Expression of Basal-like Biomarkers in Triple Negative Invasive Breast Carcinoma in Puerto Rico

Routine Progesterone and Estrogen hormone receptor proteins and human epidermal growth factor receptor 2 (HER-2) analysis on invasive breast carcinomas provide therapeutic and prognostic values, revealing significant subgroups: luminal A, luminal B, HER-2 and the "triple negative" tumors. The aim of this study was to determine the expression of basal cytokeratins and Epidermal Growth Factor Receptor in "triple negative" invasive breast carcinomas in Puerto Rico women.

All invasive breast carcinoma cases received from 2008 to 2010 were included. Assessment of tumoral expression of Estrogen Receptor, Progesterone Receptor and HER-2 was performed. The cases were divided into groups based on their molecular categories and analyzed according to the age. "Triple negative" tumors were further analyzed according to their expression of Epidermal Growth Factor Receptor and cytokeratins 5/6 and 14.

From 717 cases reviewed, 487 cases of invasive breast carcinoma were included. The molecular categories were 66%, 10%, 9% and 15% for the luminal A, luminal B, Her-2 and "triple negative" groups, respectively. No significant difference (p= 0.64) was observed between the molecular categories and the age of the patients. Assessment of basal cytokeratins and Epidermal Growth Factor Receptor expression was performed on 41 "triple negative" tumors; 71% expressed at least one basal cytokeratin or Epidermal Growth Factor Receptor and 29% were negative to all markers.

Prevalence and relation between the molecular categories and the expression of basal cytokeratins in "triple negative" tumors in our population is comparable to other published data.