Survival rates of childhood cancer patients in Osaka, Japan, 1975-1984.

Survival rates for childhood cancers were analyzed with a total of 2,209 cases who were registered in a population-based cancer registry in Osaka, Japan in 1975-1984. These cases were reclassified according to Birch's classification and the survival rate of each diagnostic group was calculated by Kaplan-Meier methods. Death certificate-only cases, which amounted to 3.9% of all incidence, were excluded from the calculation. The five-year cumulative survival rate for both sexes was 46% for all cancer children. Among 12 major diagnostic groups, the most favorable survival was seen in retinoblastoma (87.5%), followed by renal tumors, epithelial neoplasms, and gonadal and germ-cell tumors. The outcome was unfavorable in leukemias, sympathetic nervous system tumors, hepatic tumors and malignant bone tumors. Comparing the survival in 1975-1979 with that in 1980-1984, the rate for all childhood cancer rose from 41% to 51%. Improvement in survival was also observed in 4 groups; acute lymphocytic leukemia, acute non-lymphocytic leukemia, non-Hodgkin's lymphoma and osteosarcoma. One attributable factor for the rise of survival was proved to be improvement of medical treatment by Cox's hazard model analysis. Comparison of survival rates in Osaka with those in England and the U.S. revealed that the prognosis for acute lymphocytic leukemia and acute non-lymphocytic leukemia was less favorable in Osaka than in England and the U.S.