Presence of invasive cribriform or intraductal growth at biopsy outperforms percentage grade 4 in predicting outcome of Gleason score 3+4=7 prostate cancer.

Abstract

Relative increase of grade 4 and presence of invasive cribriform and/or intraductal carcinoma have individually been associated with adverse outcome of Gleason score 7 (GS 7) prostate cancer. The objective of this study was to investigate the relation of Gleason grade 4 tumor percentage (%GG4) and invasive cribriform and/or intraductal carcinoma in GS 3+4=7 prostate cancer biopsies. We reviewed 1031 prostate cancer biopsies from the European Randomized Study of Screening for Prostate Cancer. In total 370 men had G3+4=7. The relation of invasive cribriform and/or intraductal carcinoma and %GG4 with biochemical recurrence-free survival (BCRFS) after radical prostatectomy (n=146) and radiation therapy (n=195) was analyzed using Cox regression. Invasive cribriform and/or intraductal carcinoma occurred in 7/121 (6%) patients with 1-10% GG4, 29/131 (22%) with 10-25%, and 52/118 (44%) with 25-50% GG4 (P<0.001). In crude analysis, both invasive cribriform and/or intraductal carcinoma (HR 2.72; 95% CI: 1.33-5.95; P=0.006) and 10-50% GG4 (HR 2.43; 95% CI: 1.10-5.37; P=0.03) were associated with BCRFS after prostatectomy. In adjusted analysis, invasive cribriform and/or intraductal carcinoma was an independent predictor for BCRFS (HR 2.40; 95% CI: 1.03-5.60; P=0.04) after prostatectomy, whereas percentage %GG4 (HR 1.00; 95% CI: 0.97-1.03; P=0.80) was not. While invasive cribriform and/or intraductal carcinoma (HR 2.58; 95% CI: 1.59-4.21; P<0.001) performed better than 10-50% GG4 (HR 1.24; 95% CI: 0.67-2.29; P=0.49) for prediction of BCRFS after radiation therapy, both parameters were insignificant in analysis adjusted for prostate-specific antigen (P=0.001), positive biopsies (P<0.001) and tumor volume (P=0.05). In conclusion, increased %GG4 is associated with invasive cribriform and/or intraductal carcinoma in GS 3+4=7 prostate cancer biopsies. Invasive cribriform and/or intraductal carcinoma is an independent parameter for BCR after prostatectomy, whereas %GG4 is not. The presence of invasive cribriform and/or intraductal carcinoma has to be included in pathology reports and should act as exclusion criterion for active surveillance.