Survivors of colorectal cancer who exercised for at least 1 hour per week and had a low body fat mass were found to have lower rates of colorectal polyp recurrence, according to a study published in Cancer Prevention Research.

Obesity is known to increase the risk of tumor growth, including colorectal cancer and colorectal polyps. Conversely, the results of previous studies suggest that exercise may decrease this risk.

For this study, 300 patients who had survived colorectal cancer were randomly selected and followed for 5 years or more. All patients had undergone curative resection, and underwent a baseline colonoscopy prior to surgery or within 6 months after resection.  

Study patients reported their various levels of physical activity by completing the Global Physical Activity Questionnaire (GPAQ), and were stratified into an active group which reported exercising for more than 1 hour/week and a sedentary group who reported less than 1 hour/week.  Patients had their body composition analyzed and underwent surveillance colonoscopy.

The active group had a significantly lower rate of advanced adenoma recurrence compared with the sedentary group (6.4% vs 14.4%; P =.023), and this reduction was dose dependent on exercise (Ptrend =.019). There was, however, no significant difference for overall adenoma recurrence (33.5% vs 29.9%, P =.533).

Body fat mass (odds ratio [OR], 7.601; 95% CI, 1.583-36.485; P =.011) and active exercise (OR, 0.340; 95% CI, 0.143-0.809; P =.015) were found to be independent factors associated with advanced polyp recurrence in a multivariate logistic analysis.

Body fat mass (hazard ratio [HR], 5.315; 95% CI, 1.173-24.083; P =.030) and active exercise (HR, 0.367; 95% CI, 0.162-0.833; P =.017) were found to be independent factors associated with cumulative advanced adenoma recurrence in Cox proportional hazards models.

Study authors conclude “that high body fat mass and low physical activity are meaningful independent risk factors of advanced adenoma recurrence in colorectal cancer survivors after treatment, suggesting the importance of exercise amount for the prevention of colorectal neoplasia.”

Reference

1. Park J, Kim JH, Lee HJ, et al. The effects of physical activity and body fat mass on colorectal polyp recurrence in patients with previous colorectal cancer [published online July 7, 2017]. Cancer Prev Res. doi: 10.1158/1940-6207.CAPR-17-0065