Strengthening the body to prevent colon cancer from returning

Clinical trials don’t always set out to prove whether drugs are effective. They can also test surgeries, radiation therapy, or even exercise. Dr. Christopher Booth was a CCTG research fellow in 2006 when results of a 30-year study in the United States noted that the nurses who exercised were less likely to contract colon cancer. Even more interesting was that those who contracted colon cancer and exercised were less likely to relapse. As a colon cancer specialist, Dr. Booth was intrigued and he suggested a trial that would attempt to further prove the American study’s findings.

“There’s lots of literature showing that if you exercise, your chance of getting cancer is lower,” Dr. Booth says. “Other studies show that if you have cancer and you exercise, your fatigue might improve and your quality of life might improve.”

The Challenge Trial (C0.21) opened in 2009 with patients across Canada, the US, the UK, Australia, Israel, and South Korea. Dr. Booth’s trial was the first to ask the specific question: Will exercise help prevent colon cancer from coming back?

Dr. Booth says his question is a little different. “We’re not trying to prove that exercise is safe,” he says. “In order to change practice, we need to prove that exercise increases cure rates. If we really want people to change their lifestyles, we’ll probably need to embed personal trainers in the cancer centres as part of the treatment team, and no one is going to do that if there isn’t data to show that it makes a difference.”

After chemotherapy, participating patients are randomly placed in one of two groups. One group gets the current standard of care, which Dr. Booth describes as “a book that tells you to eat well and exercise.” The other is assigned a personal trainer for three years. “They work with patients to come up with an exercise prescription to keep them motivated and moving. Most people end up walking briskly four times a week for 30 or 40 minutes,” says Dr. Booth.

Early results are encouraging. “It’s doing what we had hoped,” Dr. Booth says. “The patients who have the trainer are exercising more than the ones who got the book.” This is a critical step, because in order to prove that exercise can improve survival, patients actually have to exercise.

Just as importantly, Dr. Booth knows that a successful trial could persuade more people to exercise.

“Some people just don’t like exercising,” he says, “but if there’s a clinical trial showing that it increases survival by the same order of magnitude as say chemotherapy, they might reconsider.”