The Gleason score is an important parameter for clinical outcome in prostate 
cancer patients. Gleason score 8 is a heterogeneous disease including Gleason 
score 3 + 5, 4 + 4, and 5 + 3 tumors, and encompasses a broad range of tumor 
growth patterns. Our objective was to characterize individual growth patterns 
and identify prognostic parameters in Gleason score 8 prostate cancer patients. 
We reviewed 1064 radical prostatectomy specimens, recorded individual Gleason 4 
and 5 growth patterns as well as presence of intraductal carcinoma, and 
evaluated biochemical recurrence- and metastasis-free survival. Gleason score 8 
disease was identified in 140 (13%) patients, of whom 76 (54%) had Gleason score 
3 + 5, 46 (33%) 4 + 4, and 18 (13%) 5 + 3 disease. Invasive cribriform and/or 
intraductal carcinoma (n = 87, 62%) was observed more frequently in Gleason 
score 4 + 4 (93%) than 3 + 5 (47%; P < 0.001) and 5 + 3 (44%; P < 0.001) 
patients. Gleason pattern 5 was present in 110 (79%) men: as single cells and/or 
cords in 99 (90%) and solid fields in 32 (29%) cases. Solid field pattern 5 
coexisted with cribriform architecture (23/32, 72%) more frequently than 
nonsolid pattern 5 cases (36/78, 46%, P = 0.02). In multivariable analysis 
including age, prostate-specific antigen, pT-stage, surgical margin status, and 
lymph node metastases, presence of cribriform architecture was an independent 
parameter for biochemical recurrence-free (hazard ratio (HR) 2.0, 95% confidence 
interval (CI) 1.0-3.7; P = 0.04) and metastasis-free (HR 3.5, 95% CI 1.0-12.3; 
P = 0.05) survival. In conclusion, invasive cribriform and/or intraductal 
carcinoma occurs more frequently in Gleason score 4 + 4 prostate cancer patients 
than in Gleason score 3 + 5 and 5 + 3, and is an independent parameter for 
biochemical recurrence and metastasis. Therefore, cribriform architecture has 
added value in risk stratification of Gleason score 8 prostate cancer patients.