SIOP treatment guidelines for renal tumours in small infants: fact or fantasy?

Aims: Since as far back as 1980, SIOP (Societe Internationale d'Oncologie P ediatrique) have advocated primary nephrectomy (PN) only for unilateral ren al tumours in patients less than or equal to6 months of age. Patients aged 7-12 months have been pre-treated with chemotherapy before nephrectomy is p erformed. The aims of this study were: (1) to evaluate how the SIOP guideli nes for infants 0-6 months and 7-12 months of age were followed in three Du tch centres for Paediatric Oncology before and after 1980, and (2) to carry out an inventory of the incidence of benign tumours in this patient popula tion below 12 months of age. Methods: Retrospective analysis of 67 patients under 12 months of age (1969 -1995) with a unilateral renal tumour at diagnosis was carried out. Demogra phics, pathology, staging and treatment variables were analysed. Results: Of 67 patients, 39 were male and 28 female. Twenty-six (39%) infan ts were 0-6 months of age (group A) and 41 (61%) were 7-12 months old (grou p B). In group A there were five patients (19%) with congenital mesoblastic nephr oma (CMN), out of which one was still-born and therefore received no treatm ent, and 21 patients with a unilateral Wilms' tumour (WT). Fourteen of the 25 patients (56%) were treated with PN, including four patients with CMN. In group B there was one patient (2%) with CMN and 40 patients with WT. Thi rteen of the patients (31%) were treated with PN. A total of 15 patients were treated before 1980 and 26 after 1980. Eight of 15 (53%) patients were treated with PN before 1980 and 21/26 (81%) were pr e-treated after 1980. according to the protocol. Conclusion: Despite the SIOP recommendations, only 56% of patients less tha n or equal to6 months were treated with PN. The percentage of pre-treated p atients in group B increased after changing the protocol in 1980 to 81%. In the age group included in the SIOP studies the protocol had been used sign ificantly more often compared to the group included in the guidelines only. The known excellent survival rate justifies a primary nephrectomy approach in the youngest age group, however, in cases of a large tumour, pre-operat ive chemotherapy in reduced doses may still be considered. In our study few er CMN were found (19%) than reported in the SIOP studies (20-70%), most li kely due to a low registration rate, as a consequence of excluding this ver y young age group (0-6 months) from the SIOP protocol. (C) 2000 Harcourt Pu blishers Ltd.