Until now, direct comparisons of cancer survival between high-income and low-income countries have not generally been available. The information provided here might therefore be a useful stimulus for change. The findings should eventually facilitate joint assessment of international trends in incidence, survival, and mortality as indicators of cancer control.

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Background. Cancers of individual organs generally are composed of various histologic types, each with its own frequency and demographic patterns. For childhood cancers in particular, a classification of cancers by histologic type is important for understanding the etiology and progression of the disease. Methods. Data from the Surveillance, Epidemiology, and End Results (SEER) Program on 9308 microscopically confirmed malignant neoplasms in children younger than age 15, newly diagnosed during 1973‐1987, were made available for analysis. Tumors were grouped histologically according to a classification previously utilized in an international volume of childhood cancer incidence. Results. The most frequent histologic types were acute lymphocytic leukemia (23.6%), astrocytoma (9.6%), neuroblastoma (6.6%), and Wilms' tumor (6.4%). Acute lymphocytic leukemia accounted for 75% of childhood leukemia. The most common form of Hodgkin's disease was the nodular sclerosing subtype, which was diagnosed in 56% of all cases. Burkitt's and Burkitt‐like disease accounted for approximately one third of non‐Hodgkin's lymphoma, the sex ratio (male to female) being unusually high (5.7). Among the brain tumors, glioma was of interest because 198 cases (excluded from this analysis) were diagnosed without histologic confirmation—due, no doubt, to their inaccessibility for biopsy because they were located in the brain stem. The most common histologic type of soft tissue sarcoma was rhabdomyosarcoma, which accounted for 51% of the total, more than half of which were of the embryonal type. To the authors' knowledge, this report offers for the first time the relative frequencies of rare types of leukemias, such as megakaryoblastic leukemia, in childhood. This report also includes the frequencies of 21 rarer forms of soft tissue sarcoma. Five forms of childhood cancer had a 5‐year relative survival rate of 85% or better. Of the cancers with the poorest outcome, three had relative survival rates of 46.5‐49%; the relative survival rate for acute myelogenous leukemia was only 26.4%. The trends in survival over time for 21 types of childhood cancer also are included in this report. Conclusions. Further refinements in classification now are available through laboratory techniques utilizing molecular biology, immunology, and cytogenetics, which are of importance in etiologic studies, diagnosis, treatment, and prognosis. It would be important in the future for cancer registries to record the results of relevant laboratory tests for further analysis by subtype.

Incidence and survival data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program for the 10-year period 1973-1982 are presented. Childhood cancer incidence rates have remained relatively stable over the last decade. The overall incidence rate increased slightly from 124 to 127 per million children from 1973-1977 to 1978-1982 while rates for leukemias remained unchanged over this same time period at 38 per million for all races combined. Leukemias and lymphomas accounted for 44% of all cancers among white children and 33% among blacks. For all forms of cancer combined, the 5-year relative survival rate was 57% for both whites and blacks. The 5-year relative survival rate exceeded 80% for fibrosarcomas, retinoblastomas, Hodgkin's disease, and gonadal and germ cell tumors. Survival rates for children have shown improvement during the last decade, the most dramatic improvements occurring among patients with leukemia (15% 5-year relative survival in 1967-1973 versus 51% in 1973-1981), non-Hodgkin's lymphoma (24% versus 51%), and bone tumors (28% versus 48%).