Neighborhood disadvantages and longitudinal progression of multimorbidity among adult survivors of childhood cancer: a single-center St. Jude Lifetime Cohort Study in the U.S.

Background The impact of cancer therapy on chronic health condition (CHC) burden in childhood cancer survivors is well-established; however, the role of neighborhood-level social determinants of health (SDOH) remains underexplored. Methods In this single-center cohort study in the U.S., we analyzed 2508 survivors enrolled in the St. Jude Lifetime Cohort Study between 9/13/2007 and 4/20/2020, who were ≥5 years from diagnosis, ≥18 years of age, and had ≥2 clinical assessments. SDOH encompassed social vulnerability (Social Vulnerability Index) and environmental/healthcare access vulnerabilities (e.g., primary care physician [PCP] availability, food inaccessibility), categorized into quartiles. A total of 177 clinically assessed CHCs were aggregated into 48 CHC groups and a global burden. Multivariable logistic regressions examined associations between baseline SDOH and CHC progression from baseline to follow-up, adjusting for clinical and sociodemographic factors. Global CHC burden progression was the prespecified primary outcome; analyses of specific CHC groups and effect modification by personal socioeconomic status were exploratory. Findings Survivors residing in the most vs. least vulnerable neighborhoods, characterized by low income (odds ratio [OR]: 1.83, 95% confidence interval [CI]: 1.36–2.46), limited PCP availability (OR: 1.30, 95% CI: 1.03–1.64), and food inaccessibility (OR: 1.49, 95% CI: 1.08–2.07), had higher risks of global CHC burden progression. Living in SDOH-vulnerable neighborhoods was associated with higher risks of new-onset/worsening of multiple CHC groups, including low education for peripheral nervous system disorders (OR: 2.69, 95% CI: 1.63–4.43), food inaccessibility for arrhythmias (OR: 4.36, 95% CI: 1.32–14.35), and poor walkability for abnormal glucose metabolism (OR: 4.60, 95% CI: 1.41–15.04). Among publicly insured survivors, limited PCP availability and poor walkability were associated with higher risk of peripheral musculoskeletal disorder (OR: 6.11, 95% CI: 2.33–16.04, OR: 7.37, 95% CI: 2.82–19.27). Interpretation SDOH are associated with CHC severity progression among childhood cancer survivors, supporting multilevel social risk assessment in survivorship care and further evaluation of neighborhood-informed risk stratification. Funding U.S. National Cancer Institute.