Association between recorded physical activity and cancer progression or mortality in individuals diagnosed with cancer in South Africa
Objectives This study aimed to determine the association between progression and mortality in individuals with stage 1 cancer and their recorded physical activity before the diagnosis of the cancer. Methods We included 28 248 members with stage 1 cancers enrolled in an oncology programme in South Africa. Physical activity was recorded using fitness devices, logged gym sessions and participation in organised fitness events. Levels of physical activity over the 12 months before cancer diagnosis were categorised as no physical activity, low physical activity (an average of <60 min/week) and moderate to high physical activity (≥60 min/week). Measured outcomes were time to progression, time to death and all cause mortality. Results Physically active members showed lower rates of cancer progression and lower rates of death from all causes. The HR for progression to higher stages or death was 0.84 (95% CI 0.79 to 0.89), comparing low activity with no physical activity, and 0.73 (95% CI 0.70 t