Expression pattern of Octamer-binding transcription factor4 in gastric cancer and its association with Ki67 and E-cadherin: a hospital-based cross-sectional study in Odisha

Abstract Background Gastric carcinoma remains a major global health burden with poor prognosis due to its biological heterogeneity and lack of reliable prognostic biomarkers. Octamer-binding transcription factor4 (OCT4), a stem cell–associated transcription factor, along with Ki67 and E-cadherin, has been implicated in tumour proliferation, invasiveness and progression. However, data on their combined expression in gastric carcinoma from eastern India are limited. Objectives To evaluate the immunohistochemical expression of OCT4 in gastric carcinoma and assess its association with tumour proliferation (Ki67), tumour invasiveness (E-cadherin) and clinicopathological parameters in a tertiary care centre in Odisha. Materials and methods This hospital-based prospective study included 94 histologically confirmed gastric adenocarcinoma cases over a period of two years. Immunohistochemistry for OCT4, Ki67 and E-cadherin was performed on all the resected samples of total of 94 cases. OCT4 expression was assessed using immunoreactivity score, with clinicopathological variables were analysed in all the cases using appropriate statistical tests and correlation analysis. Results The mean age was 57.4 years with male predominance. Tubular type adenocarcinoma was the most common subtype, followed by poorly cohesive type. Poorly cohesive type showed high OCT4 expression (96.7%, n = 29), high Ki67 indices and abnormal E-cadherin expression (93.3%, n = 28). OCT4 demonstrated a strong positive correlation with Ki67 ( r = 0.72) and tumour grade ( r = 0.81) and moderate correlation with lymph node status, lymphovascular and perineural invasion. E-cadherin showed an inverse correlation with OCT4, Ki67, tumour grade and nodal metastasis, suggesting epithelial–mesenchymal transition–associated aggressiveness. Conclusion Combined assessment of OCT4, Ki67 and E-cadherin provides valuable insights into tumour biology and may aid individualized management of gastric carcinoma. Further prospective studies are warranted to validate their clinical utility.