Regular physical activity after a cancer diagnosis is linked to improved survival rates, even for individuals who were previously inactive, according to a large-scale analysis published on in JAMA Network Open. The study, which pooled data from six major long-term health studies, examined the association between leisure-time physical activity and cancer mortality across seven different cancer types: bladder, endometrial, kidney, lung, oral cavity, ovarian, and rectal.
Researchers found that even modest amounts of moderate to vigorous physical activity (MVPA) were associated with reduced cancer mortality in some cases. For bladder cancer, for example, any level of MVPA showed a significant benefit, reducing mortality risk by 33% (HR 0.67). Similar benefits were observed for endometrial cancer (HR 0.62) and lung cancer (HR 0.56) with even low levels of activity.
The study included 17,141 cancer survivors with an average age of 67. Participants reported their activity levels both before and after their cancer diagnosis, and researchers tracked mortality rates over an average of 10.9 years. Activity was measured in MET-hours per week, focusing on moderate to vigorous activity.
For ovarian cancer, the most pronounced benefit was seen at higher levels of MVPA – at least 30 MET-hours per week, which correlated with a 65% reduction in mortality risk (HR 0.35). Oral cavity and rectal cancers showed a stronger association with activity at levels exceeding standard recommendations.
Interestingly, the study also highlighted the benefits of starting to exercise after a diagnosis, even for those who weren’t active beforehand. Survivors who met recommended activity levels after their diagnosis had lower cancer mortality rates compared to those who remained inactive. Specifically, lung cancer survivors who engaged in recommended levels of MVPA had a 42% lower risk of death (HR 0.58), and those with rectal cancer saw a 49% reduction (HR 0.51).
Current recommendations suggest at least 150 to 300 minutes of moderate-intensity aerobic activity per week, or 75 to 150 minutes of vigorous-intensity activity, equating to roughly 7.5 to 15 MET-h/week. The findings suggest that even smaller amounts of activity can be beneficial, particularly for certain cancer types.
While the study demonstrates a strong association, it’s important to remember that it doesn’t prove causation. As the study authors note, this is observational research, meaning other factors could be contributing to the observed benefits. Self-reported activity levels also introduce potential for bias, as individuals may overestimate or underestimate their activity.
The study’s findings are particularly valuable because they extend beyond the more commonly studied cancers of breast, prostate, and colon. The research provides evidence supporting the importance of physical activity for a broader range of cancer survivors.
Researchers acknowledge limitations related to the study population, which was predominantly white. This limits the generalizability of the findings to more diverse populations and healthcare systems. Residual confounding factors, such as overall health status, comorbidities, and access to care, could also influence the results.
Beyond its impact on mortality, physical activity offers a range of benefits for cancer survivors, including reduced fatigue, improved functional capacity, and enhanced quality of life. The American Cancer Society recommends that healthcare providers assess and counsel patients on physical activity as soon as possible after a cancer diagnosis, tailoring recommendations to the individual’s cancer type, treatment plan, symptoms, and overall health.
Resources are available to help clinicians structure exercise prescriptions and monitor patient progress. Programs like “Prescri’Pass” offer structured adapted physical activity sessions, and online training courses are available for healthcare professionals seeking to incorporate exercise into cancer care. Varying the types of physical activity may also be beneficial, as studies suggest a link between activity diversity, and longevity.
The study was funded by the American Cancer Society, with no reported influence on the study design, analysis, or interpretation. Several authors reported research funding from the National Institutes of Health, and one author disclosed financial ties to AstraZeneca and Convergent Therapeutics.
