Introduction: Cancer survivors may experience loneliness, which can impair the capacity to self-regulate lifestyle behaviors, induce systemic inflammation, and deteriorate mental and physical health. Previous studies have found an association between loneliness and health outcomes in the general population, but few studies have examined health effects of loneliness among cancer survivors and its differential effects by sociodemographic characteristics.
Methods: In a cross-sectional analysis of All of Us Research program data, we examined the association between loneliness (defined using the UCLA-3 items loneliness scale) and overall quality of life and four other health outcomes among cancer survivors aged ≥ 18 years in the United States (N = 17,367).
Results: Lonely cancer survivors were more likely to have fair/poor overall quality of life, severe pain, severe fatigue, and fair/poor physical and mental health compared to non-lonely cancer survivors, controlling for multiple health behaviors and sociodemographic factors. Models stratified by sociodemographic characteristics generally showed similar results, but differences existed between some age, sex, and living arrangement subgroups. For example, the association between loneliness and fair/poor mental health was stronger among older survivors (≥ 65 years, AOR = 5.30; 95% CI = 4.30-6.54) than younger survivors (18-39 years, AOR = 3.07; 95% CI = 1.95-4.85); p for difference < 0.05. The association between loneliness and severe fatigue was stronger among survivors living alone (AOR = 3.15; 95% CI = 2.33-4.25) than survivors living with others (AOR = 2.16; 95% CI = 1.81-2.59); p < 0.05.
Conclusions: Loneliness generally showed adverse association with all evaluated health outcomes, but the magnitude of associations varied between certain subpopulations. Results of this study suggest the need for screening and monitoring of loneliness among cancer survivors.
Keywords: Loneliness; Mental health; Physical health; Quality of care; Severe fatigue; Severe pain.
© 2026. The Author(s), under exclusive licence to Springer Nature Switzerland AG.