Loneliness trajectories and psychosocial, behavioral, and functional vulnerability among cancer survivors: A comparison of patients aged 50-64, 65-74, and ≥75 years

INTRODUCTION: Loneliness is common among older cancer survivors and may contribute to depressive symptoms, adverse health behaviors, functional decline, and loss of independence. National data on loneliness trajectories and survivorship-related vulnerability remain limited. MATERIALS AND METHODS: The study cohort included cancer survivors aged ≥50 years from the 2022 Health and Retirement Study, with age categorized as 50-64, 65-74, and 75 years or older. Loneliness was the primary exposure; 2020-2022 data were used to classify survivors as never lonely, or as having incident, resolved, or persistent loneliness. Survey-weighted logistic and linear regression models were used to evaluate associations between loneliness and psychosocial, behavioral, and functional measures after adjustment for sociodemographic characteristics, comorbidity burden, and self-rated health, as applicable. RESULTS: Among 2331 cancer survivors aged 50 years or older, mean age was 72.4 years, 59.5% (n = 1387) were female, and 18.6% (n = 433) reported loneliness. In cross-sectional multivariable analyses, loneliness was associated with higher odds of elevated depressive symptom burden (aOR, 11.21; 95% CI, 7.44-16.90), loss of independence (aOR, 1.53; 95% CI, 1.01-2.31), fair or poor self-rated health (aOR, 1.92; 95% CI, 1.35-2.72), and current smoking (aOR, 2.37; 95% CI, 1.06-5.29). In a separate adjusted linear regression model, loneliness was associated with a 3.10-point higher continuous Center for Epidemiologic Studies Depression score (β, 3.10; 95% CI, 2.82-3.39). In longitudinal trajectory analyses, persistent loneliness (aOR, 15.78) and incident loneliness (aOR, 8.32), but not resolved loneliness, were associated with elevated depressive symptom burden. DISCUSSION: Among cancer survivors aged 50 years or older in the United States, loneliness was associated with depressive symptom burden, worse self-rated health, current smoking, and loss of independence. Persistent and newly emergent loneliness identified survivors with the greatest depressive burden, supporting repeated loneliness assessment to guide targeted psychosocial, behavioral, and functional support.