Consumption of red and processed meat and risk for esophageal squamous cell carcinoma based on a meta-analysis

To provide a quantitative assessment of the association between red and processed meat intake and the risk of esophageal squamous cell carcinoma (ESCC), we summarized the evidence from observational studies.Relevant studies were identified in MEDLINE and EMBASE until October 31, 2012. Summary relative risks with 95% confidence intervals (CIs) were pooled with high versus low and linear dose-response random-effects models.A total of 21 studies (19 case-control and two cohort studies) with 6499 ESCC cases were included in this meta-analysis. Based on high versus low analysis, the summary relative risks of ESCC were 1.57 (95% CI, 1.26-1.95; Pheterogeneity = .003, I(2) = 56.0%) for red meat intake and 1.55 (95% CI, 1.22-1.97; Pheterogeneity = .029, I(2) = 45.3%) for processed meat intake. Subgrouped and sensitivity analyses revealed that the increment of ESCC risk with intakes of red meat and processed meat was stable and robust. These results are consistent with the results of the dose-response analyses. There was evidence of a nonlinear association of processed meat intake and ESCC risk (Pnonlinearity = .019).Intake of red and processed meat may be associated with significantly increased risk of ESCC. Further investigations with prospective designs are warranted.