Cancer patients 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 colorectal cancer (CRC) patients in two prospective cohorts. Cox proportional hazards regression models were used to calculate the multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).
During a median follow-up of 7.92 years, there were 641 deaths (179 CRC-specific deaths). Patients in the highest quartile of the post-diagnostic 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 CRC-specific death and a 37% lower risk (HR=0.63, 95% CI: 0.50-0.78) of overall death 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 CRC-specific and overall mortality for the same comparison (CRC-specific: HR=0.50, 95% CI: 0.32-0.79; overall: HR=0.59, 95% CI: 0.47-0.75). The post-diagnostic diet score was not statistically significantly associated with either CRC-specific or overall mortality.
Greater adherence to the WCRF/AICR cancer prevention recommendations was associated with improved survival in CRC patients.
The study provided support for CRC patients to follow cancer prevention recommendations after diagnosis. Future studies on cancer survivors will continue to contribute to evidence-based diet and lifestyle recommendations for cancer patients.