Eating a less inflammatory diet may improve survival for patients with stage III colon cancer, according to results from a large prospective cohort study presented at the 2025 annual meeting of the American Society of Clinical Oncology.
“One of the most common questions that patients ask is what diet they should be following to maximally reduce their risk of cancer recurrence and improve survival. 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 investigator Sara Char, MD, an oncologist at Dana-Farber Cancer Institute, in Boston.
To assess the effects of diet on the risk for colon cancer recurrence, Dr. Char and her co-investigators conducted a prospective cohort study by analyzing the diet habits of a subset of patients enrolled in the phase 3 CALGB/SWOG 80702 clinical trial. In the trial, investigators tested three versus six months of adjuvant chemotherapy, with or without the anti-inflammatory medication celecoxib (Celebrex, Viatris).
Of the approximately 2,500 patients enrolled in CALGB/SWOG 80702, the investigators followed 1,625 patients as part of the prospective cohort study. All patients had stage III colon cancer that had been resected. The average age of the participants was 60.9 years. The patients reported their diet and exercise habits at six weeks after being randomly assigned to a treatment group and again 14 to 16 months after random assignment.
To score diets, the researchers used the empirical dietary inflammatory pattern (EDIP) tool, a weighted sum of 18 food groups: nine pro-inflammatory and nine anti-inflammatory. Examples of pro-inflammatory foods include red meat, processed meats, refined grains and sugary drinks. Examples of anti-inflammatory foods include coffee, tea, dark yellow vegetables and leafy green vegetables. A high EDIP score indicates a pro-inflammatory diet and a low EDIP score indicates a less inflammatory diet.
Baseline aspirin use, assigned chemotherapy (three vs. six months) and assigned pharmacotherapy (celecoxib vs. placebo) were not significantly different across EDIP quintiles.
Presenting the findings at the meeting (abstract LBA3509), Dr. Char reported that pro-inflammatory diets were associated with worse outcomes. Patients with the highest EDIP scores and very pro-inflammatory diets had an 87% higher risk for death than those who followed highly anti-inflammatory diets (hazard ratio [HR], 1.87; 95% CI, 1.26-2.77; P=0.01).
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%), have an ECOG Performance Status Scale 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%).
The researchers also found that exercise habits, another modifiable factor associated with systemic inflammation, affected overall survival. Patients who consumed less inflammatory diets and exercised more often (at least nine metabolic equivalent hours per week) had the best overall survival, with a 63% lower risk for death compared with those who followed pro-inflammatory diets and exercised less.
—Kate O’Rourke
Dr. Char reported a consulting/advisory role with Goodpath.
This article is from the October 2025 print issue.