Association of Physical Activity Intensity with All-Cause Mortality in Cancer Survivors: A National Prospective Cohort Study

SIMPLE SUMMARY: Insufficient physical activity (PA) is a global health issue with significant disease burden. Increasing evidence suggests that higher PA levels have protective effects against chronic diseases. Few prospective cohort studies have explored the association between PA levels and mortality in cancer survivors. Using a large nationally representative survey population of United States adults, this study demonstrated a beneficial association between leisure-time PA and all-cause mortality in cancer survivors. There was a nonlinear relationship between the total PA and the risk of all-cause mortality. Threshold effect analysis demonstrated that cancer survivors should perform PA for at least 1 h per week and performing more PA could provide additional survival benefits for cancer survivors. ABSTRACT: We designed this study to investigate the associations between physical activity (PA) and the risk of all-cause mortality in cancer survivors using a nationally representative cohort of US adults. This cohort study included 13 cycles of the National Health Interview Surveys, and by matching participants with the National Death Index (2015), survival status was determined. The main outcome was all-cause mortality during follow-up. A total of 20,088 participants aged 62.2 (15.9) years (62.4% women) were analyzed. After an average follow-up of 117.5 months, 7214 (35.9%) participants died. Compared with inactive cancer survivors, we observed a 25% lower all-cause mortality risk among participants performing PA 10 min to 1 h/week (hazard ratio [HR] = 0.75, 95% confidence interval [CI] = 0.67–0.85), a 28% lower risk among those performing PA 1–2.5 h/week (HR = 0.72, 95% CI = 0.67–0.78), a 34% lower risk among those performing PA 2.5–5 h/week (HR = 0.66, 95% CI = 0.60–0.72), a 37% lower risk among those performing PA 5–7.5 h/week (HR = 0.63, 95% CI = 0.56–0.70), a 47% lower risk among those performing PA 7.5–13.3 h/week (HR = 0.53, 95% CI = 0.47–0.61), and a 43% lower risk among those performing PA 13.3–24 h/week (adjusted HR = 0.53, 95% CI = 0.49–0.66). In cancer survivors, leisure-time PA was associated with a lower all-cause mortality. Inactive cancer survivors should be encouraged to perform more PA to reduce the risk of all-cause mortality.