Abstract 903: Expression of estrogen receptor beta together with aromatase predicts survival in non-small cell lung cancer

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Lung cancer continues to be the leading cause of cancer mortality. There is increasing evidence suggesting estrogens and estrogen signaling play a significant role in lung cancer pathophysiology. Estrogen receptors (ER) alpha and beta are expressed in normal lung and many non-small cell lung cancers. Previously we found that in women 65 years and older with non-small cell lung cancer (NSCLC), higher aromatase levels in tumor cells conferred a worse prognosis for survival. Here we examine whether ER alpha and ER beta levels in conjunction with aromatase can further define different patient groups with respect to survival outcomes and possible treatment regimens. Methods: Immunohistochemistry was performed on a high-density tissue microarray with marker data and clinical information available for 378 patients. Patients were subcategorized by gender, age, smoking status and tumor histology. Survival data was determined using the Cox proportional hazards model and Kaplan-Meier curves. Results: Unlike aromatase, neither ER alpha nor ER beta alone were predictors of survival in NSCLC patients or any subset of these patients examined. However, when coupled with aromatase expression, higher ER beta levels predicted poorer survival in those patients whose tumors expressed higher levels of aromatase. Although this survival difference was present in patients of both genders, it was more pronounced in women > 65 years old, where higher expression of both ER beta and aromatase showed a markedly worse survival rate than that determined by aromatase alone. Conclusion: Combined expression of ER beta with aromatase has predictive value for survival in different gender and age subgroups of NSCLC patients. This predictive value is stronger than each individual marker alone. These results suggest that possibly treatment with aromatase inhibitors alone or combined with estrogen receptor modulators may have benefit in some subpopulations of NSCLC patients. 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 903. doi:10.1158/1538-7445.AM2011-903