Abstract
BACKGROUND: Sedentary behavior and depressive symptoms are commonly observed in cancer survivors. However, the combined impact of these factors on the mortality outcomes of cancer survivors remains unknown. METHODS: Cancer survivors from the National Health and Nutrition Examination Survey (NHANES) (2007-2018) were selected. Multivariate-adjusted Cox regression analyses were employed to examine the intendent and joint prognostic effects of sedentary behavior and depressive symptoms on the mortality outcomes of cancer survivors. RESULTS: A total of 2,460 US adult cancer survivors (men = 1,143 and women = 1,317) were included. Severe sedentary behavior (≥ 8 h/day) was linked to higher all-cause [hazard ratio (HR) = 1.68, 95% confidence interval (CI): 1.36-2.09, p < 0.001] and noncancer mortality (HR = 1.80, 95% CI: 1.35-2.40, p < 0.001) in cancer survivors. Each additional hour of sedentary time increased the risk of all-cause (HR = 1.05, 95% CI: 1.02-1.08, p < 0.001) and noncancer mortality (HR = 1.07, 95% CI: 1.04-1.11, p < 0.001). Depressive symptoms (PHQ-9 ≥ 5) were also associated with higher all-cause (HR = 1.22, 95% CI: 1.01-1.48, p = 0.040) and noncancer mortality (HR = 1.27, 95% CI: 1.01-1.61, p = 0.045). In the joint analysis, cancer survivors with both depressive symptoms and severe sedentary behavior had the highest risk of all-cause mortality (HR = 2.06, 95% CI: 1.47-2.88, p < 0.001). Survivors with no depressive symptoms but severe sedentary behavior also had a higher risk (HR = 1.44, 95% CI: 1.10-1.88, p = 0.008). Additionally, the combination of depressive symptoms and severe sedentary behavior increased risks of cancer-specific (HR = 1.56, 95% CI: 1.04-2.34, p = 0.001), noncancer (HR = 1.86, 95% CI: 1.34-2.57, p < 0.001), and CMD-related mortality (HR = 1.74, 95% CI: 1.04-2.93, p = 0.037). In subgroup analysis, cancer survivors with endocrine-related and gastrointestinal cancers were more sensitive to these effects. CONCLUSION: Our study highlighted the importance of considering both sedentary behavior and mental health in making effective long-term follow-up recommendations for cancer survivors.