Immunohistochemical Expression of ER, PR and HER2/neu in Endometrial Carcinoma

Abstract

Endometrial carcinoma (EC) is the third common gynecologic cancer in India. It consists of two major histological types: the most common endometrioid or type I EC and non-endometrioid or type II EC. They are biologically distinct, and various markers have been proposed as prognostic biomarkers in EC besides clinical and pathological features. To study the immunohistochemical (IHC) expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor (HER2/neu) in EC and to correlate them with various clinicopathological parameters. IHC study of ER, PR and HER2/neu was performed on 35 cases of histopathologically diagnosed EC in hysterectomy specimens for a period of 4 years from 2014 to 2017. Majority of the patients were aged 51–60 years, and the common comorbid conditions were type 2 diabetes mellitus, hypertension and obesity. Histologically, 31 (88.57%) cases were of type 1 EC and 4 (11.43%) were of type II EC; in type II EC, 2 (5.7%) cases were papillary serous carcinoma and the remaining two cases each were malignant mixed Mullerian tumor (MMMT) and dedifferentiated carcinoma (DC). ER expression was observed in 29 cases (82.9%) and was statistically significant with tumor stage, tumor grade, histological type and intraglandular necrosis. PR expression was seen in 22 (62.9%) cases and showed significant association with tumor grade, myometrial invasion and histological type. HER2/neu was expressed in one case. Establishing the diagnosis of molecular subtype of EC with limited markers, namely ER/PR, HER2/neu expression similar to breast cancer, may be useful to determine the treatment and prognosis, especially in developing countries. Studies with larger sample sizes may elucidate their role, which was the limitation in this study.