Prevention of treatment abandonment remains an important challenge to increase survival of Wilms tumor in sub‐Saharan Africa: A report from Wilms Africa—CANCaRe Africa

Abstract Background The Wilms Africa studies implemented an adapted Wilm's tumor (WT) treatment protocol in sub‐Saharan Africa in two phases. Phase I began with four sites and provided out‐of‐pocket costs. Phase II expanded the number of sites, but lost funding provision. Objective is to describe the outcomes of Phase II and compare with Phase I. Methods Wilms Africa Phase I ( n = 4 sites; 2014–2018) and Phase II ( n = 8 sites; 2021–2022) used adapted treatment protocols. Funding for families’ out‐of‐pocket costs was provided during Phase I but not Phase II. Eligibility criteria were age less than 16 years and newly diagnosed unilateral WT. We documented patients’ outcome at the end of planned first‐line treatment categorized as treatment abandonment, death during treatment, and disease‐related events (death before treatment, persistent disease, relapse, or progressive disease). Sensitivity analysis compared outcomes in the same four sites. Results We included 431 patients in Phase I ( n = 201) and Phase II ( n = 230). The proportion alive without evidence of disease decreased from 69% in Phase I to 54% in Phase II at all sites ( p = .002) and 58% at the original four sites ( p = .04). Treatment abandonment increased overall from 12% to 26% ( p < .001), and was 20% ( p = .04) at the original four sites. Disease‐related events (5% vs. 6% vs. 6%) and deaths during treatment (14% vs. 14% vs. 17%) were similar. Conclusion Provision of out‐of‐pocket costs was important to improve patient outcomes at the end of planned first‐line treatment in WT. Prevention of treatment abandonment remains an important challenge.