Patients with stage III colon cancer who consumed anti-inflammatory diets demonstrated significantly improved overall survival compared to those following pro-inflammatory dietary patterns, according to a Dana-Farber Cancer Institute analysis of a phase 3 clinical trial. The study found that patients consuming the most pro-inflammatory diets had an 87% higher risk of death than those with the least inflammatory dietary patterns.
Dr. Sara Char, clinical fellow in Hematology and Oncology at Dana-Farber Cancer Institute, presented the findings at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting. The research analyzed data from the CALGB/SWOG 80702 trial, which investigated adjuvant therapy duration and anti-inflammatory drug use in stage III colon cancer patients.
Study Design and Patient Population
The analysis included 1,625 patients from the original 2,526 enrolled in the CALGB/SWOG 80702 trial, initiated in 2010. All participants had resected stage III colon cancer and were treated with surgery followed by either 3 or 6 months of FOLFOX chemotherapy (leucovorin, fluorouracil, and oxaliplatin), with or without the COX-2 inhibitor celecoxib.
Researchers used validated food frequency questionnaires to calculate empirical dietary inflammatory pattern (EDIP) scores for each patient. These scores estimate the inflammatory potential of habitual diets, with patients stratified into quintiles based on their EDIP scores.
Dietary Patterns and Inflammatory Potential
A pro-inflammatory diet includes higher amounts of red meat, processed meats, refined grains, and sugar-sweetened beverages, while an anti-inflammatory diet frequently includes coffee, tea, and a variety of vegetables, including leafy greens. As Dr. Char explained, "A proinflammatory diet would be enriched with these proinflammatory food groups whereas a less inflammatory diet might be enriched with more of the anti-inflammatory food groups."
Survival Outcomes
The primary analysis focused on overall survival outcomes after following patients for multiple years. While EDIP scores were not significantly associated with disease-free survival, the study's primary endpoint, the analysis revealed a statistically significant association between higher EDIP scores and worse overall survival.
"Patients in the highest EDIP quintile—those who consumed the top 20% most inflammatory diets—had an 87% higher risk of death [compared with] those in the lowest quintile, who consumed the least inflammatory diets," Dr. Char reported. This finding remained consistent after adjusting for potential confounders in multivariable-adjusted models.
Combined Effect of Diet and Physical Activity
The study also assessed physical activity levels, defining high physical activity as the equivalent of regularly walking at a 2-3 mile per hour pace for one hour approximately three times a week or more. Patients who combined anti-inflammatory diets with higher levels of physical activity achieved the most favorable outcomes, with a 63% lower risk of death compared to patients who consumed the most pro-inflammatory diets and engaged in lower levels of physical activity.
Independence from Anti-Inflammatory Medications
Subgroup analyses evaluated whether concomitant use of anti-inflammatory agents, including aspirin and celecoxib, modified the association between dietary inflammation and overall survival. The observed association between higher EDIP scores and increased mortality remained consistent across these subgroups, indicating that the pro-inflammatory impact of diet on survival was independent of pharmacologic anti-inflammatory use.
The use of celecoxib did not have a significant influence on the relationship between diet and survival, suggesting that dietary interventions may provide benefits beyond those achieved through anti-inflammatory medications alone.
Clinical Context and Implications
Approximately 150,000 individuals are diagnosed with colorectal cancer each year in the United States, making it the third most diagnosed cancer globally and the second-leading cause of cancer-related death. The median 5-year survival for patients with stage III colon cancer is around 80%, though 25 to 35% of patients experience cancer recurrence during that time.
"One of the most common questions that patients ask is what they should do after treatment to maximally reduce their risk of cancer recurrence and improve survival. These findings add to the published literature about the importance of dietary patterns and physical activity in outcomes of patients with colorectal cancer," Dr. Char noted.
Dr. Kimmie Ng, associate chief of the Division of Gastrointestinal Oncology and co-senior author, emphasized the study's significance: "This study provides additional evidence that diet may be important for improving outcomes and survival in patients with stage III colon cancer. Further studies are needed to tailor specific dietary recommendations for patients with colon cancer, and to understand the biological mechanisms underlying the relationship between proinflammatory diets and survival."
The research builds on previous findings showing that systemic inflammation can increase the risk of colon cancer development and progression, and that anti-inflammatory medications can decrease cancer recurrence risk in selected stage III colon cancer patients. Dana-Farber researchers plan more detailed investigations of the biological effects of diet and lifestyle on colon cancer outcomes, including studies in patients with metastatic colon cancer and those diagnosed at younger ages, under 50.
