Abstract 3338: Understanding the effect of racial disparities on patients response to dietary intervention during cancer therapy
Authors: Jusu Sylvester , Dykes Kaitlyn , Ko Kevin , DeAngelis Tiziana , Mitchell Edith , Simone Nicole 
Published: August 2019

Purpose:

African American (AA) women have a lower incidence of breast cancer however, their mortality rate is significantly higher compared to Caucasian (C) women. It is postulated that this is in part, due to the increased prevalence of chronic metabolic syndromes such as obesity and diabetes in the AA population. Also, cytotoxic therapies such as radiation, have decreased efficacy in obese and diabetic patients compared to normal weight counterparts. In this study we investigated whether caloric restriction (CR) during radiation, could affect metabolic differences to affect this disparity. We hypothesize that CR may better benefit AA patients via modulation of inflammatory pathway to improve cancer outcomes.

Methods:

Thirty five patients (16 AA/16C) with Stage 0 or 1 breast cancer were accrued from 2013-2016 and enrolled on an IRB approved study (NCT01819233). Baseline caloric intake was assessed by food diaries for 7-10 days prior to RT simulation and patients were counseled to decrease their total caloric intake by 25% starting after RT simulation. Patients underwent CR for 10 consecutive weeks: 2 weeks of CR alone, 6 weeks of CR and RT to a dose of 60Gy, and 2 weeks of CR alone after RT. Patients were evaluated before and after the 10 weeks for biometric properties, quality of life metrics and serum markers.

Results:

Compliance with diet between AA and C and cohorts was comparable and while the total cohort lost an average of 9.21 ± 1.27 lbs, the C cohort had a greater decrease in weight of 11.67 ±2.56 lbs compared to the AA patients who lost an average of 7.33 ±1.62 lbs. To determine if the AA patients had a molecular benefit to diet, oncomiR-21, a regulator of inflammation was evaluated. miR-21 increased by 200 fold in control patients treated with RT without diet. The C patients on CR had a dampened upregulation with a miR-21 that only increased 3.2 ± 0.02 fold, while the AA patients had a significant change with an upregulation of 1.9 ± 0.55, p&lt;0.001. A 200 analyte protein array analysis showed AA patients had a unique protein profile with 15.42 % down-regulated analytes compared to 10.45 %. AA patients showed significant reduction in pro-inflammatory markers including IL-1, IL-6, EGFR, bNGF, FGF-4, TGF-b and BMP 5 and BMP-7 (p&lt;0.05).

Conclusions:

Though AA patients experienced less weight loss compared to their C counterparts, the molecular benefit experienced was significant in terms of the decreased inflammatory response, skin toxicity and decrease in migration/invasion pathways. Further investigation using diet to narrow the breast cancer outcome disparity experienced by our AA patients is warranted.

Note: This abstract was not presented at the meeting.

Citation Format: Sylvester Jusu, Kaitlyn Dykes, Kevin Ko, Tiziana DeAngelis, Edith Mitchell, Nicole Simone. Understanding the effect of racial disparities on patients response to dietary intervention during cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3338.