Recent research highlights the profound benefits of exercise in combatting colon cancer, suggesting it can rival the effectiveness of some chemotherapy treatments. This conclusion stems from a phase 3, randomized clinical trial conducted in Canada, which evaluated nearly 900 individuals who had previously undergone surgery and chemotherapy for colon cancer.
Participants in the study were divided into two groups. One group participated in an enhanced exercise program over three years, which included coaching and supervision, while the other group received general health education. The results were compelling: the exercise group experienced a 28 percent reduction in the risk of colon cancer recurrence, new cancer development, or death over an impressive eight-year follow-up period compared to the health education group.
The findings, published in the New England Journal of Medicine, revealed that the benefits of exercise became evident within just one year and continued to amplify over time. Notably, the five-year survival rate for the exercise group was 80.3 percent, showing a significant 6.4 percentage-point increase over the education group's 73.9 percent cancer-free survival rate. Additionally, the overall survival rate during the study's duration was 90.3 percent among those who exercised, compared to 83.2 percent in the education group, marking a 7.1 percentage-point difference.
The study also indicated that exercise led to a 37 percent reduction in the relative risk of death, with only 41 participants in the exercise group succumbing during the study, compared to 66 in the health education group. The researchers noted that the benefits derived from exercise were comparable to several currently approved standard drug treatments.
Interestingly, the exercise routines that produced these significant benefits were not overly strenuous. Participants were encouraged to engage in recreational aerobic activities they enjoyed, such as brisk walking. Incorporating 45 to 60 minutes of brisk walking three to four times a week, or jogging for 25 to 30 minutes on similar frequency, sufficiently improved participants' odds of survival. The primary goal was to achieve over 20 MET hours per week, a measure of energy expenditure.
To reach this target, individuals could engage in five hours of brisk walking weekly or jog for two hours weekly. For reference, brisk walking is estimated to be around four METs, while jogging is about ten METs.
The exercise group, which benefited from supervised sessions during the initial six months of the intervention, reported higher levels of physical activity throughout the study. By the trial's conclusion, they averaged over 20 MET hours per week, compared to approximately 15 MET hours for the education group. Moreover, those in the exercise group also showed improvements in cardiorespiratory fitness and overall physical functioning.
While the control group also exhibited an increase in physical activity, starting from an average of 10 MET hours per week, these findings suggest that the impact of exercise on cancer outcomes may be even more substantial when compared to a completely sedentary control group.
Despite the promising results, the precise mechanisms by which exercise aids in cancer prevention remain unclear. Nonetheless, these findings align with numerous observational studies linking physical activity to improved outcomes in cancer patients. Potential hypotheses include enhanced immune function, reduced inflammation, improved insulin sensitivity, and alterations to the microenvironment of major metastasis sites.
Experts in the field have lauded the study's findings. Marco Gerlinger, a gastrointestinal cancer expert at Queen Mary University of London, stated that the results indicate a remarkably strong effect of exercise, akin to that of chemotherapy. David Sebag-Montefiore, a clinical oncologist at the University of Leeds, remarked on the significance of providing patients with evidence-based recommendations for reducing cancer recurrence risk. He emphasized that this breakthrough is a pivotal step in enhancing cure rates for colon cancer.
Overall, the appeal of a structured, moderate-intensity exercise program lies in its ability to deliver substantial health benefits without the adverse side effects commonly associated with traditional cancer treatments.
