Secondary Primary Neoplasms in Survivors of Wilms Tumour - A Population-based Cohort Study from the British Childhood Cancer Survivor Study

A British population-based cohort study was carried out to determine the risk of second primary neoplasms in survivors of Wilms' tumour. The cohort was obtained from the British Childhood Cancer Survivor Study, a population-based cohort study of treatment toxicities in 18,044 individuals diagnosed with childhood cancer, at an age of less than 15 years, between 1940 and 1991 in Britain. There were 1,441 Wilms' tumour survivors in the cohort: 732 males (50.8%) and 709 females (49.2%). Total follow-up from 5-year survival was 27,841 person years, mean follow-up of 19.3 years per survivor. There were 81 second primary neoplasms, including 52 solid neoplasms, 3 acute myeloid leukaemias and 26 basal cell carcinomas. Thirty-five of the 39 solid neoplasms that developed in the thoracic, abdominal or pelvic region occurred within irradiated tissue. The standardised incidence ratio for all solid second primary neoplasms was 6.7 (95% CI: 5.0-8.8). Cumulative incidence for all solid second primary neoplasms by ages 30, 40 and 50 years was 2.3% (1.4-3.5%), 6.8% (4.6-9.5%) and 12.2% (7.3-18.4%). The overall risk of second primary neoplasms in survivors of Wilms' tumour treated between 1940 and 1991 was substantial, and solid second tumours tended to develop in the irradiated tissue. Continued follow-up of these survivors is important to monitor such late effects of treatment. It is also important to evaluate the risk of second primary neoplasms following more recent lower radiation dose treatment practices.