Importance: The American Cancer Society Nutrition and Physical Activity Guidelines for Cancer Survivors (ACS guidelines) include maintaining (1) a healthy body weight; (2) physical activity; and (3) a diet that includes vegetables, fruits, and whole grains. It is not known whether patients with colon cancer who follow these guidelines have improved survival.
Objective: To examine whether a lifestyle consistent with the ACS guidelines is associated with improved survival rates after colon cancer.
Design, setting, and participants: This prospective cohort study included 992 patients with stage III colon cancer who were enrolled in the CALGB 89803 randomized adjuvant chemotherapy trial from 1999 through 2001. Data for the present study were analyzed between November 2016 and December 2017.
Exposures: We assigned an ACS guidelines score for each included patient based on body mass index; physical activity; and intake of vegetables, fruits, whole grains, and red/processed meats (score range, 0-6, with higher score indicating healthier behaviors). Secondarily, we examined a score that also included alcohol intake in addition to the other factors (range, 0-8). Lifestyle was assessed during and 6 months after chemotherapy.
Main outcomes and measures: Hazard ratios (HRs) and 95% confidence intervals (CIs) for disease-free, recurrence-free, and overall survival.
Results: Of the 992 patients enrolled in the study, 430 (43%) were women, and the mean (SD) age was 59.6 (11.2) years (range, 21-85 years). Over a 7-year median follow-up, we observed 335 recurrences and 299 deaths (43 deaths without recurrence). Compared with patients with a 0 to 1 ACS guidelines score (n = 262; 26%), patients with a 5 to 6 score (n = 91; 9%) had a 42% lower risk of death during the study period (HR, 0.58; 95% CI, 0.34-0.99; P = .01 for trend) and improved disease-free survival (HR, 0.69; 95% CI, 0.45-1.06; P = .03 for trend). When alcohol consumption was included in the score, the adjusted HRs comparing patients with scores of 6 to 8 (n = 162; 16%) vs those with scores of 0 to 2 (187; 91%) were 0.49 for overall survival (95% CI, 0.32-0.76; P = .002 for trend), 0.58 for disease-free survival (95% CI, 0.40, 0.84; P = .01 for trend), and 0.64 for recurrence-free survival (95% CI, 0.44-0.94; P = .05 for trend).
Conclusions and relevance: Having a healthy body weight, being physically active, and eating a diet rich in vegetables, fruits, and whole grains after diagnosis of stage III colon cancer was associated with a longer survival.
Trial registration: clinicaltrials.gov Identifier: NCT00003835.