Utility of ER, p53, CEA and Napsin A in Histological Subtyping of Endometrial Carcinoma and Their Correlation with Clinicopathological Prognostic Parameters: Experience from a Referral Institute.

Background & objective: Endometrial Carcinoma (EC) is the most common gynecological cancer with a global incidence of 23.2 per 1 lakh population. Histological subclassification of EC is extremely crucial for the diagnosis, proper management strategies, and prognosis. This study was conducted in a tertiary care institute to analyze the expression pattern of a minimum panel of 4 markers (ER, p53, CEA, Napsin A) with emphasis on their utility in the routine histological subtyping, aberrant expression, and correlation with various clinicopathological parameters.

Methods: A time-bound cross-sectional observational and analytical study was conducted, which includes cases diagnosed in our laboratory from January 2016 to April 2021.

Results: Sixty cases diagnosed as EC during the study period formed the sample cases. The ER was expressed in 85% (53/60) of cases in the current study. Among them, 94% (50/53) were endometrioid endometrial carcinomas (EECs). A negative correlation was found between ER intensity and age (r= -1.48). Of 60 EC cases, 10 (16%) cases expressed p53. The tumors positive for p53 with higher intensity were negative for ER and vice versa. The expression pattern of ER and p53 was statistically significant (P=-0.021). On IHC, 84.6% (11/13) of CEA-positive cases expressed both ER and CEA, suggesting mucinous differentiation. Napsin A was expressed in two cases of EEC, FIGO grade I, and one case of serous carcinoma.

Conclusion: An inverse association was found between ER and p53 expression. The CEA is valuable in identifying EEC with mucinous differentiation.