Abstract
BackgroundWe examined differences in cancer incidence between women and men and the extent to which these persisted after accounting for established risk factors.MethodsProspective analyses in the UK Biobank to examine associations between sex and risk of 15 cancers (and 13 subtypes) using minimal and multivariable-adjusted Cox proportional hazards regression models. Multivariable models were stratified for age, deprivation index, and region, and adjusted for ethnicity, qualifications, height, BMI, smoking status, alcohol, and site-specific risk factors.ResultsDuring 10.5 (SD 2.2) years of follow-up, 32,315 incident cancers across 15 anatomical sites (58.1% in women) were identified in 470,771 individuals (53.8% women). Some differences in cancer risk between the sexes attenuated to the null in the multivariable-adjusted models, but men remained at greater risk than women for cancers at eight sites: oesophageal adenocarcinoma (hazard ratio 5.45; 95% confidence interval, 4.18-7.12), gastric cardia (3.65; 2.48-5.38), bladder (3.47; 2.85-4.24), oral cavity (2.06; 1.69-2.51), liver (1.91; 1.48-2.47), kidney (1.77; 1.51-2.09), rectum (1.70; 1.47-1.96), and leukaemia (1.43; 1.21-1.69). Men had lower risks for cancers of the breast, thyroid (0.36; 0.26-0.49), anus (0.41; 0.26-0.64), and lung adenocarcinoma (0.72; 0.62-0.84).ConclusionFurther research on these sex differences in risk may provide insights into cancer aetiology.