Diet, dietary patterns and colorectal adenoma

Background: Colorectal cancer (CRC) is the 3rd most common cancer in the UK. It is estimated that 95% of CRC develop from sporadic colorectal adenoma. Colorectal adenoma is usually detected and removed during cancer screening but recurrence is common. According to the World Cancer Research Fund/American Institute of Cancer Research (WCRF/AICR), around 45% of CRC cases could be prevented by adopting a healthy lifestyle. The aim of this project was “To describe the dietary characteristics of patients newly diagnosed with high-risk colorectal adenoma and to explore the association between diet, dietary patterns and colorectal adenoma profile and the risk of recurrence”. Methodology: This is a secondary data analysis research project used data collected from colorectal adenoma patients recruited to the seAFOod trial, through the Bowel Cancer Screening Programme (BCSP) and data from the FACT study. Both used EPIC food frequency questionnaires (EPIC-FFQ) to assess diet and FETA dietary analysis software was used to extract the mean daily intake of foods and nutrients. Two approaches of dietary pattern analysis were used for the seAFOod trial data data-driven dietary patterns and the predefined pattern, the Dietary Inflammatory Index (DII). For the FACT study data, DII was calculated and adherence score to the cancer prevention recommendation of WCRF/AICR was assessed. SPSS software was used to perform calculations and statistical tests. Findings: For the seAFOod trial, the mean age of the population was 65 years, over 80% were overweight or obese. Analysis of dietary data for 674 patients showed that at baseline, diet was high in alcohol, red and processed meat and iron, and was low in fibre and vitamin D. Three dietary patterns were generated (High-energy pattern, the Healthy pattern and Alcohol and nuts pattern) and 76.7% of the patients had a proinflammatory DII score. During the 12 months after diagnosis, only males significantly reduced their intake of energy, red and processed meat. No association was found between dietary behaviour at baseline and the risk of colorectal adenoma in the 156 patients allocated to the placebo arm. No association between diet and colorectal adenoma profile at baseline or exit. For the FACT study analysis, 79.5% of the participants did not adhere to the WCRF/AICR cancer prevention recommendations and no association was found between adherence to these recommendations and markers of cell crypt proliferation, endocrine cells or keratin in colon biopsies. Conclusions: In this sample recruited through the BCSP, diet at baseline did not meet the recommendation for healthy diet provided by the WCRF/AICR and Public Health England recommendations, however, this analysis found no association between dietary behaviour at baseline and the risk of colorectal adenoma recurrence after 12 months. There was no association between adherence to the WCRF/AICR cancer prevention recommendations and the assessed cellular biomarkers.