Leisure-time physical activity, daily sitting time, and mortality among US skin cancer survivors.

PURPOSE: To investigate the long-term effect of sitting time and physical activity after a skin cancer diagnosis. METHODS: A cohort of a nationally representative sample of skin cancer survivors (n=862) and non-cancer adults (n=13691) ≥50 years from the US National Health and Nutrition Examination Survey. Mortality data were linked through December 31, 2019. RESULTS: During up to 13.2 years of follow-up (median, 6.3 years; 94,093 person-years), 207 deaths (cancer: 53) occurred in skin cancer survivors and 1970 (cancer: 414) in non-cancer adults. After adjusting for covariates and skin cancer type, being active was associated with lower risks of all-cause (HR=0.69; 95% CI: 0.47 to 1.00) and non-cancer (HR=0.59; 95% CI: 0.36 to 0.97) mortality compared to being inactive among skin cancer survivors. Meanwhile, sitting 8 h/d was associated with higher risks of all-cause (HR=1.72; 95% CI: 1.11 to 2.67) and non-cancer (HR=1.76; 95% CI: 1.07 to 2.92) mortality compared to sitting <6 h/d. In the joint analysis, inactive skin cancer survivors sitting >8 h/d had the highest mortality risks from all-cause (HR=2.26; 95% CI: 1.28 to 4.00) and non-cancer (HR=2.11; 95% CI,1.10 to 4.17). Additionally, the associations of LTPA and sitting time with all-cause and cause-specific mortality did not differ between skin cancer survivors and non-cancer adults (all P for interaction>0.05) CONCLUSION: The combination of prolonged sitting and lack of physical activity was associated with elevated risks of all-cause and non-cancer deaths among US skin cancer survivors. Skin cancer survivors could benefit from maintaining a physically active lifestyle.