Scholarly Journals--Published

  • Collins CL, Peng J, Singh S, Hamilton AS, Freyer DR. Patterns of Cancer Care and Association with Survival among Younger Adolescents and Young Adults: A Population-based Retrospective Cohort Study. Cancer Epidemiol Biomarkers Prev. 2021 Sep 3:cebp.0530.2021. doi: 10.1158/1055-9965.EPI-21-0530. Epub ahead of print. PMID: 34479948. (09/2021) (link)
  • Collins CL, Malvar J, Hamilton AS, Deapen DM, Freyer DR. Case-Linked Analysis of Clinical Trial Enrollment Among Adolescents and Young Adults at a National Cancer Institute-Designated Comprehensive Cancer Center. Cancer 2015 Dec; 121(24):4398-406. doi: 10.1002/cncr.29669. Abstract BACKGROUND: Poor accrual to cancer clinical trials may contribute to the lower improvement in survival observed for adolescents and young adults (AYAs) (those aged 15-39 years) with cancer. This has been difficult to quantify without reliable mechanisms to link incident cases with study enrollments. Using unique resources available at their National Cancer Institute-designated comprehensive cancer center, the authors compared the percentage of AYAs, children, and older adults enrolled onto cancer clinical trials and determined predictors of enrollment. METHODS: Patients diagnosed with cancer from January 2008 through December 2012 at 1 pediatric and 2 adult University of Southern California hospitals were identified through the California Cancer Registry and individually linked to institutional trial enrollment databases. The availability of clinical trials was assessed. RESULTS: Across the center, the enrollment percentage for AYAs (6%) was equal to that of older adults (6%), but was less than that for children (22%) (P < .01). Within the children's hospital, the AYA enrollment percentage was also less than that for children (15% vs 23%, respectively; P<.01). On multivariate analysis, diagnosis and site of care were found to be predictive of AYA enrollment onto therapeutic and nontherapeutic studies. Hispanic and Asian/Pacific Islander individuals were more likely to enroll onto nontherapeutic studies compared with non-Hispanic whites, but no racial/ethnic difference was observed for therapeutic studies. CONCLUSIONS: In the current study, the percentages of AYAs and older adults enrolled onto therapeutic trials were low but similar. Diagnosis, site of care, and race/ethnicity appear to be predictive of enrollment. Prospective mechanisms must be instituted to capture reasons for nonenrollment of AYAs and develop corrective interventions. (12/2015) (link)

Books and Chapters

  • Collins CL and Freyer DR. Adolescent and Young Adult Cancer in Los Angeles County: 1988-2011. Leukemia. Los Angeles Cancer Surveillance Program Monograph. 2014. (02/2016)


  • Deficits in clinical trial enrollment among adolescents and young adults with cancer treated at an academic medical center.  Purpose/Objectives: Improvement in survival for adolescents and young adults (AYAs, age 15-39) with cancer is worse compared to children and older adults.  This trend may be partly due to poor accrual to clinical trials.  We determined clinical trial enrollment at an academic medical center and compared the proportion of AYAs enrolled with children (age≤14) and older adults (age≥40) and between institutions within the center. Materials/Methods: The California Cancer Registry provided data on patients diagnosed with cancer 1/2008-12/2012 and treated at a University of Southern California (USC) Cancer Center institution.  At USC, oncology care is delivered in 3 settings: a children’s hospital, an adult cancer hospital and a county-run facility, which provides care to children and adults.  Patients identified by the registry were matched to institutional databases that track trial enrollments.  Differences in enrollment were determined by the chi-square test.  Results: Overall, 174 of 793 children (22%) were enrolled on therapeutic clinical trials compared to 104 of 1699 AYAs (6%) and 518 of 9311 of adults (6%) (p<0.01).  Enrollments among AYAs were higher at the children’s hospital (29/191, 15%) compared to either the adult cancer hospital (10/320, 3%, p<0.01) or county facility (65/1188, 5%, p<0.01).  However, within the children’s hospital, the proportion of AYAs enrolled on therapeutic trials (29/191, 15%) was significantly lower compared to children (174/761, 23%, p<0.01).  Of the 10 most frequent AYA diagnoses, 7 had clinical trials available, compared to 10 of 10 in children and 9 of 10 in adults. Conclusions:  The proportion of AYAs and adults enrolled on therapeutic trials is low, suggesting administrative barriers to enrollment.  Within a children’s hospital, lower enrollment among AYAs suggests other age-related barriers.  Trial availability may also contribute.  However, reasons for non-enrollment are not routinely captured, which prevents further analysis of the causes of low enrollment, and should be documented prospectively across treatment settings.  (12/2014) (link)