Germline sequence variation in cancer genes in Rwandan breast and prostate cancer cases

Abstract

Cancer genetic data from Sub-Saharan African (SSA) are limited. Patients with female breast (fBC), male breast (mBC), and prostate cancer (PC) in Rwanda underwent germline genetic testing and counseling. Demographic and disease-specific information was collected. A multi-cancer gene panel was used to identify germline Pathogenic Variants (PV) and Variants of Uncertain Significance (VUS). 400 patients (201 with BC and 199 with PC) were consented and recruited to the study. Data was available for 342 patients: 180 with BC (175 women and 5 men) and 162 men with PC. PV were observed in 18.3% fBC, 4.3% PC, and 20% mBC. BRCA2 was the most common PV. Among non-PV carriers, 65% had ≥1 VUS: 31.8% in PC and 33.6% in BC (female and male). Our findings highlight the need for germline genetic testing and counseling in cancer management in SSA.

Fig. 1. Inclusion and exclusion of breast and PC cases.

Detailed diagram of the processes of recruitment, testing and outcomes for breast and prostate cancer patients in Rwanda.

Fig. 2. Detected variants.

a Pathogenic variants in breast cancer cases. The figure provides details about the pathogenic variants found among breast cancer cases. The majority of the pathogenic variants were frameshift deletion, followed by nonsense mutations. b Pathogenic variants in PC cases. The figure provides details about the pathogenic variants found among prostate cancer cases. The majority of the pathogenic variants were frameshift deletion, followed by nonsense mutations and intronic mutations in equal distribution. c Variants of uncertain significance in fBC cases. The figure provides details about the variants of uncertain significance found among female breast cancer cases. The majority of the pathogenic variants were missense mutations, followed by intronic mutations. d Variants of uncertain significance in mBC. The figure provides details about the variants of uncertain significance among male breast cancer cases. All variants were missense mutations. e Variants of uncertain significance in PC. The figure provides details about the variants of uncertain significance found among prostate cancer patients. The majority of the variants of uncertain significance were missense mutations.