Breast cancer is the most prevalent neoplasm and the second leading cause of
death among females in Kenya. Estrogen and its metabolites are known risk
factors for breast cancer. Polymorphisms in these genes and breast cancer
susceptibility are unique among different populations. This study aimed to
determine the probable associations between estrogen-metabolizing gene
variations and other risk factors for breast cancer risk in Kenyan women.
Buffy coat samples were obtained from patients diagnosed with estrogen
receptor-positive breast cancer, benign breast disease, and healthy
volunteers. Genotyping of target polymorphisms was conducted using
polymerase chain reaction (PCR)-restriction fragment length polymorphism
(RFLP) analysis. The rs4646903 variant genotype CC was associated with
breast cancer in the case-control model (P=0.001); the heterozygous genotype
TC (P=0.01) and the luminal B molecular subtype (P=0.02) showed increased
odds of late-stage breast cancer. The rs1048943 variant genotype GG was
associated with breast cancer in the case-benign model (P=0.04), whereas CG
was associated with breast cancer in the case-control model (P=0.02). These
findings imply that the rs4646903 and rs1048943 variant genotypes are
involved in breast cancer risk in Kenyan women. Hence, they may be explored
further as potential markers for the disease.