The Male Predominance in Esophageal Adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has increased rapidly during the past 4 decades in many Western populations, including North America and Europe. The established etiological factors for EAC include gastroesophageal reflux and obesity, Helicobacter pylori infection, tobacco smoking, and consumption of fruit and vegetables. There is a marked male predominance of EAC with a male-to-female ratio in incidence of up to 9:1. This review evaluates the available literature on the reasons for the male predominance, particularly an update on epidemiologic evidence from human studies during the past decade. The striking sex difference does not seem to be explained by established risk factors, given that the prevalence of the etiological factors and the strengths of associations between these factors and EAC risk are similar between the sexes. Sex hormonal factors may play a role in the development of EAC; estrogenic exposures may prevent such development, whereas androgens might increase the risk of EAC. However, continuing research efforts are still needed to fully understand the reasons for the male predominance of EAC.