Exercise and Diet Trials for Cancer Remain Scarce Across Africa, Registry Review Finds

A sweeping search of international clinical trial registries has revealed just how thin the evidence base is for one of the most promising, low-cost tools in modern cancer care. In a review published in Frontiers in Cancer Control and Society, a team of researchers led by Monica Wangari of Research Skills Lab-Africa in Nairobi systematically combed three trial registries for lifestyle and non-pharmaceutical oncology trials conducted anywhere on the African continent. The verdict: over nearly two decades, only 53 registered trials met the criteria, a number so small that it amounts to a rounding error compared with the trial output of high-income countries.

The stakes could hardly be higher. Cancer is the second leading cause of morbidity and mortality in Africa, with cancers of the cervix, breast, liver, colorectum and prostate ranked as the most common in the region. By 2030, new cancer cases are projected to increase by roughly 70 percent, with approximately one million cancer-related deaths annually. That burden is being driven by aging populations and the adoption of unhealthy habits, including physical inactivity, poor diets, and harmful tobacco and alcohol consumption, all colliding with health systems that are weak, underfunded and often unable to deliver timely screening and treatment.

Against that backdrop, lifestyle interventions, defined as programs that include nutritional and physical activity components plus at least one additional element such as behavioral therapy, counseling or stress management, have demonstrated benefits in reducing adverse cancer-related outcomes and improving quality of life. According to the World Health Organization, nearly one-third of cancer-related mortality is preventable through lifestyle interventions and behavioral modifications. Yet the critical analysis shows that most of the supporting evidence has been generated in high-income settings, and the extent to which these low-cost but highly promising interventions are leveraged in Africa remains poorly understood.

To map the landscape, the researchers searched ClinicalTrials.gov, the World Health Organization’s International Clinical Trials Registry Platform and the Pan African Clinical Trials Registry from July 2005, the date mandatory clinical trial registration was introduced, to October 2024. The initial search identified 193,789 trial records. After removing duplicates and screening titles, abstracts and full-text reports, 53 trials across nine African countries ultimately met the inclusion criteria: cancer-specific, conducted in at least one African country, and interventional rather than observational, with a primary non-pharmacological intervention such as diet, physical activity or behavioral support.

The geographical skew is stark. Egypt hosted 38 of the 53 trials, or 71.7 percent, followed by Nigeria with five and Kenya with four. Additional trials were undertaken in Malawi, Ethiopia, Tunisia, Rwanda, Botswana and Uganda. More than half of all trials, 73.6 percent, were conducted in North Africa, while only 13 trials were conducted exclusively in sub-Saharan Africa, the region bearing the heaviest burden. There were no trials reported from Central Africa at all, and only two studies from Southern Africa, one initiated in 2016 and another in 2023. The uneven distribution, the authors note, reflects existing regional differences in research infrastructure, funding availability, accessibility to high-quality care and disease burden prioritization.

The technical profile of the trials tells its own story. Most were randomized, 92.5 percent, and blinded, 71.7 percent, but sample sizes varied enormously, from small pilots of 20 to 40 participants to large implementation studies of up to 6,600. Breast cancer dominated the research agenda, accounting for 24 trials, or 45.3 percent, followed by colorectal cancer with six and acute lymphoblastic leukemia with four. Physical activity interventions were the most prevalent modality, constituting 43.8 percent of the 64 interventions identified, followed by psychological interventions at 23.4 percent and dietary interventions at just 9.4 percent. Educational, financial and technological interventions were markedly underrepresented, accounting for 7.8, 6.3 and 9.4 percent respectively, presenting what the authors describe as a unique opportunity for future research.

Sponsorship patterns reveal a structural fragility. Academic institutions sponsored 84.9 percent of trials, and 69.8 percent were locally sponsored by institutions within the host country. But the contrast between regions is dramatic: 92.9 percent of studies from sub-Saharan Africa were funded by external sponsors, while 92.3 percent of studies outside the region were funded by local sponsors. Notably, no industry partners funded any study in the review, in sharp contrast to pharmaceutical trials, where Egypt and South Africa have historically attracted commercial support. The authors conclude that industry investment is exclusively focused on pharmacological interventions, leaving lifestyle research entirely dependent on overstretched public and academic funding streams.

The comparison with high-income regions is sobering. In North America and Europe, lifestyle oncology trials have grown substantially over the past two decades, typically larger, longer in duration, with well-defined endpoints and dedicated cooperative trial networks. A landmark example is the CHALLENGE trial, conducted across 55 centers in Canada, Australia and the United Kingdom, which enrolled 889 colon cancer patients between 2009 and 2024 and demonstrated that a structured three-year exercise program significantly improved disease-free survival, with a hazard ratio of 0.72. By contrast, the 53 African trials identified in the review were overwhelmingly single-country, smaller in sample size and shorter in duration, with no industry co-investment, limiting the generalizability of evidence and its translation into clinical practice and policy.

There are signs of momentum. The earliest trial in the dataset was initiated in 2009, and registrations averaged two to three per year until 2022, after which the pace accelerated to more than five per year, peaking in 2023 with 16 or more studies registered. The review also documents a discernible shift toward more diverse beneficiaries: nearly one-third of lifestyle oncology trials included pediatric populations, and a growing number recruited caregivers and cancer survivors. Female participants dominated most studies, largely determined by the prevalence of breast and gynecological cancers, though the authors emphasize the pressing need to expand male inclusivity, particularly given the high prevalence of prostate cancer across the continent.

The bottom line, the authors argue, is that non-pharmacological interventions for cancer management appear nascent in Africa, and the full spectrum of lifestyle intervention-induced health outcomes is yet to be carefully explored for most cancers on the continent. In the current era of precision medicine, interventions proven successful in high-income countries cannot be assumed to work equally well in low- and middle-income countries, given genetic, socioeconomic and environmental differences. Given the lag in precision medicine research in Africa and the high cost of promising targeted therapies, the authors conclude that affordable, scalable and accessible lifestyle interventions deserve far greater research prioritization, especially in sub-Saharan Africa, where the cancer burden is heaviest and the resources for managing it are most constrained.

Subject of Research: A registry-based systematic review of lifestyle and non-pharmaceutical oncology interventions in Africa

Article Title: A registry-based systematic review of lifestyle and non-pharmaceutical oncology interventions in Africa

Article References: Wangari, M., Njoroge, E., Mburu, G., Mogeni, B., & Ouma, L. (2026). A registry-based systematic review of lifestyle and non-pharmaceutical oncology interventions in Africa. Frontiers in Cancer Control and Society, 4, Article 1571038. https://doi.org/10.3389/fcacs.2026.1571038

Image Credits: AI Generated

DOI: 10.3389/fcacs.2026.1571038

Keywords: registry-based, systematic, review, lifestyle, non-pharmaceutical, oncology, interventions, Africa, scientific research