Evaluation of human epidermal growth factor receptor-2 and hormonal receptor expression patterns in breast cancer from fine needle aspiration cytology

Abstract

Introduction: Breast cancer is the most common cancer among women, accounting for 22% of all female cancers. In breast cancer, the overexpression of human epidermal growth factor receptor-2 (HER-2/neu) is a prognostic marker indicated for stratification of patients for HER-2/neu targeted therapies, while estrogen receptor (ER) and progesterone receptors (PR) are additional prognostic markers in patients with early stage breast cancer and predictive for response to hormonal therapies. Fine needle aspiration cytology (FNAC), can provide enough cellular sample and evaluation of ER, PR and HER2/neu expression patterns has relevant clinical application because the sample can be collected before surgery and help plan management of breast cancer patients. The aim of the study was to evaluate and classify breast cancer by examining HER-2/neu, ER and PR expression patterns using cellblocks. Methods: A prospective cross-sectional study was carried out using FNAC samples from 30 patients with breast cancer. The ER, PR and HER2/neu protein overexpression patterns were determined by immunocytochemistry. Breast cancer cases were considered positive for ER and PR when 10% or more tumor cells were stained. The HER-2/neu overexpression was assessed on a scale of 0 to 3+ and a score of 3+ was considered positive. Results: Estrogen receptor positivity was observed in 50% of breast cancer cases, while PR positivity in 47% of the cases and HER2/neu was overexpressed in 13% of breast cancer cases. Conclusion: Immunocytochemistry performed on cell block is a feasible method for evaluation of ER, PR and HER-2/neu status in breast cancer, especially when the cellblock has adequate tumor cells.