A study of histomorphological profile of triple-negative breast cancer

BACKGROUND: Triple-negative breast cancer (TNBC) is defined by the lack of expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor 2 (Her2) expression. It is characterized by distinct clinical, morphological and molecular features and associated with aggressive clinical course and poor prognosis. PURPOSE: This study is aimed at examining the clinicopathologic features of triple- negative breast cancer and at evaluating the expression of CK 5/6 and epidermal growth factor receptor (EGFR) among 50 cases of triple-negative breast cancers and to correlate the expression of basal markers with the clinicopathologic prognostic parameters. MATERIALS AND METHODS: Fifty female patients with triple-negative breast cancer were studied for clinical and pathological features and by immunohistochemistry for CK 5/6 and EGFR expression. Statistical analysis was done using descriptive analysis and correlation tests. RESULTS: The mean age of the patients was 50.4 years. Infiltrating ductal carcinoma IDC, NOS type was the predominant histological type (46/50 [92%]). The commonest histologic grade was grade II (27/50 [55%]). Tumour necrosis was seen in 70% of the cases (35/50). 72% of the cases were positive for at least one of the basal markers CK 5/6 and EGFR. We observed a statistically significant correlation between tumour size and lymph node metastasis. CONCLUSION: The triple-negativity of tumours should not be used as a marker for basal-like tumours. The use of CK 5/6 and EGFR can define basal phenotype. A majority of the cases show EGFR expression. Hence TNBCs could be treated with EGFR targeted therapies