Meat and heme iron intake and risk of squamous cell carcinoma of the upper aero-digestive tract in the European Prospective Investigation into Cancer and Nutrition (EPIC).

BACKGROUND: Evidence from prospective studies on intake of meat and fish and risk of squamous cell carcinoma (SCC) of the upper aero-digestive tract (UADT) is scarce. We prospectively investigated the association of meat and fish intake with risk of SCC of the UADT and the possible mechanism via heme iron in the large multicenter European Prospective Investigation into Cancer and Nutrition (EPIC) study. METHODS: Multivariable proportional hazards models were used to estimate relative risks (RR) of SCC of the UADT in relation to intake of total meat, as well as subtypes of meat, fish, and heme iron among 348,738 individuals from 7 European countries. RESULTS: During an average follow-up of 11.8 years, a total of 682 incident cases of UADT SCC were accrued. Intake of processed meat was positively associated with risk of SCC of the UADT in the total cohort [highest vs. lowest quintile: RR = 1.41; 95% confidence interval (CI) = 1.03-1.94], however, in stratified analyses, this association was confined to the group of current smokers (highest vs. lowest quintile: RR = 1.89; 95% CI = 1.22-2.93). Red meat, poultry, fish, and heme iron were not consistently related to UADT SCC. CONCLUSION: Higher intake of processed meat was positively associated with SCC of the UADT among smokers. Although this finding was stable in various sensitivity analyses, we cannot rule out residual confounding by smoking. Confirmation in future studies and identification of biologic mechanisms is warranted. IMPACT: Smokers may further increase their risk for SCC of the UADT if they additionally consume large amounts of processed meat.

Anthropometry and esophageal cancer risk in the European prospective investigation into cancer and nutrition.

BACKGROUND: Increasing evidence suggests that general obesity [measured by body mass index (BMI)] is positively associated with risk of esophageal adenocarcinoma (EAC). In contrast, previous studies have shown inverse relations with esophageal squamous cell carcinoma (ESCC). However, it is still unclear whether body fat distribution, particularly abdominal obesity, is associated with each type of esophageal cancer. METHODS: We applied multivariable adjusted Cox proportional hazards regression to investigate the association between anthropometric measures and risk of EAC and ESCC among 346,554 men and women participating in the European Prospective Investigation into Cancer and Nutrition. All statistical tests were two sided. RESULTS: During 8.9 years of follow-up, we documented 88 incident cases of EAC and 110 cases of ESCC. BMI, waist circumference, and waist-to-hip ratio (WHR) were positively associated with EAC risk [highest versus lowest quintile; relative risk (RR), 2.60; 95% confidence interval (95% CI), 1.23-5.51; P(trend) < 0.01; RR, 3.07; 95% CI, 1.35-6.98; P(trend) < 0.003; and RR, 2.12; 95% CI, 0.98-4.57; P(trend) < 0.004]. In contrast, BMI and waist circumference were inversely related to ESCC risk, whereas WHR showed no association with ESCC. In stratified analyses, BMI and waist circumference were significantly inversely related to ESCC only among smokers but not among nonsmokers. However, when controlled for BMI, we found positive associations for waist circumference and WHR with ESCC, and these associations were observed among smokers and nonsmokers. CONCLUSION: General and abdominal obesity were associated with higher EAC risk. Further, our study suggests that particularly an abdominal body fat distribution might also be a risk factor for ESCC.