Incidence of childhood cancer in Osaka, Japan, 1971-1988: reclassification of registered cases by Birch's scheme using information on clinical diagnosis, histology and primary site.

In 1971-1988, 4,021 malignant tumors occurring among children under 15 years of age were registered in the Osaka Cancer Registry, a population-based registry which covers Osaka Prefecture, Japan. These patients were reclassified into 12 diagnostic groups by Birch's scheme using information on clinical diagnosis, histology and primary site. The annual age-standardized incidence rate for childhood cancer per million children was 130.3 for males and 104.9 for females in 1971-88. Comparing the incidence rates for both sexes in 1981-88 with those in 1971-80 in Osaka, we observed a significant decrease of acute non-lymphocytic leukemia (ANLL) and a significant increase of all cancers, acute lymphocytic leukemia, non-Hodgkin lymphoma, sympathetic nervous system tumors, soft-tissue sarcomas, and gonadal and germ-cell tumors. Age-standardized incidence rates in around 1971-80 of the above-mentioned diagnostic groups were compared among 4 population-based registries; Osaka, Miyagi (Japan), SEER (U.S.), and the National Registry of Childhood Tumors (England and Wales). Rates for ANLL and gonadal and germ-cell tumors were higher and those for other diagnostic groups were lower in Osaka, especially for Hodgkin's disease. Thus, in 1980-88 in Osaka, rates for Hodgkin's disease remained low and rates for gonadal and germ-cell tumors increased, though rates for other cancers appeared to resemble the levels in caucasian populations. The incidence of childhood cancer in Japan was estimated according to the diagnostic groups in Birch's scheme.