Physical fitness significantly improves cancer survival rates across multiple cancer types and stages, according to two major studies recently published in the British Journal of Sports Medicine. The findings provide compelling evidence that exercise should be considered an essential component of cancer care.
Fitness Components Directly Linked to Cancer Survival
A comprehensive evidence review led by Professor Robert Newton of Edith Cowan University in Australia has revealed that cancer patients with better muscle strength and cardiorespiratory fitness were 31% to 46% less likely to die prematurely from any cause. The meta-analysis pooled data from 42 previous studies involving nearly 47,000 patients with various cancer types and stages.
The researchers found a dose-response relationship between fitness and survival outcomes. Each unit increase in muscle strength lowered cancer patients' risk of death from any cause by an additional 11%, while each unit increase in cardiorespiratory fitness reduced the risk of cancer-related death by 18%.
"Muscle strength and cardiorespiratory fitness were significant predictors of all-cause mortality, especially in patients with advanced cancer," the research team concluded. This suggests that fitness assessments could potentially serve as prognostic indicators in clinical settings.
Notably, the survival benefits extended to patients with advanced-stage cancers, whose risk of early death was 8% to 46% lower with higher muscle strength and cardiorespiratory fitness. Patients with specific cancer types, including lung and gastrointestinal cancers, saw mortality risk reductions of 19% to 41%.
Pre-Diagnosis Exercise Provides Protective Effects
A separate study led by Dr. Jon Patricios from the University of the Witwatersrand in Johannesburg, South Africa, examined how pre-diagnosis exercise affects cancer progression and mortality. The researchers tracked over 28,000 people diagnosed with early-stage cancers between 2007 and 2022, with breast and prostate cancers representing 44% of cases.
The findings were striking: individuals who engaged in moderate to vigorous physical activity in the 12 months prior to their cancer diagnosis were 47% less likely to die from cancer compared to sedentary individuals. Even light exercise provided substantial benefits, reducing cancer mortality risk by 33%.
Exercise also demonstrated a protective effect against disease progression. Moderate to high levels of physical activity reduced the risk of cancer advancing to more dangerous stages by 27%, while light exercise reduced progression risk by 16%.
"Physical activity may be considered to confer substantial benefits in terms of progression and overall mortality to those diagnosed with cancer," Dr. Patricios and colleagues concluded. These protective effects persisted for up to five years after diagnosis.
Potential Mechanisms and Clinical Implications
Researchers have proposed several mechanisms by which exercise might improve cancer outcomes. Physical activity may strengthen natural immunity, enhancing the body's ability to fight cancer cells. For hormone-driven cancers like breast and prostate cancer, exercise might improve regulation of estrogen and testosterone, potentially slowing disease progression.
The findings have significant implications for clinical practice. "Our findings highlight that muscle strength could potentially be used in clinical practice to determine mortality risk in cancer patients in advanced stages and, therefore, muscle strengthening activities could be employed to increase life expectancy," noted Professor Newton's team.
Both research groups emphasized the importance of incorporating exercise recommendations into cancer care. "Implementing tailored exercise prescriptions to enhance these physical fitness components throughout the cancer continuum may contribute to reducing cancer-related mortality," wrote Newton's team.
Dr. Patricios and colleagues added, "Public health guidelines should encourage individuals to engage in physical activity to not only prevent cancer but to mitigate the risk of cancer progression."
Exercise as Medicine
These studies add to growing evidence that physical activity should be viewed as a form of medicine in cancer care. The protective effects were observed even with light exercise, suggesting that any level of physical activity is better than none.
For cancer patients and those at risk, the message is clear: pumping iron and improving cardiorespiratory fitness may significantly improve cancer outcomes. The research suggests that tailored exercise programs could become standard components of cancer treatment protocols, potentially extending and improving the lives of millions of cancer patients worldwide.
Healthcare providers may need to consider fitness assessments as part of routine cancer care and develop individualized exercise prescriptions based on patients' capabilities and cancer types. As Professor Newton's team concluded, muscle strengthening activities could be employed specifically to increase life expectancy in cancer patients.
In a world where cancer remains a significant public health burden, these findings offer hope that something as accessible as exercise could make a meaningful difference in cancer outcomes.
