Expression of Estrogen Receptor-α and Survival in Advanced-stage Non-small Cell Lung Cancer

Abstract

Background/aim: The favorable prognosis of women with non-small-cell lung cancer (NSCLC) compared to men might be explained by sex hormone-related mechanisms. We investigated whether this observation could be explained by the expression of estrogen receptor-alpha (ER-α) in tumor tissue.

Materials and methods: Archived, formalin fixed, paraffin embedded tumor tissue samples were retrospectively analyzed for nuclear expression of ER-α with immunohistochemistry.

Results: Biopsies from 222 patients were analyzed. Twenty-three percent were ER-α positive. Fifty-four percent of the patients were men and 46% of the tumors were adenocarcinomas. One hundred-nine (49%) patients received pemetrexed and carboplatin and 113 (51%) received gemcitabine and carboplatin. Females with ER-α positive tumors who received PC had a substantial survival benefit over all other groups (20 vs. 4.6 months; p=0.003).

Conclusion: ER-α is an independent prognostic factor in advanced NSCLC and might also be a predictive factor for response to pemetrexed/carboplatin in women.

Keywords: Prognostic factor; estrogen receptor; first-line chemotherapy; gender difference; immunohistochemistry; palliative chemotherapy; sex hormones.