Prospective analysis of associations of preclinical and clinical obesity with risk of 28 cancer types

Previous research has primarily relied on body mass index to assess adiposity in relation to cancer risk, despite its inability to capture fat distribution, body composition, and the metabolic activity of adipose tissue. Analysis of the prospective UK Biobank (459,342 participants enrolled between 2006 and 2010) found 47,060 incident cancers during 11.6 years of follow-up. Preclinical obesity (excess adiposity without organ dysfunction) was associated with 11 cancer types across multiple organ systems, whereas clinical obesity (with organ dysfunction) was associated with 12 cancer types. Conversely, preclinical and clinical obesity were inversely associated with non-fatal prostate cancer. The authors conclude that the link between preclinical obesity and increased cancer rik suggests that obesity-related carcinogenesis begins before clinically detectable abnormalities.