Introduction
Why esophageal adenocarcinoma occurs approximately 8 times less often in women than men is not well understood. One possiblity is that estrogen and its receptors play a role. This study investigated and compared expression levels, cellular distribution and localization of estrogen receptors (ERα and ERβ) in esophageal adenocarcinoma in tissues from men and women.
Methods
Paraffin embedded esophageal mucosal samples were obtained from 53 patients (25 females and 28 males) with esophageal adenocarcinoma. Tissues were stained for ERα and ERβ using peroxidase-based immunohistochemistry and staining was visualised with brightfield microscopy. Cancer tissues were scored separately for ERα and ERβ, and the degree of ERα and ERβ presence in nuclear and/or cytoplasmic cell regions was quantified. Clinicopathological data were also collected and included: age, tumor location, treatment, TNM stage and survival. Associations between clinicopathological parameters and levels of ER expression were determined.
Results
ERα and ERβ were detected in esophageal adenocarcinoma tissues and were present in the cytoplasm and the nucleus. 39 (73.6%) patients had nuclear expression of ERβ in less than 10 % of cancer cells. The nuclear expression of ERβ was significantly higher in females than in males (P =0.0343). No significant difference between males and females was detected for expression level of ERa, however the higher expression of ERα was significantly associated with the presence of lymph node metastasis in females (P = 0.0298). A poorer response to chemo-radiotherapy was also associated with higher expression of ERα (P = 0.0373) in both sexes.
Conclusions
Significant gender-linked differences in expression and localisation of ERβ in esophageal adenocarcinoma were identified. Correlations between some prognostic parameters and estrogen receptor expression levels were seen. Further exploration of estrogen signaling in the development of esophageal adenocarcinoma is warranted using a larger cohort of patients.