Clinical Trial Enrolment In the Adolescent and Young Adult (AYA) Population with Hematologic Malignancies: A South Carolina (SC) Community Practice Perspective

Leukemias and lymphomas comprise 25% of all cancers in AYA patients age 15–39 years. Survival benefit from treatment advances has been less for AYA patients compared to the pediatric patients (<15 years of age). One reason for this disparity in survival is the relative lack of clinical trial accrual in AYA population. Previous population-based analysis of cooperative group participation between 1992 and 1997 found 71% of children under age 15 participated in clinical trials versus 24% of 15–19 year olds and less than 2% of 20–29 year olds (Liu et al., 2003). The majority of reports on this “AYA Gap” have been from large academic institutions or pooled national databases. We report our 5 year experience of clinical trial enrolment of AYA leukemias and lymphomas (L&L) from a SC community-based practice.

We retrospectively analyzed the data on all patients, age 0–39 years, with newly diagnosed acute leukemias(ALL, AML) and lymphomas (Hodgkin {HL} and non-hodgkin lymphoma{NHL}) between 2005 and 2009 through the Greenville Memorial Hospital (GMH) and BI-LO Charities Children's Cancer Center (BCCCC) registries in Greenville SC. AYA was defined ages 15–39, with the pediatric ages <15 as the control. Demographic comparisons were made with available state-wide and SEER registry data. Clinical trial availability was abstracted from practice clinical research offices and NCI database using www.clinicaltrials.gov.

Among 684 total oncology patients 0–39 years of age, 528 were AYA. Median age was 33 for the total AYA population but 26 for the 76 patients with L&L (ALL = 14, AML = 7, HL = 27, NHL = 28); there was no difference between the pediatric and AYA populations in regards to other demographic characteristics (race, gender, insurance, or vital status). Leukemia and lymphoma patients age 15–39 represented a similar distribution (4.7% and 10.4% of total diagnosis, respectively) in comparison to statewide and SEER data. Leukemia accounted for 80% of pediatric diagnoses while lymphoma comprised the bulk (72%) of AYA diagnoses; this is similar to data observed nationally. Statewide clinical trials were available to 72% of pediatric patients and 60% of AYA patients; local clinical trial availability was higher in the pediatric population than the AYA population (94% versus 69%). Sixty-two percent of pediatric patients were actually enrolled on a clinical trial in comparison to only 17% of AYA patients. Only 21% of AYA were treated at a pediatric facility, as compared to 98% of pediatric patients. Clinical trial enrollment of AYA patients treated at a pediatric facility was 75% versus 3% of patients treated at an adult facility. For the 97% of AYA patients treated at an adult facility but not enrolled on a clinical trial, 55% of patients had a trial available to them locally (34%) or statewide (21%). When considering lymphoma alone, as the most prominent AYA diagnosis, the majority of HL (89%) and NHL (82%) patients were not enrolled on clinical trials; of those patients not enrolled on a clinical trial, only 30% and 22% of HL and NHL, respectively, had a clinical trial available to them locally.

In a community-based adult and pediatric oncology practice, there is a significant discrepancy in the number of L&L patients enrolled on a clinical trial when comparing pediatric and AYA cohorts. AYA L&L patients fail to be enrolled on clinical trials due to lack of clinical trial availability as compared to the pediatric L&L population.

No relevant conflicts of interest to declare.