Survival rates of childhood cancer patients in Osaka, Japan

Background: Survival of childhood cancer patients is often described in specialized hospitals and/or institutions, but not in the general population. Methods: The trends and patterns of childhood cancer survival during 20 years were investigated using the Osaka Cancer Registry's data. The study subjects were 3443 reported cases diagnosed as having the first primary cancer between 1975 and 1994 at the ages of 0-14 years and who lived in Osaka Prefecture, excluding Osaka City. All childhood cancers were classified into 12 diagnostic groups according to the International Classification of Childhood Cancer based on the histology of the cancer. The 5 year relative survival was calculated by the Ederer 11 method. Results: The 5-year relative survival was 58% for all cancers. The survivals of retinoblastoma and kidney tumor patients were as high as 89 and 72%, respectively, whereas those of leukemia and liver tumor patients were as low as 45 and 47%, respectively. When divided into the first and second half-periods, the survival for all cancers was markedly improved from 48 to 68%. The survivals, especially for patients with leukemia, lymphoma, neuroblastoma, hepatoma and gonadal or embryonal tumors, were enhanced by >20% between the first and second half-periods. When these results were compared with those reported in England and Wales and the USA, however, the survivals for many diagnostic groups in Osaka were lower, except that for neuroblastoma. Conclusions: The survivals of childhood cancer patients have been markedly improved in Japan, but this finding suggested that the introduction and practice of chemotherapy was insufficient.