Diet and physical activity advice for colorectal cancer survivors: critical synthesis of public-facing guidance.

PURPOSE: Colorectal cancer (CRC) survivors report that diet and physical activity guidance from healthcare professionals following discharge from care is limited. Survivors seek advice from alternative sources. This study critically synthesised the English language diet and physical activity guidance available online for CRC survivors. METHODS: We conducted an internet search to identify national cancer organisations (NCO) in countries with high CRC incidence rates. We searched NCO website content for guidance related to diet and physical activity. Recommendations were categorised by cancer phase (prevention/survivorship), cancer type, and the intended outcome (health or cancer-control-CRC recurrence/CRC-specific mortality). A synthesised guideline was derived from recommendations consistently made by at least half of the sources. RESULTS: We identified 12 NCOs from six countries, by whom 27 diet and physical activity recommendations were made. For CRC prevention, over 80% of recommendations were aimed at improving cancer-control outcomes. For CRC survivorship, less than 40% of recommendations were aimed at improving cancer-control outcomes. Physical activity was the only recommendation present on more than 50% of NCO websites aimed at improving cancer-control outcomes for CRC survivorship. CONCLUSION: Diet and physical activity guidance for CRC survivors on NCO websites is limited and primarily based on recommendations for improving general health, not improving cancer-control outcomes. NCO websites frequently refer survivors to primary prevention guidance, potentially reflecting the lack of evidence specific to CRC survivorship. There is a need for diet and physical activity advice for survivors that is evidence-based, comprehensive, and consistent across organisations and tailored to specific cancer sites.

Still too little evidence: the role of diet in colorectal cancer survivorship - a systematic review.

Colorectal cancer incidence (CRC) is influenced by dietary factors, yet the impact of diet on CRC-specific mortality and recurrence-free survival (RFS) remains unclear. This review provides a narrative summary of existing research on dietary factors affecting CRC-specific mortality, RFS, and disease-free survival (DFS). This study searched electronic databases to identify cross-sectional/prospective research investigating dietary intake on CRC-specific mortality, RFS, or DFS. Twenty-eight studies were included in the corpus. Because of high study heterogeneity, we performed a narrative synthesis of studies. Limited, but suggestive evidence indicates beneficial effects of adhering to the American Cancer Society (ACS) guidelines and a plant rich low-carbohydrate diet on risk of CRC-specific mortality, potentially driven by fiber from cereals, vegetables, and wholegrains, but not fruit. For RFS and DFS, a Western dietary pattern, high intake of refined grains, and sugar sweetened beverages correlated with increased risk of CRC recurrence and development of disease/death. Conversely, greater adherence to the ACS dietary and alcohol guidelines, higher ω-3 polyunsaturated fatty acids, and dark fish consumption reduced risk. Our findings underscore the need for (i) standardized investigations into diet's role in CRC survivorship, including endpoints, and (ii) comprehensive analyses to isolate specific effects within correlated lifestyle components.