Estrogen Receptors Expression in Lung Cancer and Breast Cancer

Lung cancer in women has been increased recently and some research found that it was not related to smoking habit. Increasing lung cancer risk in women with early onset of menopause and hormonal contraception using more than five years. Those indicated a connection of female hormon to the development of lung cancer. Estrogen is one of steroid hormon classes related to reproductive organs in female. Effect of estradiol is mediated by ER and ER. Both ER encoded by different gene, expressed to the same or different tissues in variated levels. Expression of ER was mostly observed in breast cancer cells, while ER commonly found in normal breast. The absence of ER in knock out mice showed abnormality in lungs structure development and hypoxia. ERs expression was higher in NSCLC than normal lung tissues. ER expression highly connected with tumor differentiation. ER with strong full length expression in cytoplasm and nucleus. As ER probably indicate prognosis of breast cancer, in lung cancer overexpression of ER leads to poor prognosis in postmenopausal women and also agresive tumor. Furthermore the expression of ER, ER along with EGFR mutation possibly as biomarker and prognostic markers for lung cancer as well as breast cancer.