Human epidermal growth factor receptor 2 oncoprotein expression in breast cancer patients from central Anatolia, Turkey

Abstract

AbstractAim: Human epidermal growth factor receptor 2 (HER2) overexpression is associated with poor prognosis and the frequency of HER2 positivity in breast cancer patients varies among different regions of the world. We studied HER2 expression in Turkish breast cancer patients.Methods: HER 2 expression was evaluated immunohistochemically in 107 breast cancer patients. HER2 expression was reported as negative or positive (3+) according to cellular membrane staining characteristics. The frequency of HER2 overexpression, distribution according to clinical characteristics, effect on survival and effect of chemotherapy on survival in relation to HER2 overexpression was evaluated.Results: The median age of patients was 49 years (range 27–76). HER2 was 3+ in 34 patients (31.8%). There was no significant difference in age, menopausal status, histopathology, lymph node involvement, stage and estrogen and/or progesterone receptor positivity in relation to HER2 expression. Forty‐three patients (40.2%) relapsed and 21 patients (19.6%) died during the follow‐up period. There was no significant difference in the relapse rate, distribution of relapse sites and death rate in relation to HER2 expression. The 3‐ and 5‐year disease free survival rates were 67.1 and 40.5%, and the overall survival rates were 87.5 and 66.1%, respectively. Survival rate and calculated survival time were relatively shorter in HER2 3+ patients than in non‐HER2 3+ patients, but these differences were not statistically significant. HER2 status did not affect survival period according to chemotherapy group.Conclusion: Immunohistochemistry findings of HER2 expression in Turkish breast cancer patients were similar to those found in the published reports. A shorter survival period was observed in HER2 3+ patients, but the difference was not statistically significant.