Results from a large, prospective study show that eating a less inflammatory diet may reduce the risk of death for patients with stage III colon cancer. The research is being presented at the 2025 ASCO Annual Meeting (Abstract LBA3509).
Chronic systemic inflammation is a known risk factor for the development of colon cancer, as well as disease progression. It can be caused by certain chronic conditions, such as diabetes and inflammatory bowel disease, as well as dietary, lifestyle, and environmental factors.
One recent study found that higher systemic inflammation after diagnosis was associated with worse survival among patients with stage III colon cancer. Anti-inflammatory medications like aspirin have also been shown to reduce both the risk of developing colorectal cancer, as well as cancer recurrence in certain subsets of patients.
“While there have been many studies examining dietary factors and the risk of developing colorectal cancer, there is significantly less known about how diet impacts colon cancer outcomes after diagnosis. This study sheds light on the relationship between dietary patterns and survival in patients with stage III colon cancer,” said lead study author Sara K. Char, MD, of Dana-Farber Cancer Institute in Boston.
Study Details
This prospective cohort study analyzed the dietary habits of a subset of patients enrolled in the phase III CALGB/SWOG 80702 clinical trial in order to assess the effects of diet on the risk of colon cancer recurrence. The CALGB/SWOG 80702 trial compared 3 vs 6 months of adjuvant chemotherapy, with or without the anti-inflammatory medication celecoxib.
Of the approximately 2,500 patients enrolled in CALGB/SWOG 80702, there were 1,625 patients followed as part of this study. The patients all had resected stage III colon cancer. The average age of the participants was 60.9 years. The patients reported their diet and exercise habits at 6 weeks after being randomly assigned to a treatment group in the CALGB/SWOG 80702 study and again 14 to 16 months after random assignment.
Patients’ diets were scored using the empirical dietary inflammatory pattern (EDIP) tool, which is a weighted sum of 18 food groups: 9 pro-inflammatory (eg, red meat, processed meats, refined grains, and sugary drinks) and 9 anti-inflammatory (eg, coffee, tea, dark yellow vegetables, and leafy green vegetables). A high EDIP score indicates a pro-inflammatory diet, and a low EDIP score represents a less inflammatory diet.
Key Findings
The study found that patients who consumed the most pro-inflammatory diets and had the highest EDIP scores were more likely to be younger (average age, 58.7 vs 61.3 years), more likely to be female (64% vs 48.9%), more likely to have an ECOG score of 1 or 2 (35.7% vs 19.4%), less likely to be White (76.6% vs 92.0%), and more likely to be Black (15.4% vs 3.7%).
Pro-inflammatory diets were associated with worse outcomes. Patients with the highest EDIP scores and very pro-inflammatory diets had an 87% higher risk of death than those who ate highly anti-inflammatory diets.
Exercise habits, another modifiable risk factor associated with systemic inflammation, also impacted overall survival. Patients who consumed less inflammatory diets and exercised more often had the best overall survival, with a 63% lower risk of death compared with patients who ate pro-inflammatory diets and exercised less.
There was no significant difference in disease-free survival between the patients who ate a pro-inflammatory diet and those who ate an anti-inflammatory diet. In addition, low-dose aspirin use and treatment regimen on the CALGB/SWOG 80702 trial were not significantly different between the groups.
Conclusion
“Our finding suggest that greater intake of a pro-inflammatory dietary pattern is associated with worse overall survival in patients with stage III colon cancer,” wrote the study authors. “Regular physical activity may attenuate the association, and further investigation of diet and physical activity intervention is warranted.”
Commenting on the study, Julie R. Gralow, MD, FACP, FASCO, ASCO Chief Medical Officer and Executive Vice President, noted: “This early but promising observational study suggests a powerful synergy: patients with stage III colon cancer who embraced anti-inflammatory foods and exercised regularly showed the best overall survival compared to those with inflammatory diets and limited exercise.”
Disclosure: The study was funded by the National Institutes of Health, Pfizer, and the Project P Fund. For full disclosures of the study authors, visit coi.asco.org.
