Gregory C. Knapp, MD1; Olusegun I. Alatise, MD, MSc; Olalekan O. Olasehinde, MD, MSc; Ademola Adeyeye, MD3; Omobolaji O. Ayandipo, MD4; Martin R. Weiser, MD
The global burden of colorectal cancer (CRC) will continue to increase for the foreseeable future, largely driven by increasing incidence and mortality in low- and middle-income countries (LMICs) such as Nigeria.
We used the Wilson-Jungner framework (1968) to review the literature relevant to CRC screening in Nigeria and propose areas for future research and investment.
Screening is effective when the condition sought is both important and treatable within the system under evaluation. The incidence of CRC is likely increasing, although the exact burden of disease in Nigeria remains poorly understood and access to definitive diagnosis and treatment has not been systematically quantified. In high-income countries (HICs), CRC screening builds on a well-known natural history. In Nigeria, a higher proportion of CRC seems to demonstrate microsatellite instability, which is dissimilar to the molecular profile in HICs. Prospective trials, tissue banking, and next-generation sequencing should be leveraged to better understand these potential differences and the implications for screening. Fecal immunochemical test for hemoglobin (FIT) is recommended for LMICs that are considering CRC screening. However, FIT has not been validated in Nigeria, and questions about the impact of high ambient temperature, endemic parasitic infection, and feasibility remain unanswered. Prospective trials are needed to validate the efficacy of stool-based screening, and these trials should consider concomitant ova and parasite testing.
Using the Wilson-Jungner framework, additional work is needed before organized CRC screening will be effective in Nigeria. These deficits can be addressed without missing the window to mitigate the increasing burden of CRC in the medium to long term.