Abstract 792: Prognostic significance of four molecular markers in relation to fatal prostate cancer after prostatectomy

Aside from Gleason grade, there are no established biomarkers to differentiate aggressive from indolent disease in early-stage prostate cancer. Such markers are needed to stratify patient selection for radical or conservative treatment. In the population of three managed care organizations, we conducted a case-control study to evaluate the predictive value of immunohistochemical expression of four molecular markers in formalin-fixed paraffin-embedded tumor tissue from prostatectomy specimens. Cases included 286 men whose prostate cancers progressed to death between 1971 and 2001; 344 controls with non-fatal prostate cancer were closely matched to cases on age, race, tumor stage, diagnosis year, and patterns of health plan membership. One expert prostate cancer pathologist reviewed all pathology slides to determine Gleason grade and select the highest grade tumor specimen for analysis. Formalin-fixed paraffin embedded tissue sections from the above specimens were immunostained by an automated method using antibodies against Ki-67, p53, p27kip1 and BCl-2. Immunoreactivity was semi-quantitatively scored based on intensity and percentage of positive cells in both tumor and adjacent benign tissue, and results were correlated with clinicopathologic variables. Using unconditional logistic regression analysis, we identified Ki-67, P53, P27kip1, and BCl-2 as statistically significant predictors of prostate cancer mortality after adjustment for age, group, race, health plan, diagnosis year, and tumor stage. Marker expression was classified as presence yes/no (P53, BCl-2) or absence yes/no (P27kip1) of any staining or 10%+ expression vs. less (Ki-67). After further adjustment for Gleason grade, marker associations with mortality were as follows: Ki-67 odds ratio = 12.3, 95% confidence interval (CI) 5.3-28.3, p Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 792.