A groundbreaking international study has found that a three-year structured exercise program cut the risk of death in colon cancer patients by 37% and reduced the chance of cancer recurrence by 28%.
The study, published in the New England Journal of Medicine and presented at the ASCO oncology conference in Chicago, is the first to offer clear evidence that physical activity alone—without medication—can significantly improve survival and prevent recurrence in colon cancer patients.
Researchers followed 889 patients in six countries—Canada, Australia, the UK, Israel, France and the U.S.—between 2009 and 2024. All participants had undergone surgery for stage III colon cancer and completed chemotherapy.
Half were randomly assigned to receive educational materials about exercise and diet. The other half participated in a supervised fitness program that included biweekly meetings with a trainer for the first year, followed by monthly sessions for the next two.
The program included three to four weekly 45–60 minute walks but participants were allowed to choose other forms of activity, such as kayaking or skiing. In the structured exercise group, participants not only became more physically active but also had significantly better outcomes. After eight years, their overall mortality dropped by 37% compared to the control group and their risk of recurrence fell by 28%.
Among the participants were eight Israelis aged 60–78, enrolled through Shamir Medical Center under the oversight of Dr. Nirit Yarom, head of chemotherapy at the hospital’s oncology institute and a senior lecturer at Tel Aviv University.
Dr. Nirit YaromPhoto: Shamir Medical Center“These are very impressive results,” Dr. Yarom said in an interview with Ynet. “It’s not surprising that exercise improves fitness but the fact that it reduces cancer recurrence and increases survival is remarkable.”
She stressed that while previous studies hinted at the benefits of exercise in cancer care, none had proven causality. “This is the first time a study shows that exercise alone—independent of medication—impacts recovery from cancer,” she said.
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The study was not backed by pharmaceutical companies but was led by Canada’s health research authority. In Israel, it was supported by the Israel Cancer Association, which provided a NIS 200,000 ($56,780) research grant.
Dr. Julie Gralow, chief medical officer of the American Society of Clinical Oncology (ASCO), praised the study’s quality: “This is about the highest-quality evidence you can get. I love this study.” She noted that earlier research comparing sedentary and active individuals couldn't prove a direct cause-and-effect relationship.
Participants in the supervised group received a structured regimen that included aerobic and resistance training, as well as incline-based workouts. Kingston, Ontario resident Terri Swain-Collins, 62, was one of the participants. “It was something I could do for myself to feel better,” she said.
Maintaining regular contact with a supportive trainer helped her stay motivated. “I didn’t want to show up and say, ‘I didn’t do anything.’ So I made sure I did.” Swain-Collins has continued exercising since the program ended and now walks through the countryside while listening to music.
“When we saw the results, we were stunned,” said co-author Dr. Christopher Booth, an oncologist at Kingston Health Sciences Centre in Ontario. “A relatively inexpensive intervention helps people feel better, suffer fewer recurrences and live longer.”
Researchers are still exploring the biological mechanisms linking exercise to reduced cancer risk—possibly involving insulin processing or immune system enhancements.
“This is a tremendously exciting study,” said Dr. Jeffrey Meyerhardt of the Dana-Farber Cancer Institute in Massachusetts, who was not involved in the study. “It’s the first randomized controlled trial to show that exercise reduces recurrence and improves survival.”
Prof. Kerry Courneya of the University of Alberta, a co-author of the study, noted that behavior change is more likely when people believe in the benefits, enjoy the activity and feel socially supported. “We can now say unequivocally that exercise improves survival,” he said.
Experts are urging cancer centers and insurers to consider incorporating exercise training as a standard part of care for colon cancer survivors. “Exercise is now very accessible,” said Dr. Yarom.
“The future is in the clinic, where we already have some of the infrastructure in place.” At Shamir Medical Center, she noted, physical therapists already support recovering patients and the Israel Cancer Association runs a project promoting physical activity among survivors.
“Thanks to this study,” she said, “we’ll be in a much stronger position to persuade patients to exercise after treatment.” Until then, she added, patients can increase their activity levels knowing they’re doing their part to help prevent the cancer from returning.