TRENDS IN PATTERNS OF TREATMENT OF CHILDHOOD-CANCER IN LOS-ANGELES COUNTY

To assess the proportion of children with cancer who have been managed by mainstream pediatric cancer programs, population-based cancer inci dence data for Los Angeles County (LAC) children (under 20 years of ag e) for the years 1972 through 1987 were linked with patient records of children registered with the two national cooperative pediatric oncol ogy groups, Children's Cancer Study Group and Pediatric Oncology Group . The proportion of children with cancer who were registered by cooper ative groups increased markedly over time: 9% of LAC children younger than 15 years of age who were diagnosed with cancer in 1972 were regis tered with cooperative groups, compared to 52% of those diagnosed in 1 980 and 62% of those diagnosed in 1987. Registration rates decreased w ith increasing age at cancer diagnosis. In the most recent time period , 1984-1987, 66% of LAC children diagnosed with cancer under age 5 yea rs were registered with cooperative groups compared to 62% of those wh o were 5 to 9 years old and 49% of those who were 10 to 14 years old; although they were frequently diagnosed with tumors considered to be c hildhood cancers, only 19% of LAC, there was no apparent bias in regis tration rates with regard to gender or racial-ethnic background. Among patients diagnosed in the period 1984-1987, children in the highest o f five socioeconomic status categories were underrepresented among reg istrants. Registration rates were highest (70% or greater) for patient s with acute lymphocytic and acute nonlymphocytic leukemia, medullobla stoma, hepatoblastoma, Wilms tumor, and rhabdomyosarcoma. Fewer than 5 0% of patients with other brain and central nervous system tumors, ret inoblastoma, other soft tissue sarcomas, and bone tumors were register ed with the cooperative groups.