Sara Char, MD, Dana-Farber Cancer Institute, Boston, Massachusetts, discusses results from the CALGB/SWOG 80702 trial which assessed the impact a proinflammatory diet has on survival in patients with stage 3 colon cancer. 

Study findings showed that a proinflammatory diet was associated with worse overall survival (OS) in this patient population. 

Dr Char presented these results at the 2025 ASCO Annual Meeting in Chicago, Illinois. 

Transcript: 

My name is Sara Char, I am a clinical oncology fellow at the Dana-Farber Cancer Institute, and I'm excited to talk a little bit about our study today which was examining the association between empirical dietary inflammatory pattern or EDIP and survival in patients with stage 3 colon cancer. 

Some background for why we did this study, we know that systemic inflammation is implicated in both colon cancer development and in its progression and prior studies have shown that elevated levels of inflammatory markers in the blood, CRPIL-6 and TNFα2, have been associated with worse outcomes in patients with stage 3 colon cancer so we wanted to know whether intake of a proinflammatory diet would affect survival outcomes in patients with stage 3 colon cancer. 

To answer this question, we used a validated tool for examining the inflammatory potential of diets called the empirical dietary inflammatory potential or EDIP. EDIP is a weighted sum of 18 food groups, it's 9 proinflammatory food groups and 9 anti-inflammatory food groups [and] when taken together you get an EDIP score where a higher score corresponds with the intake of a more proinflammatory diet and some examples of the proinflammatory foods are things like red meat, processed meats, refined grains and examples of the anti-inflammatory foods include leafy green vegetables, dark yellow vegetables, coffee, and tea. Using patient reported dietary data, we can create an EDIP score that gives us a sense of how inflammatory that person's diet is. 

Our study was designed as a prospective cohort study and a secondary analysis of a phase 3 clinical trial called CALGB/SWOG 80702. For background, the initial phase 3 clinical trial was designed to randomize patients with resected stage 3 colon cancer to receive either 3 versus 6 months of adjuvant FOLFOX chemotherapy and additionally randomize them to receive celecoxib, which is an anti-inflammatory medication, versus placebo daily for 3 years. In this clinical trial, whose results have been reported, there was no significant difference in disease-free survival or overall survival by celecoxib use and so that allowed us to pool the participants in this study for a secondary analysis. The participants in the study additionally had consented, some of them had consented, to participate in a diet and lifestyle companion study and in this study they filled out questionnaires about their diet and lifestyle habits at 2 time points. Part of this diet and lifestyle questionnaire included a food frequency questionnaire using a validated measure that asked participants about 131 food groups that they consumed over the prior 3 months. We used a Cox proportional hazards model to look at the association between empirical dietary inflammatory pattern and a primary outcome of disease-free survival and a secondary outcome of overall survival. 

In our study, when looking at our primary outcome of disease-free survival, we did not find a statistically significant difference in disease-free survival by intake of a proinflammatory diet and this was in our multi-variable adjusted model however, when we looked at overall survival, there was a significant difference in overall survival. When we compared those who had intake of the most proinflammatory diets, or the highest EDIP quintile, compared to those who had intake of the least inflammatory diets, or the lowest EDIP quintile, the hazard ratio for overall survival was 1.87 in our multivariable adjusted model and that was statistically significant. We looked at the association between EDIP and overall survival across different subgroups and notably the use of aspirin and the use of celecoxib, which are anti-inflammatory medications, did not impact this association. 

Finally, we were interested in modeling the joint effect of physical activity and diet on overall survival as both physical activity and EDIP are correlated with systemic inflammation. We divided our patients into 2 physical activity groups, lower and higher levels of physical activity, using a cutoff of 9 met hours per week, which roughly corresponds to 30 minutes of vigorous walking 5 days a week plus some light yoga. We found that the best survival outcomes were achieved in those who had higher levels of physical activity and consumed less inflammatory diets compared to those who had lower levels of physical activity and consumed the most inflammatory diets and the hazard ratio for that association was 0.37, which was statistically significant. 

Overall, our study findings showed that greater intake of a proinflammatory diet was associated with worse overall survival, but not disease-free survival in patients with stage 3 colon cancer and this association was not affected by aspirin use or celecoxib, and we saw the best survival outcomes in those who had higher levels of physical activity and consumed less inflammatory diets. Our study adds to the existing literature that diet may impact survival in stage 3 colon cancer and we're going to need further studies to be able to tailor these findings into dietary recommendations for patients.

Source: 

Char S, Shi Q, Zemla T, et al. Association between empirical dietary inflammatory pattern (EDIP) and survival in patients with stage III colon cancer: Findings from CALGB/SWOG 80702 (Alliance). Presented at 2025 ASCO Annual Meeting. May 30-June 3, 2025; Chicago, IL. Abstract LBA3509