Estrogen receptor α and β in esophageal squamous cell carcinoma

A gender difference has been reported in the morbidity of esophageal squamous cell carcinoma (ESCC). Estrogens have been proposed to play a role in this difference but the details have not yet been clarified. Therefore, in the present study, we examined the status of estrogen receptor (ER)a and ER beta in 90 Japanese ESCC patients. ERa and ER beta immunoreactivity was detected in the nuclei of ESCC cells (41.1 and 97.8%, respectively). There was a significant positive association between the ER beta H score and histological differentiation ( P=0.0403), TNM-pM (LYM) (P similar to= 0.00164) and Ki67/MIB1 LI of carcinoma cells (P=0.0497, r=0.207). In addition, the ER beta status of carcinoma cells was significantly correlated with unfavorable clinical outcome of the patients. Multivariate analysis further revealed the ER beta status in carcinoma cells as an independent unfavorable prognostic factor of these patients. We further examined the effects of estrogen treatment on ESCC cell line (ECGI-10) transfected with ERa or ER beta in vitro. The number of ECGI-10 transfected with ER beta was increased by estradiol or ER beta specific agonist but estradiol did not exert any effect upon the cell number of ECGI-10 transfected with ERa. In summary, the results of the present study clearly demonstrate that the status of ER beta in ESCC was closely associated with the unfavorable prognosis, possibly through altering cell proliferation of carcinoma cells. (Cancer Sci 2012; 103: 13481355)