An Exploratory Analysis of Fecal Immunochemical Test Performance for Colorectal Cancer Screening in Nigeria

Abstract

Introduction The fecal immunochemical test (FIT) for hemoglobin is recommended for colorectal cancer (CRC) screening in resource‐limited environments. However, there are several unique variables that may alter FIT performance in this setting, including endemic intestinal parasites and high ambient temperature. This prospective study evaluated the performance of FIT in asymptomatic, average‐risk individuals of screening age in rural Nigeria. Methods Three hundred and twenty‐four community volunteers completed a questionnaire and provided stool specimens for parasitology and microbiome analysis. Specimens were frozen and stored at −80 °C. Of 324 subjects, 139 met criteria for average‐risk CRC screening and had a stool sample for analysis. These were thawed and tested with a qualitative FIT. Specimens positive for occult blood were retested every two days to evaluate the impact of time and temperature on test performance. Results Of 139 individuals, 69 (49.6%) were positive for intestinal parasites and 10 (7.2%) were positive for occult blood. The most common pathogen was Cryptosporidium (40.6%). Among patients with intestinal parasites, 10.1% (7/69) had a positive FIT. Only 4.3% (3/70) of patients without parasites had a positive FIT (p = 0.208). On bivariate analysis, sociodemographic variables were not associated with a positive FIT result. Thirty percent (3/10) of the FIT‐positive specimens became FIT‐negative with routine storage. Conclusion Although a positive FIT result was more common in those with parasitic infection, the relationship was not significant in this small cohort. The impact of high ambient temperature on test positivity may necessitate shorter processing time guidelines for equatorial countries. Additional prospective studies are needed to validate FIT performance in Nigeria.

Artificial intelligence and machine learning for early detection and diagnosis of colorectal cancer in sub-Saharan Africa

“…Non-invasive screening tests include faecal occult blood testing, FIT and stool-based DNA tests17 24; however, widespread adoption of stool-based approaches remains suboptimal in both high-income countries as well as SSA 25–28. In addition, questions about the impact of high ambient temperature and endemic parasitic infection as well as the practicality and cost-effectiveness of these approaches in SSA remain 29–31. Regardless, endoscopy is still needed for diagnosis and prognosis.…”

“… 25–28 In addition, questions about the impact of high ambient temperature and endemic parasitic infection as well as the practicality and cost-effectiveness of these approaches in SSA remain. 29–31 Regardless, endoscopy is still needed for diagnosis and prognosis. Thus, early detection strategies that target those at the highest risk benefit from these limited services are paramount.…”