MRI Measures of Fat Distribution and Risk of Cancer

Background: Excess adiposity has been associated with an increased risk of several types of cancer. The relationship between fat tissue distribution in the body and these outcomes is less well known. Using data from the UK Biobank imaging substudy, we evaluated the prospective relationship between MRI-derived measurements of adipose tissue distribution and the risk of the major site-specific cancers associated with obesity. Methods: Between 2014 and 2023, MRI measurements on adipose tissue distribution and volume were obtained from 49,044 (52.2% women) cancer-free UK Biobank participants. Quantitative MRI data included volumes of visceral adipose tissue (VAT) and abdominal subcutaneous adipose tissue (ASAT), total abdominal fat/height squared (TAT/h²), and muscle fat infiltration (MFI). Cox proportional hazard models adjusted for cancer-specific risk factors were used to generate HRs and 95% confidence intervals. Results: Incident cancer cases of the breast (N ¼ 179), endometrium (n ¼ 30), colorectum (n ¼ 145), and kidney (n ¼ 50) were ascertained over a median follow-up of 4.5 years. In women, VAT, TAT/h², and MFI were positively associated with a risk of postmenopausal breast cancer, and ASAT was associated with an increased risk of endometrial cancer. In men, VAT and TAT/h² were positively associated with a risk of colorectal cancer, whereas ASAT was associated with an increased risk of kidney cancer. Conclusions: The present study showed that increasing volumes of VAT, ASAT, and MFI were associated with cancers at specific organ sites, indicating a potential role for adipose tissue distribution in influencing cancer risk. Impact: Both visceral and subcutaneous fat may have an impact on the risk of certain cancers.