Risk factors, tumour biology and genetics of breast cancer in Cameroon: a pilot study

Breast cancer is the most common cancer among women in sub-Saharan Africa (SSA) and more than 40% of women with breast cancer are diagnosed before age 45 in these settings. However, despite the high burden of breast cancer among younger women, the drivers of breast cancer pathogenicity and the proportion of early breast cancers attributable to hereditary causes is unknown. Pathogenic variants (PV) in BRCA1/2 genes are associated with a 60-80% increased lifetime risk of breast cancer. Furthermore, there are few studies that have investigated the association between the tumour hormone receptor status, and the presence of a PV in breast cancer susceptibility genes in SSA, and no such studies have been done in Cameroon. So, I will do a pilot study recruiting 150 women with a breast cancer diagnosed at age 45 or below and 150 women diagnosed after age 45 in Cameroon. For all patients, I will study their tumour hormone receptor status; for patients diagnosed at ≤ 45 years, or with a triple-negative breast cancer irrespective of age, a saliva sample will be collected for DNA extraction, to determine what proportion of these patients carry a germline pathogenic variant using whole exome sequencing.