methods We investigated 108 patients with GS 4 + 4 prostate cancer who underwent robot‐assisted radical prostatectomy (RARP). After digitally scanning the hematoxylin and eosin‐stained slides, we measured the area of the entire cancer and cribriform patterns. Predictive factors for BCR were explored using log‐rank test and Cox proportional hazard model analyses. Results Sixty‐seven (62.0%) patients had a cribriform pattern in RARP specimens, and 32 (29.6%) experienced BCR. The median total cancer area, cribriform pattern area, and percentage of cribriform pattern area (% cribriform) were 427.70 mm 2 (interquartile range IQR, 171.65–688.53 mm 2 ), 8.85 mm 2 (IQR, 0–98.83 mm 2 ), and 2.44% (IQR, 0%–33.70%), respectively. Univariate analyses showed that higher preoperative serum prostate‐specific antigen (PSA) levels, positive resection margins, advanced pathological T stage, extraprostatic extension, larger total cancer area, larger cribriform morphology area, and higher % cribriform values were significantly associated with BCR. A multivariate analysis demonstrated that the PSA level (hazard ratio HR, 1.061; 95% confidence interval CI, 1.011–1.113; p = 0.017) and % cribriform (HR, 1.018; 95% CI, 1.005–1.031; p = 0.005) were independent predictors of BCR. Conclusions An increased % cribriform value was associated with BCR in patients with GS 4 + 4 prostate cancer following RARP.