Abstract C028: The differential burden of BRCA2 gene mutation in prevalent cancers in Nigeria: Any difference between Africa and the world?

Abstract

Abstract Introduction: The high mortality rate among cancer patients in Africa has been attributed to the high rate of late-stage presentation, aggressiveness, and metastatic nature of the tumors. The manifestation of cancer has also been linked with mutation of DNA repair genes including BRCA1, evidenced by the lack of expression of the tumor suppressors in the affected tissue. However, in Africa, there is a paucity of studies on the frequency of BRCA2 gene mutation in prevalent cancers. This study determined the prevalence of BRCA2 mutation in common cancers in Nigeria in a bid to compare the disparity of the mutation between Africa and elsewhere. Methods: This retrospective study included 51, 54, 58, 48, and 55 viable formalin-fixed Paraffin-embedded tissues of the breast, colorectal, endometrial, ovarian, and prostate cancers, respectively diagnosed between 2017 and 2019 in two tertiary health care facilities in Southern Nigeria. Tissues were stained for BRCA2 protein using the immunohistochemical technique, scored based on staining intensity, and documented as 0, +1, +2, and +3. Tissues with scores of 0 and +1 were considered negative whereas those with scores of +2 and +3 were considered positive. Descriptive, Chi-square test and Pearson’s correlation were carried out and significance was set at ≤0.05. Results: The mean age of women diagnosed with endometrial cancer was lower (41.34 ± 9.16 years) compared with breast, colorectal, ovarian, and prostate cancers (51.00 ± 10.98 years, 47.34 ± 14.73 years, 50.15 ± 12.29 years, and 72.66 ± 8.67 years, respectively). The prevalence of BRCA2 mutation was higher in endometrial cancer (78.4%) than in breast, colorectal, ovarian, and prostate cancers (41.5%, 25%, 54.2%, and 65.1%, respectively) at p< 0.001. There was a direct relationship between age and BRCA2 mutation among women with endometrial cancer (p= 0.005). Conclusion: This study suggests that the prevalence of BRCA2 mutation is high in Southern Nigeria and could be linked with the poor survival rate observed among cancer patients in West Africa. Citation Format: Jude Ogechukwu Okoye, Chiemeka Michael Emeka, Okechi Obioma. The differential burden of BRCA2 gene mutation in prevalent cancers in Nigeria: Any difference between Africa and the world? [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C028.