Abstract A103: Breast cancer molecular subtype analysis in Egypt reveals high prevalence of Luminal A: Implications for improving prognosis

Abstract

Abstract The World Health Organization has ranked breast cancer as the most common type of cancer among women world-wide. Breast cancer represents 37% of cancer cases in Egypt, and although incidence in Egypt remains lower than in highly developed countries, incidence rates are steadily increasing. Breast cancer is a heterogeneous disease composed of a number of recognizable subtypes. These intrinsic tumor subtypes, based on molecular gene expression profiles, reflect underlying biological behavior of tumors. The distribution of molecular subtypes in women of North African descent is currently unknown. Although parity is a contributing factor to the breast cancer dilemma in Egypt, understanding the underlying and unique molecular genetic factors is critical for tackling this disease in Egypt. Accordingly, our study examined the prevalence of breast cancer subtypes in Egypt in specimens obtained from medical centers in Cairo and Minya. We classified tumors according to an accepted IHC panel of surrogate markers for intrinsic subtype. Our study results demonstrated that in spite of younger age, larger tumor size, high tumor grade and high percentage of node positive cases, the Luminal A subtype was found in over 55% of cases examined. There was a surprisingly low prevalence of the basal-like subtype which was found in less than 10% of cases. Luminal B, HER2+/ER-and non-basal triple negative tumors also each constituted less than 15% of cases examined. Thus, although Egyptians with breast cancer have more aggressive disease at diagnosis and dismal survival rates, they appear to have favorable underlying biology. We feel this study will help raise awareness of the breast cancer problem in Egypt and aid the clinician in making better treatment and prognostic decisions based on a set of already known prognostic and therapeutic markers. Citation Information: Cancer Epidemiol Biomarkers Prev 2010;19(10 Suppl):A103.