Microsatellite Instability of BAT-26 and NR-24among Breast Cancer Patients in Senegal

Microsatellite instability high (MSI-H) tumours are known to have better prognosis than microsatellite stable (MSS) tumours and diagnostic characterization of these tumours reveal differences in clinical, pathological and molecular characteristics.Differentpopulations have variable results for MSI tumours due to varied environmental factors that influencediverse outcomes. Therefore, with the successes in the exploration of immunotherapy in cancers and currently in breast cancer, this study aims to evaluate the microsatellite phenotypes of breast cancer patients in Senegal to better understand the pattern of tumour progression and design therapies for improved treatment outcome. Sixty-five breast tumours were genotyped for microsatellite instability of BAT-26 and NR-24 markers.The results showed MSI in more than 50% of the tumours with variant alleles of 92.5% and 81.4% in BAT-26 and NR-24 respectively. Statistical significance (pvalue = 0.041) was observed for SBR grade between MSS and MSI tumours.This study shows the MSI phenotype of BAT-26 and NR-24 markers among breast cancer patients in Senegal with a positive correlation between MSI and SBR grade in NR-24 marker. We propose thatNR-24 whichoften shows little or no variation among healthy individuals in different populations may be a marker of interest in the determination of MSI status as a prognostic factor among breast cancer patients in Senegal. --------------------------------------------------------------------------------------------------------------------------------------Date of Submission: 30-12-2018 Date of acceptance: 14-01-2019 --------------------------------------------------------------------------------------------------------------------------------------