Abstract 6256: Prevalence of BRCA1 and BRCA2 proteins in breast cancer in a nigerian population and their relationship with different breast cancer morphological variants

Abstract Background: Breast cancer is the commonest site specific cancer in women and a leading cause of cancer death among women in Nigeria and globally. The trend in Nigeria and Africa is that breast cancers are seen in younger age groups, are of higher grades and follow an aggressive course. It has been suggested that this may largely be due to mutation in BRCA genes with the attendant alteration in function of its proteins. This study aimed at determining the prevalence of BRCA1 and BRCA2 proteins in breast cancers seen in our environment as well as to see any association between these proteins and different morphological variants. Materials and Methods: A descriptive study using tissue blocks of all histologically diagnosed breast cancer in our department between 2013 and 2017. Fresh sections were recut for histological grading and immunohistochemistry. Proteintech BRCA1 and BRCA2 polyclonal antibodies and detection kit were used. Results: One hundred and thirty (130) cases met the inclusion criteria for this study. The mean (SD) age of the patients was 44. 8 (10. 3) years with ages ranging from 26 to 79 years. There were more cases of breast cancer (73. 1%) seen before 50 years. Two (2) Male Breast Cancer (MBC) cases were seen, giving the female to male ratio of 64: 1. The commonest morphological variant encountered was Invasive Carcinoma, No Special Type at 84. 6% of cases. This was followed by invasive medullary (7. 8%). The least common variant was papillary cancer at 0. 8%. The tumors seen were mostly grade 3 (71. 2%), followed by grade 2 at 22. 7% and the least was grade 1 at 6. 1%. Positivity for BRCA1 and BRCA2 proteins was seen in 27. 7% and 30. 0% of cases respectively. One of the MBC showed reactivity for BRCA1 protein. No significant relationship was seen between BRCA 1/2 proteins expression and age or breast cancer histotypes. Conclusion: BRCA 1 and 2 proteins are an important risk factor for breast cancers seen in this environment. However, there is no association with age distribution and morphological variants of the breast cancer in our population. Citation Format: Solomon Raphael, Abdul Oluwasesan. Prevalence of BRCA1 and BRCA2 proteins in breast cancer in a nigerian population and their relationship with different breast cancer morphological variants abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 6256.