Abstract 6495: The relationship between inflammatory diet score and cancer-specific outcomes: Systematic review and meta-analysis
Authors: Han Eric , Lee Eunkyung , Li David , Garcia Jeanette , Castillo Humberto Lopez 
Published: April 2023

Abstract
Cancer remains one of the most prevalent diseases in the United States and a leading cause of death. Large prospective studies have found significant correlations between dietary intake and cancer. Chronic inflammation promotes pro-cancer inflammatory environments and nutrition can influence inflammation, with the intake of certain food items increasing inflammatory biomarkers. The objective of this research was to explore the relationship between inflammatory diet score measured by the Dietary Inflammatory index and all-cause mortality, cancer-specific mortality, and cancer recurrence among cancer survivors. Web of Science, Medline, CINHAL, and PsycINFO databases were searched to collect potentially eligible sources that focus on dietary inflammation and cancer outcomes. All sources were uploaded to Covidence software and screened by two independent blinded reviewers. The quality of the sources was assessed using the Newcastle Ottawa scale and relevant data was extracted and transferred to the Comprehensive Meta Analysis software and a random effects model was used to perform meta-analysis. Of the 1444 studies imported into the Covidence software, 13 passed all the screening stages and were included in the final analysis. Eight studies reported on pre-diagnosis diet while five others reported on post-diagnosis diet. Five studies reported on colorectal cancer, four on breast cancer, two on ovarian cancer, one on endometrial cancer and one on prostate cancer. Meta-analysis of the studies found that being in the highest postdiagnosis DII score indicating pro-inflammatory diet significantly increased the risk of all-cause death among cancer survivors by 33.5% (HR = 1.335, 95% CI = 1.049, 1.698, n = 6). Analysis did not show a statistically significant association between DII score and cancer mortality or recurrence (HR = 1.097, 95% CI = 0.939, 1.281, n = 6). Analysis by cancer subtype found a significant correlation between postdiagnosis DII score and all-cause mortality among the breast cancer survivors (HR = 1.335, 95% CI = 1.041, 1.711, n = 3) though there were no significant associations between DII and the outcomes of interest from the other cancer types. The meta-analysis concludes that being in the highest postdiagnosis DII score group significantly increased the risk of all-cause death among cancer survivors. This suggests that risk of all-cause mortality could be reduced for cancer survivors by consuming more anti-inflammatory food components and reducing consumption of pro-inflammatory foods. These findings also warrant more research in this field to clarify the relationship between dietary inflammation as measured by the DII and cancer outcomes, particularly cancer-specific mortality.
Citation Format: Eric Han, Eunkyung Lee, David Li, Jeanette Garcia, Humberto Lopez Castillo. The relationship between inflammatory diet score and cancer-specific outcomes: Systematic review and meta-analysis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6495.