A clinicopathologic study of triple negative breast cancer.

Background: Triple negative breast cancers (TNBC) are defined by absence of estrogen and progesterone receptors (ER and PR) and absence of overexpression of human epidermal growth factor receptor 2 (Her2). They are associated with poor prognosis. The purpose of this study is to study the clinicopathologic parameters of TNBC such as age, tumor size, stage, grade, and lymph node involvement and compare them with nonTNBC tumors. There are many studies which have shown that TNBC are similar to basal-like breast cancers (BBC). We have found the proportion of BBC in the TNBC group using surrogate immunohistochemical (IHC) markers cytokeratin5 (CK5) and epidermal growth factor receptor (EGFR). Materials and Methods: This is a retrospective study of 102 cases of carcinoma breast. Clinical records of the cases were retrieved. Histopathology slides and the IHC slides (ER, PR, Her2) were reviewed. Thus, two groups of patients were made TNBC and nonTNBC. Using the software SPSS version 16 statistical significance of the difference between clinicopathologic variables of the two groups was calculated. TNBC group was later studied for the presence of basal markers CK5 and EGFR using tissue microarray. Results: Statistically significant difference was found between the two groups in the variables such as mean age at diagnosis, mean tumor size, tumor grade, and the presence of lymphovascular invasion. Conclusions: TNBC formed 23.5% of total cases. Overall, TNBC were high grade tumors with larger size at diagnosis, presenting in younger women and showing lymphovascular invasion in a higher number of cases. 87.5% of TNBC were BBC. [ABSTRACT FROM AUTHOR]