Abstract 3493: Interactions between adiponectin pathway polymorphisms and obesity on breast cancer risk among African American postmenopausal women

Abstract

Abstract Purpose: A decreased circulating adiponectin concentration is associated with obesity and an increased breast cancer risk among postmenopausal women. Yet, the interplay between adiponectin-associated genetic variants, obesity, and breast cancer risk is unclear in African American (AA) postmenopausal women. We examined adiponectin pathway polymorphisms for their association with breast cancer risk among AA postmenopausal women. We also explored a gene-environment interaction between adiponectin pathway polymorphisms and obesity for the risk of breast cancer. Method: Using the Women's Health Initiative SNP Health Association Resource Study, we identified 37 single-nucleotide polymorphisms (SNPs) in relation to the adiponectin pathway. Body-fat distributions were determined using three independent indices including body mass index (BMI), waist-to-hip ratio (WHR), and waist circumference (WC). We used multiple Cox proportional hazards regression models to estimate hazard ratios and 95% confidence intervals (CIs) for the association with breast cancer. Obesity-stratified analysis and tests for the joint effects with the SNPs were conducted. Results: Of 7,991 AA postmenopausal women, 402 reported of having an invasive breast cancer with a mean follow-up of 14.5 years. The majority were obese, had low WHR (< 0.85), and had high WC (< 88 cm). Of 37 adiponectin pathway-related SNPs, 3 SNPs were significantly associated with breast cancer risk (KCNK9 rs2468677, OR8S1-LALBA rs11168618, and EIF4A2 rs266719). Among women who have under or normal bodyweight, the minor allele GG genotype of NMU rs13434995 had an elevated risk of postmenopausal breast cancer compared to those with the major allele AA genotype. Women who carry the heterozygous TC genotype of OR8S1-LALBA rs11168618 and are obese jointly increased the risk of breast cancer (relative excess risk due to interaction = 0.58, 95% CI = 0.35, 0.80). Conclusion: Our findings revealed the association between the previously confirmed adiponectin pathway-related SNPs and breast cancer risk among AA postmenopausal women. We also demonstrated that obesity plays an important role as an effect modifier in the relationship between the SNPs and breast cancer, suggesting 1) the potential use of metabolic and genetic biomarkers for identifying a greater risk for breast cancer and 2) support for the research to promote interventions to those with risk genotypes, thus reducing breast cancer risk. Citation Format: Gina E. Nam, Zuo-Feng Zhang, Jianyu Rao, Hua Zhou, Su Yon Jung. Interactions between adiponectin pathway polymorphisms and obesity on breast cancer risk among African American postmenopausal women [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3493.