Exercise extends life for people with cancer, study shows

NEW YORK – A first-of-its-kind study adds powerful new evidence to research showing that exercise improves cancer survival.

The study, a randomised controlled trial of nearly 900 patients at 55 cancer centres in six countries, showed that people who participated in a structured exercise programme lived longer without their cancer coming back and without the occurrence of new cancers.

Participants in the exercise programme had a 37 per cent lower risk of dying and a 28 per cent lower risk of recurrent or new cancer than those in the control group.

Earlier research had suggested such a benefit, but the data was from observational studies that did not prove a causal link, experts said.

“We now have definitive evidence that exercise is not just an intervention for quality of life and fitness. This is an intervention that improves survival and should be standard of care,” said Dr Christopher Booth, the senior author of the paper and a professor of oncology at Queen’s University in Canada.

The study, which was published in the New England Journal of Medicine recently, looked at patients with Stage III or high-risk Stage II colon cancer, who received standard surgery and chemotherapy treatment.

Researchers randomly assigned these patients to a control group, which received educational materials promoting physical activity and healthy nutrition, or to a treatment group, which also received support from a “physical activity consultant” – a hybrid of personal trainer and life coach – over three years to increase their aerobic exercise and sustain it.

Patients could choose a number of activities, such as biking, jogging, swimming or kayaking, but most opted for a brisk walk of 45 minutes four times a week, Dr Booth said.

Eighty per cent of patients in the exercise group remained disease-free after five years, compared with 74 per cent of patients in the control group. After eight years, the exercise programme had prevented one death for every 14 people who participated in the exercise arm of the study.

The reduction was specifically in colon cancer deaths, Dr Booth said – not deaths from other causes, like cardiovascular disease.

“This is really wonderful news, particularly at a time when colon cancer rates are increasing among younger adults,” said Dr Michelle Holmes, a professor of medicine at Harvard University who has studied lifestyle interventions to improve cancer survival and was not involved in the new study.

She added that the improvement in disease-free survival was “in the same ballpark” as what observational studies across a range of cancers have shown, suggesting that the benefit of exercise extends beyond colon cancer.

Typically, colon cancer patients receive surgery and chemotherapy and then are sent home and followed intermittently, with loose guidance to exercise and follow a healthy lifestyle. “Essentially, we would just cross our fingers and hope the cancer doesn’t come back,” Dr Booth said.

But in 30 to 40 per cent of patients, it does. Doctors said patients often ask what they can do after treatment to improve their outcomes.

“Clearly, an exercise programme has to be right on that menu of things that we’re offering people as part of really routine care,” said Dr Graham Colditz. The epidemiologist and associate director for prevention and control at the Alvin J. Siteman Cancer Center at Washington University was not involved in the study.

It is not clear how exactly exercise reduces the new onset or recurrence of cancer.

Weight loss was the same between the two trial groups, Dr Booth said, so that does not appear to be the driver.

But researchers have long shown that exercise improves insulin sensitivity and reduces inflammation. The researchers collected blood samples and will analyse them to shed light on whether these factors might be driving the improved survival.

Of course, the real-world impact of such an intervention will depend on how many people can take up and stick with an exercise programme. This was a clinical trial in which patients were slightly younger and healthier than the typical cancer patient might be, and they were also already motivated to exercise. Even the control group increased their exercise levels, Dr Booth said, though the treatment group increased them by much more.

Involving patients in a structured exercise programme with ongoing support and accountability was key, said lead author Kerry Courneya of the paper, a professor and Canada research chair in physical activity and cancer at the University of Alberta.

The programme included 48 sessions with a physical activity consultant over three years. The consultant helped troubleshoot problems, supported patients to find time to exercise and make it fun, and periodically assessed their physical fitness. The estimated total cost of each patient was between US$3,000 (S$3,830) and US$5,000, depending on the centre, Dr Booth said.

Ms Terri Swain-Collins, a trial participant, said that when she began, knowing she would be meeting a consultant every two weeks forced her to stay on top of the exercise.

“I was like, I’m doing this because I can’t go see her and not have done this,” she said. “If I hadn’t had that, I wouldn’t have done it.” NYTIMES