Presence and prevalence of single nucleotide sequence polymorphisms in TP53 and BRCA2 genes as of cervical and ovarian cancers in women using hormonal contraceptives in Abuja, Nigeria

Abstract

Background: Cancer remains a major health burden in sub-Saharan Africa, characterised by high incidence and mortality rates as a result of late diagnosis, limited access to treatment and poor outcomes. Among gynaecological malignancies, cervical and ovarian cancers are of particular concern. Emerging evidence suggests that hormonal contraceptives may influence genetic susceptibility through single nucleotide polymorphisms (SNPs) in cancer-related genes such as TP53 and BRCA2.
Aim: This study investigated the prevalence of SNPs in the TP53 and BRCA2 genes and their association with cervical and ovarian cancer risk in a selected population.
Setting: Civil Defence Medical Centre, Abuja, Nigeria.
Methods: A total of 108 samples were analysed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to detect gene polymorphisms. Single nucleotide polymorphisms were confirmed at the nucleotide level using purified PCR products, and deoxyribonucleic acid (DNA) fragments were sequenced with a Genetic Analyzer 3130xl (Applied Biosystems). BioEdit and MEGA 6 software were used for genetic analysis.
Results: Polymorphisms were detected in the TP53 gene, but not in BRCA2. The TP53 variants were predominantly missense mutations, including G > A (40%) and G > C (60%) substitutions. Among 98 hormonal contraceptive users, 5 (5.1%) had TP53 SNPs. No BRCA2 SNPs were identified. Fisher’s exact test showed marginal statistical significance (p = 0.059).
Conclusion: The findings underscore the relevance of TP53 screening in populations at risk of cervical cancer, while BRCA2 screening may be less applicable in this cohort. Larger studies across diverse populations are recommended.
Contribution: However, further research is needed with larger sample sizes in other geographical regions and additional genetic markers to fully understand the genetic risk landscape for both cancers in hormonal contraceptive users within the population.