The GP Score, a Simplified Formula (Bioptic Gleason Score Times Prostate Specific Antigen) as a Predictor for Biochemical Failure after Prostatectomy in Prostate Cancer

OBJECTIVES: We used a new GP score (Gleason score multiplied by prostate-specific antigen) without the T stage as a predictive value for biochemical failure (BCF) after prostatectomy. MATERIALS AND METHODS: We assessed 459 prostate cancer patients who underwent prostatectomies at our institution. Three sub-groups were defined in terms of D'Amico classification risk (low, intermediate, and high) and Gleason score (low, < 50; intermediate, 50-100; and high GP score, > 100). Risk factors for BCF were evaluated by multivariate analysis with a Cox hazard model. A log-rank test was used to compare the BCF rate in the 2 groups. RESULTS: There was nosignificant difference in the non-BCF rate between the lowrisk and low GP score subgroups or the intermediate risk andintermediate GP score subgroups. In contrast, the non-BCFrate of the high GP score subgroup (42.1%) was significantlylower than that of the high-risk subgroup (66.1%, log-rankp = 0.008). Based on multivariate analysis, a high GP score(p = 0.001; HR 3.78; 95%CI 1.95-7.35) was a significant independent risk factor for BCF after prostatectomy. CONCLUSION: The GP score, consisting of two absolute numbers, may be a valuable predictive factor for BCF after prostatectomy, especially in the high-risk failure group.