Exercise Saves Lives! Striking Results from a 15-Year Colon Cancer Study

Exercise as a Cancer Drug

Colon cancer is the world's third most common cancer and the second leading cause of cancer-related death. In Stage 3 or high-risk Stage 2 disease, despite surgery followed by adjuvant (preventive) chemotherapy, the disease recurs in 20% to 40% of patients. A new strategy to prevent recurrence is greatly needed for this group.

One of the Most Notable Studies at ASCO 2025

At the 2025 ASCO meeting, Dr. Christopher Booth presented the LBA3510 abstract, reporting findings simultaneously published in NEJM from the CHALLENGE study, which offered potentially groundbreaking findings for colon cancer treatment.

Previous observational studies suggested that physical activity might reduce recurrence risk in colon cancer, but could not establish causality. To address this scientific gap, the Canadian Cancer Trials Group led CHALLENGE (Colon Health and Life-Long Exercise Change) , a phase 3 randomized clinical trial evaluating the effects of a structured exercise program after adjuvant chemotherapy on disease-free and overall survival .

This rigorous research, spanning 15 years, drew attention not only for its survival outcomes but also for its effects on quality of life. Perhaps for the first time, an exercise program demonstrated a “drug-like” effect in colon cancer.

📚 Study Design: Who Received What?

• Number of participants: 889 patients
• Target population: Patients with Stage 3 or high-risk Stage 2 colorectal cancer
• Median age: 61
• Proportion of women: 51%
• Completed adjuvant chemotherapy: FOLFOX (the majority), CAPOX
• Randomization:
  • Exercise Group (445 patients): Structured exercise for 3 years
  • Health Education Group (444 patients): Information booklets only

What Did the Exercise Involve?

After completing adjuvant chemotherapy, patients in the exercise group were supported by physical activity consultants through a structured 3-year program. Its main goal was to increase weekly activity above baseline by at least 10 MET-hours (approximately equivalent to 150–180 minutes of brisk walking per week) through moderate- or higher-intensity aerobic exercise . Recommended activities included brisk walking, cycling, light jogging, or swimming . Participants were motivated through regular follow-up to achieve and maintain this goal, and exercise plans were individualized when needed.

📈 Results in Numbers: Significant Improvement in Survival

🧬 Disease-Free Survival (DFS)

Annual event rate: 3,7% in the exercise group and 5.4% in the control group

❤️ Overall Survival (OS)

📌 Exercise reduced the risk of death by 37%.

💪 Clear Improvement in Function

Patients in the exercise group had significantly better physical functioning at every time point:

• At month 6 SF-36 physical functioning score:
  • Exercise group: +7.1-point increase
  • Control group: +1.3-point increase
  • Difference: +5.8 points
• At year 3 SF-36 score:
  • Exercise group: +6.1-point increase
  • Control group: +3.0-point increase
  • Difference: +3.1 points

Additional physical gains:

• 6-minute walking distance: in the exercise group, an average increase of +30 meters was observed
• VO₂ max (cardiorespiratory capacity): in the exercise group, +2.7 mL/kg/min was the increase

🤠 Mechanism: Why Does Exercise Help?

• Lower insulin and IGF levels
• Suppression of inflammation
• Activation of the immune system
• Suppression of the microarchitecture of metastasis
• Reduced tumor angiogenesis

Marked reductions were observed particularly in liver recurrences (3.6% vs. 6.5%) and new primary cancers (5.2% vs. 9.7%).

⚠️ Safety: What Were the Risks?

• Any adverse event: 82% in the exercise group
• Musculoskeletal events: 18.5% (only 1.8% were serious)
• Grade 3+ adverse events: 15.4% in the exercise group

These adverse events can be reduced through individualized programs.

🖯️ Clinical Message and Recommendations

• Exercise should be part of standard care in colon cancer treatment
• Behavior-change support is essential
• Health policies should invest in this area

✍️ A Final Thought

The CHALLENGE study shows that exercise after colon cancer both prolongs survival and improves quality of life. Exercise is now more than a recommendation: it is an evidence-based treatment step.