Improper sedentary behavior is often linked with an increased risk of cancer mortality in adults, especially middle-aged and older adults. This study aims to examine the association between sedentary behavior and the risk of cancer mortality.

This is a prospective cohort study that included a total of 8,002 US adults aged 45 or more. Out of the total participants, 3,668 were men, and 4,334 were women. The participants were assessed on their sedentary time, light-intensity physical activity (LIPA), and moderate- to vigorous-intensity physical activity (MVPA) for seven days using a hip-mounted accelerometer. The primary outcome of the study was cancer mortality.

During a mean follow-up of 5.3 years, 268 participants (3.3%) died of cancer. Multivariable-adjusted models suggested a positive association between sedentary time and a greater risk of cancer mortality. Replacing 30 minutes of LIPA was associated with an 8% decrease in the risk of cancer mortality, and MVPA was associated with a 31% lower risk of cancer mortality.

This cohort study concluded that greater sedentary time, as measured by accelerometry, is strongly associated with a higher risk of cancer mortality. The findings also suggested a strong positive association between 30 minutes of LIPA and MVPA and a lower risk of cancer mortality.