Adherence to the World Cancer Research Fund/American Institute for Cancer Research Cancer Prevention Recommendations and Colorectal Cancer Survival.

Abstract

Patients with cancer are recommended to follow cancer prevention guidelines due to inadequate evidence for specific recommendations for cancer survivors. We examined whether diet and lifestyle scores measuring adherence to the 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention guidelines were associated with colorectal cancer-specific and overall mortality among 1,491 patients with colorectal cancer in two prospective cohorts. Cox proportional hazards regression models were used to calculate the multivariable-adjusted HRs and 95% confidence intervals (CI). During a median follow-up of 7.92 years, there were 641 deaths (179 colorectal cancer-specific deaths). Patients in the highest quartile of the post-diagnostic WCRF/AICR lifestyle score including diet, body mass index (BMI), and physical activity had a 24% lower risk (HR = 0.76, 95% CI: 0.49-1.18) of colorectal cancer-specific mortality and a 37% lower risk (HR = 0.63, 95% CI: 0.50-0.78) of overall mortality compared with the lowest quartile. When BMI was not included in the lifestyle score due to potential disease-related weight loss, stronger inverse associations were observed for both colorectal cancer-specific and overall mortality for the same comparison (colorectal cancer-specific: HR = 0.50, 95% CI: 0.32-0.79; overall: HR = 0.59, 95% CI: 0.47-0.75). The post-diagnostic WCRF/AICR diet score was not statistically significantly associated with either colorectal cancer-specific or overall mortality. Greater adherence to the WCRF/AICR cancer prevention recommendations was associated with improved survival in patients with colorectal cancer. This study provides support for patients with colorectal cancer to follow cancer prevention recommendations after diagnosis. Future studies on cancer survivors will continue to contribute to evidence-based diet and lifestyle recommendations for patients with cancer.