Endometrial Carcinoma in Kenya: Clinical and Biomarker Profiles of 123 Cases Seen at Two Tertiary Referral Centers Authors

Olivia Chesikaw^1*Allan Njau¹Erick Chesori²Khadija Warfa¹Anisa Mburu³Shaffi Afrin Fatima²Natalie Banet⁴Jonathan Wawire¹

• ¹Aga Khan University (Kenya), Nairobi, Kenya
• ²Moi Teaching and Referral Hospital (MTRH), Eldoret, Kenya
• ³The Aga Khan Hospital, Mombasa, Kenya
• ⁴Cleveland Clinic, Cleveland, Ohio, United States

Endometrial carcinoma (EC) is the second-most common gynecologic malignancy globally after cervical cancer, with varying incidence and outcomes across diHerent populations. It comprises a heterogeneous group of tumors with distinct histopathologic and molecular characteristics. This study aims to provide a comprehensive clinicopathologic characterization of EC in the Kenyan population, focusing on histologic types and immunohistochemical biomarker expression. This retrospective study was conducted on archival tissue blocks from 123 patients diagnosed with EC at two major referral hospitals in Kenya. A tissue microarray block was constructed, and immunohistochemistry for 11 biomarkers, including ER, PR, p16, p53, NapsinA, ARID1A, PTEN, and Mismatch repair (MMR) proteins, was performed. Data analysis included descriptive statistics with Fisher's exact test performed to compare proportions, while diHerences in means were compared using the Mann-Whitney U-test, with p <0.05 considered significant. The median age at diagnosis was 63 years, with the most common histologic type being endometrioid carcinoma (55.2%), followed by serous carcinoma (26%). Most low FIGO-stage patients had low-grade endometrioid histology. Obesity was the most frequently reported risk factor. Though hormone receptor biomarkers and p16 showed heterogeneous staining across all histologic types, ER and PR showed more frequent strong expression associated with endometrioid histology, while strong diHuse p16 staining was observed more frequently in serous carcinoma. MMR protein loss was predominantly observed in endometrioid carcinoma (30.0%), while all cases of serous carcinoma showed aberrant p53 expression. Abnormal p53 expression was also observed in 53.5% of all ECs, pointing to a higher percentage of patients with poor prognostic factors. These findings provide valuable insights into the landscape of EC in a Kenyan population, emphasizing the role of IHC in the diagnosis and potential tailored therapeutic strategies for management in the region, where access to molecular testing may be limited.