Real-world implementation of North American and SIOP strategies for the treatment of Wilms tumor in Uruguay.

Wilms tumor has been selected as an index tumor by the WHO Global Initiative for Childhood Cancer with the aim to improve cure rates worldwide. Nevertheless, there is a scarcity of published data on outcomes beyond those of the major cooperative groups. Therefore, we conducted a retrospective analysis including all patients with Wilms tumor treated at our referral center in Uruguay between 1995 and 2020. Treatment consisted of North American (NA) strategies in 23 cases (1995-2004), followed by the SIOP strategy in 35 cases thereafter. Staging included: I-II = 28, III = 7, IV = 14, and V = 9. There were no major surgical or medical complications; however, a delay in the administration of local radiotherapy was observed (median of 21 days after surgery). There were no cases of toxicity- or surgery-related deaths or treatment abandonment. Five-year probability of overall survival was 0.72 and 0.92 for the NA and SIOP groups, respectively. We conclude that outcomes were better for the SIOP strategy with no unexpected toxicities and high treatment compliance in both strategies. Timely implementation of radiotherapy was challenging.