Profile of human epidermal growth factor receptor 2 expression in epithelial ovarian carcinomas: A multicenter study from Southeast Nigeria

Abstract

Background: Human epidermal growth factor receptor 2 (HER2/neu) in epithelial ovarian cancers (EOCs) has been proposed in targeted oncological therapy as a way forward in the treatment of ovarian cancer. Currently, there is a paucity of data on the expression of HER2 in EOC in Nigeria. Objective: This study, therefore, aims to carry out an immunohistochemical study of histologically diagnosed EOC in Nnewi, Southeast Nigeria. Materials and Methods: The hematoxylin and eosin slides and formalin-fixed-paraffin-embedded tissue blocks of histologically diagnosed cases of epithelial ovarian carcinomas in the two histopathology laboratories in Nnewi, Anambra state, over a 12-year period were retrieved from the archives. Archival formalin-fixed-paraffin-embedded tissue blocks of histologically normal ovaries in these laboratories were also retrieved to serve as controls. Sections were made from the tissue blocks and stained with HER2 immunostain. Results: Fifty EOC specimens and 20 histologically normal ovaries were stained with HER2 immunostain. There was statistically significant difference in HER2 expression between normal ovaries and EOC (P = 0.016). HER2/neu- positive staining was not observed in the histologically normal ovaries. However, nine (18%) of the EOC showed HER2/neu- positive staining. HER2 positivity within EOC was independent of age (P = 0.134), tumor grade (P = 0.141), histological subtyping (P = 0.080), and molecular subtyping (P = 0.168). However, there was more HER2 positivity among those older than 50 years, low-grade carcinomas, mucinous EOC, and Type 1 EOC. Conclusion: Overall, these data support the dualistic model of ovarian carcinogenesis in Nigerian patients and therefore recommend further studies to determine the efficacy of anti-HER2/neu monoclonal antibodies in the treatment of EOC in these patients.