PATTERNS OF ENROLLMENT ON COOPERATIVE GROUP STUDIES - AN ANALYSIS OF TRENDS FROM THE LOS-ANGELES-COUNTY CANCER SURVEILLANCE PROGRAM

To assess the proportion of children diagnosed with cancer who are enr olled on studies conducted by the two national pediatric cooperative g roups, population-based cancer incidence data for Los Angeles county c hildren younger than age 20 for the years 1980 through 1987 were linke d with patient records of children registered with the Childrens Cance r Group (CCG) or the Pediatric Oncology Group (POG). For patients not enrolled on a protocol, demographic and disease characteristics were c ompared with summary eligibility requirements for CCG protocols that w ere open for enrollment during 1980-1987. The proportion of patients e nrolled on studies conducted by the cooperative groups varied with tum or type and age at diagnosis. When patients younger than the age of 10 were diagnosed at an institution affiliated with one of the groups, t he majority of those evaluated by our review as eligible for a study w ere enrolled on a protocol. The proportion of young patients entered o n study among those whose diagnosis was not made at a cooperative; gro up institution was generally smaller. Seventy-three percent of all pot entially eligible patients with acute leukemia diagnosed between 1980- 1987 were entered on a pediatric group protocol. Approximately 50% of all potentially eligible patients with brain tumors were entered on pr otocol. In contrast to this, less than 50% of patients older than the age of 14 and likely to be eligible for a study were entered on a pedi atric group protocol, regardless of the tumor type. Indeed, bone tumor s constituted the category of patients most likely to be enrolled, wit h 39% of all potentially eligible patients entered on a study in the p eriod examined. If the patient's diagnosis was made at a cooperative g roup institution, the individual was more likely to be entered on a pr otocol than if the diagnosis was made at a center outside the cooperat ive group network. It was not possible to determine the precise reason for this trend from the data available. Some explanations include pol icies at cooperative group institutions regarding admission of patient s older than age 14 and the availability of protocols from cooperative groups primarily focused on the treatment of cancers of adults.