MOLECULAR SUBTYPING IN CASES DIAGNOSED AS INVASIVE BREAST CARCINOMA BY IMMUNOHISTOCHEMICAL METHOD AND THE RELATIONSHIP BETWEEN SUBTYPES AND PROGNOSTIC FACTORS

In this study, we analyzed retrospectively by immunohistochemical staining profiles of molecular subtyping of 79 invasive breast carcinomas in our clinic. It is aimed to evaluate the relation between prognostic factors and these subtypes (luminal A, luminal B, human epidermal growth factor receptor 2 (HER2) overexpressing, basal-like and null type). Immunohistochemically, ER, PR, HER2 and CK5/6 expressions were evaluated in selected tumor blocks of all cases. The most common histological type was invasive ductal carcinoma. Luminal A was the most frequent subtype. While most luminal A tumors were grade II, most basal-like tumors were grade III. The majority of grade I tumors were luminal A. Nearly half of the patients had tumors between 2-5cm in diameter at diagnosis. Similar to the literature, tumors rate smaller than 2cm was higher in luminal A type. 2 medullary carcinoma cases were consistent with the literature found in the basal-like type. In basal-like group, the tumor grade was higher than in other groups. Significant relationship was not found statistically between molecular subtypes and prognostic factors