219 Background: Breast cancer is the commonest malignancy and major health issue globally. There is initial evidence and high possibility of molecular differences across the ethnic and geographic groups; responsible for variation in presentation, responses to treatment, and outcome. Methods: Breast cancer data from 2006 to 2010 at National Cancer Center, The Royal Hospital Oman was retrospectively retrieved from electronic record system, and analyzed with respect to ER, PR, and HER2 status. The molecular subtypes were correlated with age, histology, and treatment out come. The results were compared with published international/regional data. Results: Total 542 cases were available for evaluation (535 male and 7 male: 459 Omani and 83 Non-Omani). Right, left, and bilateral tumors were 42.6%, 51.4%, and 6%. IDC were 79.6%. G1 were 7.7%, while other grades were equally distributed. Luminal A, B, basal-like (TNBC), and HER2 positive were 35.9%, 15.8%, 25.5%, and 22.8% respectively. Their age (cut off 50 years) was a significant factor in basal-like (63.8% vs. 36.2%) and HER2 tumors (61% vs. 39%). High-grade tumors were highest (41%) in basal tumors and lowest in Luminal A (19%). Higher stage at presentation (stage 3 and 4) was highest in HER2 tumors (59%). Mortality was recorded higher 22.4% in basal-like/TN tumors. Table shows comparison with selected published data. Conclusions: The molecular classification and subtyping have shown ethnic and geographic variation in taxonomy. These differences may have diagnostic, therapeutic, and prognostic implications. Large scale and multicenter studies may confirm these findings. They can be translated and incorporated to management strategies wherever applicable. [Table: see text]
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.