Inflammation, Physical Activity, and Disease-Free Survival in Stage III Colon Cancer: CALGB/SWOG 80702 (Alliance).

Background: Both inflammation and insufficient physical inactivity contribute to individual-level risk of disease recurrence and death in stage III colon cancer. The extent to which increased inflammatory risk can be offset by sufficient physical activity remains unknown.

Methods: This cohort study was nested within the CALGB/SWOG 80702 (Alliance) randomized trial. Inflammatory burden was quantified by high-sensitivity C-reactive protein, interleukin-6, and soluble tumor necrosis factor-α receptor 2 after recovery from tumor resection. Physical activity was measured during and after postoperative chemotherapy. The primary endpoint was disease-free survival.

Results: The 3-year disease-free survival rate was 88.4% among patients with low inflammation and sufficient physical activity (referent group for all comparisons), 84.9% with low inflammation and insufficient physical activity [absolute risk difference (RD): -3.5%, 95% Confidence Interval (CI): -11.3, 4.3; P = .38], 78.0% with intermediate inflammation and insufficient physical activity (RD: -10.4%, 95% CI: -17.4, -3.3; P = .007), and 79.7% with high inflammation and insufficient physical activity (RD: -8.7%, 95% CI: -15.7, -1.6; P = .022). In contrast, the 3-year disease-free survival rate was 87.3% among patients with intermediate inflammation and sufficient physical activity (RD: -1.1%, 95% CI: -7.5, 5.3; P = .74) and 84.4% with high inflammation and sufficient physical activity (RD: -4.0%, 95% CI: -12.3, 4.3; P = .34).

Conclusion: In this observational study of stage III colon cancer patients, physical activity was associated with improved disease-free survival despite high inflammation. Patients with intermediate or high inflammation who were physically active had disease-free survival rates that were not statistically significantly different from those with low inflammation.