Circulating hormones and risk of gastric cancer by subsite in three cohort studies

Background Obesity has been positively associated with gastric cancer. Excess fat impacts hormones, which have been implicated in carcinogenesis. We investigated obesity-related hormones and cardia gastric cancer (CGC) and non-cardia gastric cancer (NCGC) risk. Methods Nested case–control studies were conducted within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort (61 CGCs, and 172 NCGCs and matched controls) and the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) study (100 CGCs and 65 NCGCs and matched controls); serum hormones were measured. In UK-Biobank ( n = 458,713), we included 137 CGCs and 92 NCGCs. Sex-specific analyses were conducted. For EPIC and ATBC, odds ratios (ORs), and for UK-Biobank hazard ratios (HRs), were estimated using conditional logistic regression and Cox regression, respectively. Results Insulin-like growth-factor-1 was positively associated with CGC and NCGC in EPIC men (OR per 1-SD increase 1.94, 95% CI 1.03–3.63; OR per 1-SD increase 1.63, 95% CI 1.05–2.53, respectively), with similar findings for CGC in UK-Biobank women (HR per 1-SD increase 1.76, 95% CI 1.08–2.88). Leptin in EPIC men and C-peptide in EPIC women were positively associated with NCGC (OR T3 vs. T1 2.72, 95% CI 1.01–7.34 and OR per 1-SD increase 2.17, 95% CI 1.19–3.97, respectively). Sex hormone-binding globulin was positively associated with CGC in UK-Biobank men (HR per 1-SD increase 1.29, 95% CI 1.02–1.64). Conversely, ghrelin was inversely associated with NCGC among EPIC and ATBC men (OR per 1-SD increase 0.53, 95% CI 0.34–0.84; OR per 1-SD increase 0.22, 95% CI 0.10–0.50, respectively). In addition, dehydroepiandrosterone was inversely associated with CGC in EPIC and ATBC men combined. Conclusions Some obesity-related hormones influence CGC and NCGC risk.