Abstract
Cancer survivors face elevated risks of age- and treatment-related health conditions, possibly due to accelerated biological aging from cancer therapy. The role of social determinants of health (SDOH) in these aging trajectories remains understudied. We conducted a retrospective cohort study of 109,224 curatively treated Danish cancer survivors (lung, breast, prostate, or colon cancer, diagnosed between 1997 and 2018) and 574,022 age- and sex-matched cancer-free individuals. SDOH was assessed using educational level and cohabitation status. Using national registries, we investigated associations between SDOH and 16 post-cancer new morbidities with Cox proportional hazard models and flexible parametric models. During a median 6.9-year follow-up, cancer survivors had significantly higher rates of new morbidities than cancer-free individuals. Lung cancer survivors had elevated hazard rates for 14 morbidities, breast cancer survivors had increased rates for 12 morbidities, prostate cancer survivors exhibited elevated rates for 8 morbidities, and colon cancer survivors had rates for 14 morbidities. Educational disparities were evident: survivors with short education had higher rates for chronic respiratory disease (HRs: 1.30-1.55 across cancer types), heart failure (HRs: 1.50-1.54 in breast and colon), diabetes (HRs: 1.67-1.95 in breast, prostate, and colon), and depression (HRs: 1.32-1.37 in breast and colon). Living alone was also associated with increased but less pronounced rates. Cancer survivors experience elevated rates for age- and treatment-related post-cancer new morbidities compared to cancer-free individuals. Sociodemographic disadvantages, particularly short education, further increase these rates. These findings suggest that SDOH play an important role in post-cancer aging, highlighting the need for targeted interventions addressing social determinants in survivorship care.