Height and cancer risk in East Asians: Evidence from a prospective cohort study and Mendelian randomization analyses

Background Height is associated with increased cancer risk, but most studies focus on Western populations. We aimed to evaluate this relationship in East Asians. Method Observational analyses were performed utilizing data from China Kadoorie Biobank (CKB) prospective cohort. Adjusted hazard ratios (HRs) and corresponding 95 % confidence intervals (CIs) were estimated using Cox proportional hazards models. Two-sample Mendelian randomization (MR) analyses explored causal effects between height and cancer using data from Korean Genome and Epidemiology Study (KoGES), Biobank Japan (BBJ), and CKB. Results Over a median 10.1-years follow-up, 22,731 incident cancers occurred. In observational analyses, after Bonferroni correction, each 10 cm increase in height was significantly associated with higher risk of overall cancer (HR 1.16, 95 % CI 1.14-1.19, P < 0.001), lung cancer (1.18, 95 % CI 1.12-1.24, P < 0.001), esophageal cancer (1.21, 95 % CI 1.12-1.30, P < 0.001), breast cancer (1.41, 95 % CI 1.31-1.53, P < 0.001), and cervix uteri cancer (1.29, 95 % CI 1.15-1.45, P < 0.001). Each 10 cm increase in height was suggestively associated with increased risk for lymphoma (1.18, 95 % CI 1.04-1.34, P = 0.010), colorectal cancer (1.09, 95 % CI 1.02-1.16, P = 0.010), and stomach cancer (1.07, 95 % CI 1.00-1.14, P = 0.044). In MR analyses, genetically predicted height (per 1 standard deviation increase, 8.07 cm) was suggestively associated with higher risk of lung cancer (odds ratio [OR] 1.17, 95 % confidence interval [CI] 1.02-1.35, P = 0.0244) and gastric cancer (OR 1.14, 95 % CI 1.02-1.29, P = 0.0233). Conclusions Taller height was significantly related to a higher risk for overall cancer, lung cancer, esophageal cancer, breast cancer, and cervix uteri cancer. Our findings suggest that height may be a potential causal risk factor for lung and gastric cancers among East Asians.