Impact of physical activity after cancer diagnosis on survival in patients with recurrent colon cancer: Findings from CALGB 89803/Alliance.

BACKGROUND: The impact of physical activity on survival outcomes in patients with recurrent colon cancer has not been studied. We tested the association between the level of postdiagnosis physical activity and survival outcomes of patients with recurrent colon cancer. PATIENTS AND METHODS: We conducted a prospective observational study of 237 patients with stage III colon cancer who had recurrence of disease. Physical activity was measured approximately 6 months after the completion of therapy (14 months after surgical resection) but before detection of recurrent disease. The primary end point of the study was survival time after recurrence. RESULTS: The hazard ratio comparing patients who reported at least 18 metabolic equivalent task (MET) hours per week of physical activity with those engaging in < 3 MET hours per week was 0.71 (95% confidence interval, 0.46-1.11). Increasing total MET hours of physical activity per week was associated with a borderline statistical significance trend for improved survival after recurrence (P = .052). The benefit of physical activity on survival was not significantly modified by sex, body mass index (BMI), number of positive lymph nodes, age, baseline performance status, adjuvant chemotherapy regimen, or recurrence-free survival period. CONCLUSION: To our knowledge, this is the first study investigating the association of physical activity with survival outcome of patients with recurrent colon cancer. Although the association exceeded our predefined P trend < .05 for statistical significance, these findings warrant further studies of physical activity in patients with recurrent colorectal cancer.

Dietary glycemic load and cancer recurrence and survival in patients with stage III colon cancer: findings from CALGB 89803.

BACKGROUND: The influence of glycemic load and related measures on survival among colon cancer patients remains largely unknown. METHODS: We conducted a prospective, observational study of 1011 stage III colon cancer patients reporting dietary intake during and 6 months after participation in an adjuvant chemotherapy trial. We examined the influence of glycemic load, glycemic index, fructose, and carbohydrate intakes on cancer recurrence and mortality using Cox proportional hazards regression; all tests of statistical significance were two-sided. RESULTS: Stage III colon cancer patients in the highest quintile of dietary glycemic load experienced an adjusted hazard ratio (HR) for disease-free survival of 1.79 (95% confidence interval [CI] = 1.29 to 2.48), compared with those in the lowest quintile (P (trend) across quintiles <.001). Increased glycemic load was associated with similar detriments in recurrence-free (P (trend) across quintiles <.001) and overall survival (P (trend) across quintiles <.001). These associations differed statistically significant by body mass index (BMI) (P (interaction) =.01). Whereas glycemic load was not associated with disease-free survival in patients with BMI < 25kg/m(2), higher glycemic load was statistically significant associated with worse disease-free survival among overweight or obese participants (BMI ≥ 25kg/m(2); HR = 2.26; 95% CI = 1.53 to 3.32; P (trend) across quintiles <.001). Increasing total carbohydrate intake was similarly associated with inferior disease-free, recurrence-free, and overall survival (P (trend) across quintiles <.001). CONCLUSION: Higher dietary glycemic load and total carbohydrate intake were statistically significant associated with an increased risk of recurrence and mortality in stage III colon cancer patients. These findings support the role of energy balance factors in colon cancer progression and may offer potential opportunities to improve patient survival.