CONCORDANCE BETWEEN IMMUNOHISTOCHEMISTRY AND RT-qPCR FOR MOLECULAR TYPING OF FEMALE BREAST CANCER IN BOUAKE

Background: Immunohistochemistry is a technique commonly used in the diagnosis of breast cancer. It is performed on histological preparations, following conventional histological examination. This lengthens the time it takes for patients to receive their results. RT-qPCR has been proposed as an alternative for shorter turnaround times compatible with early management. Objective: In the present study the aim was to determine the concordance rate between immunohistochemistry and RT-qPCR analyses on fresh biopsy samples from breast cancer patients in Bouaké. Methods: Studies on this subject have analyzed frozen paraffin blocks. This prospective descriptive cross-sectional study analyzed the expression of estrogen receptor α (ER1), progesterone receptor (PR) and human epidermal growth factor β (HER2) genes by immunohistochemistry and RT-qPCR. It took place over a 16-month period (September 2023-January 2025). Patients came from the 5 diagnostic and management centers for breast pathologies in the Gbêkê region. Results: The mean age was 43.8 ± 11.0 years, with extremes of 24 and 71 years. More than two-thirds of patients (69.8%) had hormone-sensitive cancer, with a preponderance of luminal A (44.2%) followed by luminal B (25.6%). The estrogen receptor gene (ER1) was overexpressed in 44.2% of carcinogenic breast biopsies. PR and HER2 genes expression was elevated in 53.5% and 34.9% of cases respectively. Cohen's κ coefficient of concordance between IHC and RT-qPCR was 0.86, 0.64 and 0.79 for ER1, PR and HER2 respectively. Conclusion : Determining gene expression by RT-qPCR on fresh biopsies could prove useful for rapid and efficient patient management.