Genetic Determinants of Cancers in Sub-Saharan African-based Populations: A Systematic Review

Abstract

Cancer is the leading, singular cause of human deaths worldwide. It has both an inherited and a biological component and its
burden is rising in Africa. The African population is grouped into North Africa (NA) and Sub-Saharan Africa (SSA) and from a
genetic perspective, NA shares much of their ancestry with Eurasia. Therefore, both African population sub-types would possess
distinct cancer genetic make-up based on these ancestral origins. Thus, the aim of this study was to demonstrate any distinction
in the genetic variant of SSA cancer types, by reviewing all genetic studies that investigated the genetic variants of cancers in
this region. A review of all molecular genetic studies that interrogated the candidate genes and susceptible variants of cancers
in SSA-based populations were reviewed. Our search methodology was modelled after the Cochrane systematic review protocol,
which included MeSH terms and related keywords. Some 47 articles studying 7 cancer types in 12/48 SSA countries, met the
inclusion criteria. All studies screened for polymorphisms using PCR-based techniques. Despite five studies showing statistically
significant genetic association to their targets, their findings were rather suggestive than empirical, as no study replicated or
validated the detected variants. Accurate reporting in SSA-based population cancer study is predicated on large scale studies and
confirmation of actionable genetic markers for better understanding of the genetic risk. We recommend large scale genome
association studies using contemporary techniques, in a multi-country setting and Sub-Saharan Africa having less molecular
genetic research, than Northern Africa should be addressed..