The elevated level of ERα36 is correlated with nodal metastasis and poor prognosis in lung adenocarcinoma

Abstract

Introduction: ERα36 is a recently cloned variant of estrogen receptor-alpha which has been proved to play an active role in a series of malignant diseases.

Method: ERα36 expression was examined using immunohistochemical methods with sections from 126 resected NSCLC specimens. The immunoreactivity of ERα66 was also studied as a comparison. Kaplan-Meier method and multivariable Cox proportional hazards regression analyses were used to examine the relationship between ERα36 and survival.

Result: ERα36 was more highly expressed in NSCLC patients compared to ERα66. ERα36 expression has a strong correlation with histology (AC: 53/70, SCC: 16/56, P<0.000) and had a significantly positive correlation with lymphatic metastasis (P=0.014) in adenocarcinoma. High ERα36 expression was correlated with poorer overall survival (OS) (P=0.020) and disease-free survival (DFS) (P=0.024) in adenocarcinoma. Furthermore, ERα36 status was a significant independent prognostic factor of OS (P=0.018, HR: 3.142, 95% CI: 1.215-8.128) and DFS (P=0.024, HR: 2.720, 95% CI: 1.141-6.486) in lung adenocarcinoma patients.

Conclusion: ERα36 had a high expression mainly in adenocarcinoma and the high expression of ERα36 was strongly correlated with more advanced regional lymph node metastasis and poor survival in lung adenocarcinoma.

Keywords: Estrogen receptor alpha36; Estrogen receptor alpha66; Non-small cell lung cancer; Prognosis.