Abstract PO-176: Obesity, breast cancer treatment, and systemic inflammation: A cross- sectional analysis of Hispanic and non-Hispanic white breast cancer survivors from New Mexico

Abstract

Abstract Background: Circulating markers of systemic inflammation have been found to be important long-term prognostic factors for breast cancer (BC). Studies have shown that obesity measured by percent body fat is the most significant predictor of inflammation in BC survivors. Specific BC treatments may also stimulate both local and systemic increases in inflammation. Little is known about the impact of other body size measures and BC treatment effects on inflammation among Hispanic BC survivors, an at-risk population due to their high prevalence of obesity and poor prognosis. Objective: We examined the associations between body size measures, BC treatment, and odds of systemic inflammation measured by soluble tumor necrosis factor receptor-II (sTNF-R2), a circulating pro-inflammatory biomarker, among Hispanic and non-Hispanic white (NHW) women diagnosed with breast cancer (stages I-IIIa) from the New Mexico Health, Eating, Activity, and Lifestyle cohort. Methods: A total of 397 BC survivors (96 Hispanic, 301 NHW) contributed data for the present study. Women with BC diagnosed between July 1996 and March 1999 were ascertained through the National Cancer Institute’s Surveillance Epidemiology and End Results registry in New Mexico. Baseline demographic characteristics, anthropometric measures, and blood samples were collected approximately 5 months post diagnosis by trained interviewers. Plasma levels of sTNF-R2 were assayed and measures were log-transformed to conform to normality. The study outcome of low vs high sTNF-R2 levels was based on the median value. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariable logistic regression models and were stratified by ethnicity. Results: There were higher proportions of women with high compared to low sTNF-R2 levels and the following obesity measures: high percent body fat (≥35%), high body mass index (BMI) (≥30 kg/m2), and high waist-hip ratio (>0.85). No significant differences were observed by sTNF-R2 levels and ethnicity or treatment. In multivariable models, we observed significant positive associations among women with high body fat percentage (compared to < 35%) (OR= 1.62, 95% CI 1.01-2.60) and morbid obesity (BMI ≥35 kg/m2 compared to BMI< 35 kg/m2) (OR= 4.16, 95% CI 1.43-12.10). High waist-hip ratio was not significantly associated with sTNF-R2. While current tamoxifen use was not associated with sTNF-R2, we did find that women who received radiation and chemotherapy were 2 times more likely to have high sTNF-R2 levels compared to women who did not have chemotherapy and radiation (OR= 2.04, 95% CI 1.03-4.01). Our results were not significantly modified by ethnicity. Conclusion: BC survivors with high body fat percentage and extreme BMI have increased odds of systemic inflammation measured by sTNF-R2. Survivors treated with chemotherapy and radiation are also more likely to experience systemic inflammation. Future studies will examine the long-term effects of these associations on poor prognosis. Citation Format: Avonne E. Connor, Kala Visvanathan, Stephanie D. Boone, Kathy B. Baumgartner, Richard N. Baumgartner. Obesity, breast cancer treatment, and systemic inflammation: A cross- sectional analysis of Hispanic and non-Hispanic white breast cancer survivors from New Mexico [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-176.