Study finds simple exercise can bring down recurrence of colon cancer down by over one-third

A new phase 3 clinical trial has found that regular, moderate exercise significantly reduces the risk of colon cancer recurrence — an observation rivaling the effects of some chemotherapy treatments. 

The study, published in the New England Journal of Medicine, showed that patients who engaged in structured exercise after surgery and chemotherapy had a 28 per cent lower risk of cancer recurrence, new cancers, or death over an eight-year period compared to those who only received health education.

The trial, conducted in Canada, involved 855 participants who had been treated for colon cancer. One group received coaching and supervision for a structured exercise program lasting three years, while the other group was provided with general health education. 

According to the study, after five years, 80.3 per cent of those in the exercise group remained cancer-free, compared to 73.9 per cent in the education group — a 6.4 percentage-point improvement. 

The overall eight-year survival rate was 90.3% in the exercise group, compared to 83.2 per cent in the control group, marking a 7.1 percentage-point difference. 

The relative risk of death was reduced by 37 per cent among exercisers.

The exercise routines were moderate and accessible — typically including brisk walking or jogging, amounting to about 20 MET (Metabolic Equivalent of Tasks) hours per week.

One hour of brisk walking (4 METs) or 30 minutes of jogging (10 METs) performed multiple times a week was enough to produce measurable benefits. The intervention also improved cardiorespiratory fitness and physical functioning.

Colon cancer is the third most common cancer worldwide and a leading cause of cancer-related death. According to the World Health Organisation, over 1.9 million cases of colorectal cancer are diagnosed annually, and it causes approximately 935,000 deaths each year across the globe. 

In India, the Global Cancer Observatory (GLOBOCAN 2020) reported around 72,000 new colorectal cancer cases and over 49,000 deaths in a year.

While the precise biological mechanisms behind exercise's cancer-fighting power remain under investigation, scientists believe it may enhance immune response, reduce inflammation, improve insulin sensitivity, and alter the environment where metastases typically form. 

Researchers also found that exercise helped prevent not only recurrent colon cancer but also other cancers like breast and prostate.

"This indicates that exercise has a similarly strong effect as previously shown for chemotherapy, which is really quite impressive," said Marco Gerlinger, a gastrointestinal cancer expert at Queen Mary University of London, according to Ars Technica.

Oncologists, the study's authors suggest, can now confidently recommend structured exercise as part of post-treatment care for colon cancer patients.