Differences in histopathological and biochemical outcomes in patients with low Gleason score prostate cancer.

Abstract

Diagnosis (case series). 4. To test whether the number or percentage of positive biopsy cores can be used to discriminate between patients with prostate cancer of a favourable and less favourable Gleason score (GS) < or =3 + 3, as prognostically, not all GS 3 + 3 prostate cancers are the same. In all, 1106 consecutive patients with a prostate-specific antigen (PSA) level of < or =10 ng/mL and a biopsy GS of < or =3 + 3 or 3 + 4 had an open radical prostatectomy. The number of positive biopsy cores (< or =2 vs > or =3) were stratified into low- vs high-risk groups. Subsequently, we stratified patients according to the GS and the percentage of positive biopsy cores (<50% vs > or =50%). The pathological stage and the 5-year biochemical recurrence (BCR)-free survival rates were examined in univariable and multivariable models. Based on the number of positive cores, the rate of extraprostatic disease was 11.7% and 23.3%, respectively, in the low-and high-risk GS < or =3 + 3 groups (P < 0.001). The 5-year BCR-free survival rates were 95.0%, 77.8%, 81.2% and 66.5% for, respectively, low- and high-risk GS < or =3 + 3 and for low- and high-risk GS 3 + 4 patients. Univariable and multivariable intergroup BCR rate differences were statistically significant between low- vs high-risk GS 3 + 3 patients (P < 0.001), but not significant between high-risk GS < or =3 + 3 vs low-risk GS 3 + 4 patients (P = 0.6). Comparable results were obtained when comparisons were made according to the percentage of positive biopsy cores. Our results corroborate the finding that not all patients with a biopsy GS of < or =3 + 3 prostate cancer have low-risk disease. High-risk GS < or =3 + 3 patients have a similar risk profile as more favourable GS 3 + 4 patients. This finding warrants consideration when deciding on treatment.