CHALLENGE: Colon Health And Life Long Exercise change
A phase III study of the impact of a physical activity program on disease-free survival in patients with high risk stage II or stage III colon cancer
A clinical trial endorsed by the AGITG
The CHALLENGE trial is now running in 7 countries and has enrolled 536 of its planned 972 participants, making us more than halfway to our target. This is the world’s first large study to evaluate whether a physical activity program can improve survival in people who have had early stage colon cancer. In Australia, 186 colon cancer survivors have chosen to take part, to date. Everyone receives a regular fitness assessment and half the participants are randomised to a three-year physical activity program to help them increase their activity levels.
We know from previous research that exercise helps people feel better and maintain their physical fitness during and after treatment. But increasingly, we are seeing data that points to exercise reducing the risk of colon cancer occurring or recurring after treatment.
The exciting news is that our feasibility analysis showed that participants in the exercise group are increasing their physical activity and achieving the levels we had aimed for when planning the study. This means participants’ activity levels are reaching the amount that will hopefully reduce the chance of the cancer coming back.
How much exercise do you need?
You don’t need to turn into a gym bunny – just meeting the current health guidelines for Australian adults is enough. That means doing 150 minutes of moderate exercise or 75 minutes of vigorous exercise each week. For example, a 30-40 minute walk that makes you breathe a bit hard or sweat some, on most days of the week.
“The CHALLENGE study has shown that colon cancer survivors are willing and able to increase their physical activity and get back to exercise,” says Haryana Dhillon, “if we can provide them with support.”
How can exercise help reduce colon cancer risks?
Some risk factors for colorectal cancer include age, family history, irritable bowel disease, inactivity, obesity, high intake of calories, and consuming alcohol and processed meat. Exercise can reduce the impact of some of these factors.
Exercise can set off a number of changes in the body that can prevent damaged cells from growing abnormally and developing into a cancer. For example, with physical activity, contracting muscles make substances that reduce levels of insulin.
Exercise may help tip the balance in favour of an “anti-tumour” environment. Deep abdominal fat cells around the colon, release substances that may promote cancer cell growth. Exercise reduces the negative effects of these abdominal fat cells. When muscles contract, hundreds of anti-inflammatory substances (myokines) are released flooding the body. So the combination of anti-inflammatory effects of exercising muscle and reduced inflammation from abdominal fat could help explain why physical activity appears to be protective.
After diagnosis, many people with colon cancer reduce physical activity and most don’t return to pre-diagnosis activity levels.
“Our interim analysis data is very promising,” says Janette Vardy. “This study will be the first to answer the question of whether exercise can help reduce the risk of a cancer recurrence after chemotherapy for colon cancer. Importantly, exercise is something that almost all survivors can do that has many additional health benefits.”
CHALLENGE aims to help colon cancer survivors get back to exercise. Gloria (pictured) has been in the physical activity program for two years, and has increased her activity levels to be able to participate in 2016 Tough Mudder. With one more year to complete the program, Gloria is confident that CHALLENGE has really changed her lifestyle and she’s looking forward to more physical activity in the years ahead.
Thank you to Shelley Kay (CHALLENGE Trial Coordinator Australia), Haryana Dhillon (Co-Principal Investigator Australia) and Janette Vardy (International Study Co-Chair and Co-Principal Investigator Australia) for contributing this article.