de Kraker J et al. (2004) Reduction of postoperative chemotherapy in children with stage I intermediate-risk and anaplastic Wilms' tumour (SIOP 93-01 trial): a randomised controlled trial. Lancet 364: 1229–1235

High rates of recurrence-free and overall survival have been achieved for Wilms' tumor, so the emphasis of current research is on reducing treatment-related toxicity. Results from the SIOP 93-01 trial indicate that postoperative chemotherapy can be shortened—potentially reducing the risk of side-effects—without compromising effectiveness.

This international non-inferiority study compared 2-year event-free survival in 410 children with stage I intermediate-risk or anaplastic Wilms' tumor. After preoperative chemotherapy and surgery, the patients received four doses of vincristine plus one course of dactinomycin. They were then randomized to the standard treatment of two further courses of the same chemotherapy (n = 210) or no further chemotherapy (n = 200).

At 2 years' follow-up, there had been 18 recurrences in the standard treatment group, compared with 22 in the children receiving shorter duration of treatment. Event-free survival—91.4% and 88.8% for the two groups, respectively—was not significantly different between the two groups. Five-year overall survival was approximately 95% in both groups.

The authors conclude that a shortened postoperative chemotherapy regimen is feasible in children with stage I intermediate-risk or anaplastic Wilms' tumor. This approach could reduce the burden of treatment in terms of acute and late side-effects, inconvenience for patients and parents, and health costs.