Estimating cancer treatment intensity from SEER cancer registry data: methods and implications for population-based registry studies of pediatric cancers.

OBJECTIVE: The Intensity of Treatment Rating (ITR) Scale condenses treatment and clinical characteristics into a single measure to study treatment effects on downstream health outcomes across cancer types. This rating was originally developed for clinicians to determine from medical charts. However, large studies are often unable to access medical charts for all study participants. We developed and tested a method of estimating treatment intensity (TI) using cancer registry and patient self-reported data. METHODS: We estimated two versions of TI for a cohort of pediatric cancer survivors-one utilized information solely available from cancer registry variables (TIR) and the other included registry and self-reported information (TIS) from survey participants. In a subset of cases (n = 135) for whom the gold standard TI (TIC) was known, both TIR and TIS were compared to TIC by calculating percent agreement and weighted Cohen's kappa, overall and within cancer subtypes. RESULTS: In comparison to TIC, 71% of TI scores from both methods were in agreement (k = 0.61 TIR/0.54 TIS). Among subgroups, agreement ranged from lowest (46% TIR/39% TIS) for non-defined tumors (e.g., "Tumor-other"), to highest (94% TIR/94% TIS) for acute lymphoblastic leukemia (ALL). CONCLUSIONS: We developed a methodology to estimate TI for pediatric cancer research when medical chart review is not possible. High reliability was observed for ALL, the most common pediatric cancer. Additional validation is needed among a larger sample of other cancer subgroups. The ability to estimate TI from cancer registry data would assist with monitoring effects of treatment during survivorship in registry-based epidemiological studies.

Childhood Cancer Survivorship and Substance Use Behaviors: A Matched Case-Control Study Among Hispanic Adolescents and Young Adults.

PURPOSE: This case-control study compared substance use behaviors between Hispanic adolescent and young adult survivors of childhood cancers (cases) and a community sample of participants without cancer (controls). METHODS: A total of 100 cases were matched to controls (200 participants) one to one by ethnicity, age, and sex (mean age at survey 19.27, standard deviation = 1.92). Differences in self-reported previous 30-day use of tobacco, alcohol, binge drinking of alcohol, and marijuana were examined using conditional multivariable logistic regression. RESULTS: The odds of tobacco, alcohol, binge drinking, and marijuana use were significantly lower for cases than for controls (all p's <.05). When stratified by age, cases (vs. controls) under 21 years of age reported lower levels of substance use (all p's <.05), whereas differences over the age of 21 were nonsignificant. CONCLUSIONS: Lower levels of substance use among Hispanic adolescent and young adult survivors of childhood cancers (vs. controls) are most apparent at younger ages. Future work needs to examine a potential delay in initiation of use among survivors.