A groundbreaking new study published in Journal of the National Cancer Institute (JNCI) reveals that engaging in regular physical activity after a cancer diagnosis significantly boosts survival across multiple cancer types. Conducted by researchers from institutions including the American Cancer Society and Harvard, this pooled analysis examined over 90,000 cancer survivors from six U.S. cohort studies—making it one of the largest and most comprehensive analyses to date.
The study focused on leisure-time moderate-to-vigorous physical activity (MVPA), such as brisk walking or cycling, completed at least one year after diagnosis to avoid the confounding effects of initial cancer treatments. Participants were followed for an average of 10.9 years. The results were striking. Survivors who met the current MVPA recommendations (7.5-15 MET-hours/week) had a markedly lower risk of death compared to inactive individuals.
What is a MET? A METs is a Metabolic Equivalent Task. 1 MET is the energy expended at rest (sitting quietly). Activities are assigned MET values to represent how much energy they use compared to resting. As an example, walking briskly is roughly 3 to 4 METs. Jogging would be the equivalent of approximately 7 METs.
7.5 MET-hours/week is the equivalent of 150 minutes moderate-intensity exercise like brisk walking. 15 MET-hours/week is the equivalent of 300 minutes of moderate-intensity or 150 minutes of vigorous activity.
Specifically, physical activity after diagnosis was associated with improved overall survival in ten major cancer types: oral cavity, endometrial, lung, rectal, respiratory, bladder, kidney, prostate, colon, and breast cancer. The hazard ratios for mortality ranged from 0.44 to 0.67, indicating up to a 56% reduced risk of death in some groups. For lung cancer survivors, the risk of death was nearly halved among those who were physically active.
Importantly, the study showed benefits not only for meeting physical activity guidelines, but also for those who engaged in less than the recommended amount—suggesting that even modest activity levels confer survival advantages. Furthermore, survivors who exceeded the guidelines (up to ≥30 MET-hours/week) experienced additional, albeit modest, reductions in mortality risk.
This analysis also provided the first longitudinal evidence linking postdiagnosis physical activity to improved survival in survivors of bladder and oral cavity cancers, and is the largest study to date for endometrial, kidney, and lung cancer survivors. These findings close a significant gap in the literature, which until now primarily focused on breast and colorectal cancers.
To ensure that the results were robust, the researchers conducted sensitivity analyses. The study made adjustments for factors like smoking, body mass index, treatment, and cancer stage. Most findings held strong, suggesting the observed associations were not merely due to healthier individuals being more likely to exercise.
What makes this study particularly impactful is its potential to change clinical practice. For many cancer survivors, the postdiagnosis period can serve as a “teachable moment”—a time when patients are more open to adopting healthy behaviors. This research reinforces the importance of integrating physical activity into survivorship care plans.
Despite its strengths, the study does have limitations. Physical activity was self-reported, which can introduce bias, and cancer recurrence or progression data were not consistently available across cohorts. Nevertheless, the harmonized methodologies and large sample size lend significant credibility to the conclusions.
In summary, this major analysis confirms that physical activity after cancer diagnosis is a powerful predictor of survival. The message for survivors and healthcare providers is clear: move more, live longer. Encouraging and supporting exercise should be a core component of oncology care, not just for quality of life, but also for quantity of life.
JNCI: Journal of the National Cancer Institute, djaf112, https://doi.org/10.1093/jnci/djaf112
