Age is not a prognostic factor in children with Wilms tumor beyond stage I in Africa

BACKGROUND: Patients under age 4 with stage I favorable histology (FH) Wilms tumor have a reported survival advantage. Among children above 10 years, a poorer prognosis has been associated with a higher prevalence of diffuse anaplasia. PURPOSE: To determine if, in our practice, patients with Wilms tumors >8 years of age (stage II-V) have a poorer prognosis than those aged <8 years or <4 years. PROCEDURE: Case-control study of 19 patients >8 years with Wilms tumor stages II-V who were identified from a cohort of 192 new patients (2002-2012). For each patient two controls were chosen matched for stage and histology, one 0-3 years and one 4-7 years. Neo-adjuvant chemotherapy was offered to all, combined with intensive supportive care. Postoperative treatment was determined by local stage and histology. OS and EFS at 5 years for the different age groups were compared. RESULTS: Each age group contained 19 patients, of whom 6 had stage II tumors, 3 stage III, 8 stage IV, and 2 stage V. Histology was intermediate risk (IR) in 17 and high risk (HR) in 2. OS at 5 years was 80.8% and EFS was 79.2% for the whole group. No significant difference in outcome could be shown between age groups. Loss to follow up was 6/57 (11%). CONCLUSIONS: The survival advantage of young age (<4 years) associated with stage I FH could not be demonstrated in higher stages. Age had no significant impact on prognosis although a trend to better outcome was seen in children <4 years.