Pharmacogenomics of Chemotherapies for Childhood Cancers in Africa: A Scoping Review.

Abstract

Background: Pharmacogenomics holds significant promise in improving the efficacy and safety of chemotherapy for childhood cancers. However, the field remains underexplored in Africa, where high genetic diversity and substantial disease burdens, including cancers, create unique challenges. This review investigates the current state of pharmacogenomics research in childhood cancer chemotherapies across Africa, focusing on genetic variations influencing chemotherapy efficacy and adverse drug reactions. It also highlights critical gaps, such as limited infrastructure and insufficient healthcare worker knowledge, and emphasizes the importance of capacity-building initiatives in the region.

Methods: A scoping review was conducted encompassing studies published up to September 2024 that examined pharmacogenomic variations associated with chemotherapies in childhood cancer patients across Africa. The review included laboratory genetic analyses and surveys assessing healthcare workers' knowledge, attitudes, and perceptions regarding pharmacogenomics, particularly in the context of pediatric oncology.

Results: A total of 12 genes were identified across eight studies, including TPMT, CYP3A5, MDR1, MAPT, NUDT15, ITPA, IMPDH1, SLC29A1, SLC28A2, SLC28A3, ABCC4, and MTHFR. The most studied genes were TPMT and CYP3A5, which are involved in the metabolism of 6-mercaptopurine (6-MP) and vincristine, respectively. These studies spanned five African countries, including Kenya, Egypt, Zimbabwe, Nigeria, Tunisia, and Libya, and focused primarily on childhood cancers, particularly acute lymphoblastic leukemia. Chemotherapies frequently studied were 6-MP (reported in five studies), vincristine, cyclophosphamide, and methotrexate. Knowledge of pharmacogenomics among healthcare workers in Africa remains low, though a positive attitude towards its clinical applications was observed.

Conclusion: Pharmacogenomic variants, such as TPMT*3A, 3C, and CYP3A53, *6, significantly impact drug metabolism in African children with cancer. However, research remains regionally limited, and gaps in infrastructure and healthcare worker training persist. Expanding research efforts and improving pharmacogenomics capacity through pharmacist training and capacity-building initiatives are essential to advancing personalized medicine in Africa, ultimately improving treatment outcomes for pediatric cancer patients.