Estrogen and progesterone receptor expression in endometrial cancer: a narrative review of global and Nigerian immunohistochemical evidence

Abstract Endometrial carcinoma (EC) is one of the most common gynaecological malignancies worldwide, and its pathogenesis is closely linked to hormonal signalling. Estrogen receptor (ER) and progesterone receptor (PR) expression are commonly assessed in both clinical and research settings and provide useful prognostic and therapeutic information, particularly in endometrioid tumours. This narrative review synthesises global and Nigerian evidence on ER and PR expression in EC, with emphasis on immunohistochemical findings derived from formalin-fixed, paraffin-embedded tissues. Relevant literature was identified through targeted searches of PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar, with additional articles identified through reference screening. Across globally reviewed studies, ER and PR expression is most observed in well-differentiated endometrioid carcinomas. It is generally associated with lower tumour grade, earlier stage, and more favourable clinical outcomes. In contrast, reduced or absent receptor expression is more frequently reported in high-grade tumours and non-endometrioid subtypes, which are typically associated with more aggressive biological behaviour and poorer response to hormonal therapy. Limited Nigerian studies suggest lower ER and PR positivity rates than those reported in many international series; however, these findings are based on small, retrospective, hospital-based cohorts and should be regarded as preliminary and hypothesis-generating. ER and PR assessment remains a clinically useful component of EC evaluation, particularly in resource-limited settings where access to advanced molecular classification may be restricted. Greater standardisation of immunohistochemical methods and reporting, together with larger multicentre studies, may improve comparability across populations and support broader integration of hormone receptor assessment into routine clinical practice.