Association between fat‐infiltrated axillary lymph nodes on screening mammography and cardiometabolic disease

Abstract

Objective: Ectopic fat deposition within and around organs is a stronger predictor of cardiometabolic disease status than body mass index (BMI). Fat deposition within the lymphatic system is poorly understood. This study examined the association between the prevalence of cardiometabolic disease and ectopic fat deposition within axillary lymph nodes (LNs) visualized on screening mammograms. Methods:A cross-sectional study was conducted on 834 women presenting for fullfield digital screening mammography. The status of fat-infiltrated LNs was assessed based on the size and morphology of axillary LNs from screening mammograms. The prevalence of cardiometabolic disease was retrieved from the electronic medical records, including type 2 diabetes mellitus (T2DM), hypertension, dyslipidemia, high blood glucose, cardiovascular disease, stroke, and non-alcoholic fatty liver disease.Results: Fat-infiltrated axillary LNs were associated with a high prevalence of T2DM among all women (adjusted odds ratio: 3.92, 95% CI: [2.40, 6.60], p-value < 0.001) and in subgroups of women with and without obesity. Utilizing the status of fatty LNs improved the classification of T2DM status in addition to age and BMI (1.4% improvement in the area under the receiver operating characteristic curve). Conclusion: Fat-infiltrated axillary LNs visualized on screening mammograms were associated with the prevalence of T2DM. If further validated, fat-infiltrated axillary LNs may represent a novel imaging biomarker of T2DM in women undergoing screening mammography.

Automated Classification of Fat-infiltrated Axillary Lymph Nodes on Screening Mammograms

“…A recent case□control study of 431 obese breast cancer patients further showed that patients with enlarged fat-infiltrated contralateral axillary LNs on breast MRI and mammography had a higher risk of ipsilateral breast cancer nodal metastases, independent of patients’ age, BMI, and tumor characteristics 9 . Another recent study reported a positive association between fat-infiltrated axillary LNs and the prevalence of type 2 diabetes (T2DM) in women with obesity, independent of age and BMI, and confirmed that fat-infiltrated LNs are more commonly seen in women with obesity 10 . A smaller study recently reported a decrease in serum lipids in obese women who had a reduction in the size of fatty nodes after bariatric surgery, raising the possibility that fatty LNs are a modifiable risk factor for cardiometabolic disease among people with obesity 12 .…”

“…The internal dataset used for this study included 886 full-field digital screening mammogram (FFDM) mediolateral oblique (MLO) views with detectable axillary LNs collected through a retrospective review of screening mammograms over an 8-month period at a tertiary care academic medical facility. The detailed data collection process is described in a previous study 10 . In brief, the largest visible axillary LN on the left or right MLO view was measured and labeled, with a final assessment achieved via a consensus review between two radiology reviewers 9 .…”

“…In contrast, ectopic fat deposition within and around organs such as the visceral cavity, liver, and muscle is a better predictor of obesity-associated illness and can be quantified from medical imaging such as MRI and CT 4,7,8 . Ongoing work suggests that axillary lymph nodes (LNs) are novel ectopic fatty depots associated with obesity-related disease 9,10 . However, annotated data in this domain are limited, and further large-scale studies are limited by the lack of an automated tool to annotate and characterize fat-infiltrated LNs.…”