Abstract INTRODUCTION: Urothelial carcinoma of the bladder develops through multiple cellular alterations. Traditional single-marker and multimarker molecular profiling approaches in bladder cancer do not account for risk factors and their influence on clinical outcome. Cigarette smoking is the most well established risk factor for bladder cancer in the western world. This study sought to examine the prognostic value of molecular alterations across all disease stages after stratifying for clinicopathologic factors and smoking in a population-based cohort. METHODS: 212 patients from the Los Angeles County Cancer Surveillance Program, a NCI/SEER cancer registry, were included. To analyze the biologic and molecular impact of smoking, we introduced a novel “smoking intensity” variable that took into account a patient's smoking status, duration of smoking and number of cigarettes smoked daily to quantify the impact of exposure to cigarette smoke. Primary bladder tumors were immunohistochemically profiled for Bax, caspase-3, Apaf-1, Bcl-2, p53, p21, cyclooxygenase-2, vascular endothelial growth factor, and E-cadherin alterations. Univariate analyses and multivariable modeling were used to examine associations with outcome. RESULTS: Median follow up was 13.2 years. For smokers (n=184), median age to start smoking was 17 years (range, 12-40 years), and median smoking duration was 35 years (range, 0.5-50 years). Median number of cigarettes smoked daily was 25 (range, 2-100). Increasing pathologic stage and smoking intensity were independently associated with worsening survival (P<0.001). p53, E-cadherin, p21 and Apaf-1 expressions were significantly associated with pathologic stage. E-cadherin and p53 were univariately prognostic for outcome (P=0.014 and P=0.032, respectively), and remained predictive after stratifying by smoking intensity. Apaf-1 was the most valuable individual marker, being prognostic univariately (P=0.005), and after stratification by stage (P=0.029), smoking (P=0.030), and both stage and smoking combined (P=0.025). Multivariable modeling confirmed this significance in association. When analyzed in combination, alterations in all nine biomarkers were significantly prognostic for survival by univariate and multivariate stratification. CONCLUSION: The study confirms detrimental effects of smoking on bladder cancer prognosis. Apaf-1, E-cadherin and p53 can individually predict survival in bladder cancer patients, with Apaf-1 being the most prognostic individual marker. The nine-biomarker panel can significantly predict outcome independent of stage and smoking history. Increasing biomarker alterations was significantly associated with worsening survival, although markers comprising the panel were not necessarily prognostic individually. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2258. doi:10.1158/1538-7445.AM2011-2258