Molecular Pattern of Breast Cancer Among A Series of Egyptian Patients

Abstract

Breast cancer is the most common neoplasm in women, accounting for 26 % of all cancers diagnosed annually, it is overall the second leading cause of cancer death (following lung cancer). In Egypt breast cancer constitutes 33 % of all female cancer and the median age is 46 years old, one decade younger than corresponding western countries. The incidence of breast cancer is highest among women of higher socioeconomic background. Also the incidence is higher among whites less common in black women. Most cancer patients are diagnosed sporadic and not associated with any clear familial predisposition 1. Breast cancer is not a single entity but instead comprises several biologically distinct subtypes. Based on molecular profiles, breast cancers have been classified into four main subtypes: luminal subtype A, luminal subtype B, ERbB2 positive receptors (HER2 positive/ER negative) and TNBC 2,3,4. Triple-negative breast cancer (TNBC) is defined as a clinical entity referring to tumors that do not express estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor receptor 2 (HER2) accounting for approximately 15%-20% 5,6 of breast cancers. TNBC has important clinical implications, because it is typically high grade, and exhibits a high rate of proliferation 7,8. In general, compared with other subtypes of breast cancer, TNBC has a less favorable clinical outcome in terms of the nature and likelihood of