Background: Multiple myeloma (MM) takes a disproportionate toll on Black Americans compared to non-Hispanic whites, yet factors related to these disparities remain poorly understood. In a prior analysis of two prospective cohort studies examining diet and MM, a dietary inflammatory pattern was significantly associated with MM risk. Here, we investigate the association between dietary inflammatory index (DII) score and MM incidence in a cohort of US Black women. Methods: The Black Women’s Health Study (BWHS) is a prospective cohort study that enrolled 59,000 US self-identified Black women age 21-69 at entry in 1995. Incident cases of MM, identified among BWHS participants followed by biennial questionnaires, were confirmed via medical record review or linkage with cancer registries. We analyzed food frequency questionnaire (FFQ) data collected in 1995, excluding participants with implausible or missing FFQ data. We also excluded women diagnosed with cancer (other than non-melanoma skin cancer) prior to baseline. FFQ data were used to create a dietary inflammatory index (DII) for each person. The DII score includes total fat and cholesterol as pro-inflammatory dietary contributors, and n-3 PUFAs, selenium, and vitamin D as anti-inflammatory contributors. The DII has been previously associated with six inflammatory markers (CRP, IL-1b, IL-4, IL-6, IL-10, TNF-a). We evaluated associations of DII score quintile with MM incidence using Cox proportional hazards regression, adjusted for age, body mass index (BMI), and total energy intake (kcal/day). Results: Among 55,276 BWHS participants eligible for this analysis, we confirmed 313 incident cases of MM over 26 years of follow-up. Median age at baseline was 38 years old and median BMI was 26.6 kg/m2. The multivariable hazard ratio for women in the top quintile of DII (most pro-inflammatory diet) relative to the lowest quintile (most anti-inflammatory diet) was 0.71 (95% confidence interval: 0.43, 1.16). Conclusions: Overall, DII score was not associated with MM incidence in this cohort of US Black women. Ongoing analyses of markers of dietary inflammation and specific food groups may clarify the possible role of dietary components in MM pathogenesis. Cumulative time-varying models of DII score may also offer more robust conclusions in future analyses. 

Citation Format: Anisha V. Patel, Julie R. Palmer, Jessica L. Petrick, Kimberly A. Bertrand. Inflammatory dietary pattern and risk of multiple myeloma in US Black women [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B056.