Immunohistochemical Expression of B-Cell Lymphoma-۲ Gene with Clinicopathological Correlation: A Comparative Analysis of Triple Negative and Non-Triple Negative Breast Cancers

Background: B-Cell Lymphoma-۲ gene is an anti-apoptotic protein associatedwith favorable prognosis in patients with breast cancer. The present study focusedon immunohistochemical expression of the aforementioned gene withclinicopathological correlation in non-triple negative breast cancers (NTNBCs)and triple negative breast cancers (TNBCs).Methods: We investigated ۲۵۸ cases of primary breast cancers; they weredivided into ۲ groups (NTNBCs and TNBCs) based on their expression of estrogenreceptor (ER), progesterone receptors (PR), and Her-۲/neu receptors. BCL-۲expression was correlated with age, tumor size, tumor grade, histological subtype,lymph node status, and lymphovascular invasion (LVI).Results: Among NTNBCs, ۶۸.۲% of cases expressed BCL-۲ as compared to۵۳.۳% in TNBCs (P-value = ۰.۰۳۵). In both groups, BCL-۲ expression wassignificantly higher in younger patients, without lymphovascular invasion andlower grade (borderline significant in TNBCs). The variable which was associatedwith higher BCL-۲ expression only in NTNBCs was smaller tumor size. Incontrast, in TNBCs invasive ductal carcinoma was significantly associated withBCL-۲ expression.Conclusions: BCL-۲ showed association with various clinicohistopathologicalcharacteristics in TNBC and NTNBC breast cancer patients. Yet, some of thesevariables were potentially related to better prognosis (the lack of LVI, smallertumor size, and lower grade). On the other hand, younger age, which is a featuregenerally associated with poorer prognosis, was significantly related to BCL-۲expression.

Keywords:

B-Cell Lymphoma-۲ (BCL-۲) , Non-Triple Negative Breast Cancers (NTNBcs) , Triple Negative BreastCancers (TNBCs) , Immunohistochemistry (IHC)