A Survey in the Basal Like Breast Carcinoma Phenotype in North East of Iran

Breast carcinoma is not a homogenous disease. It is divided into 5 pathological subtypes of luminal1, luminal2, strongly Her2 positive, basal like, and normal breast like. Basal like breast carcinoma that accounts for about 15% of all breast cancers has an aggressive clinical behavior with the features of high nuclear grade, negative estrogen receptor, progesterone receptor, and Her2 reactivity (triple negative).
We aimed at identifying the prevalence of basaloid phenotype among triple negative (TN) cases in our region via immunohistochemistry (IHC) staining using basaloid markers.
We reviewed breast cancer patients in Omid and Imam Reza hospitals, Mashhad, Iran, between 2003 and 2007. We obtained the paraffin blocks from TN cases for immune-staining using cytokeratin 5/6 (CK5/6), cytokeratin 14 (CK14) and epidermal growth factor receptor1 (EGFR1) markers.
The incidence of TN disease among breast cancers was 21% (156/747). Based on IHC reactivity with at least one of the basaloid markers, from 59 available samples, 44 (75.4%) were basaloid.
In our region, most triple negative tumors were basal like breast cancer (BLBC). Among these cases, most immune-reactivity was observed for EGFR1, followed by CK14 and CK5/6.