To the Editor We read with great interest the article by Lazzati and colleagues¹ on investigating whether bariatric surgery may be associated with the incidence of gastroesophageal cancer in patients with obesity. By testing a nationwide cohort of patients with obesity, this study illustrated that bariatric surgery could significantly reduce the incidence of esophagogastric cancer and overall in-hospital mortality. However, 2 points of the study warrant discussion.

In this study, esophagogastroduodenal endoscopy and Helicobacter pylori infection eradication are routine workups for bariatric surgery candidates.² Nevertheless, it is certainly a confounding factor because of missing the 2 assessments in the control group cohort. To account for differential bias by endoscopy (misdiagnosis of cancer in the control group), Lazzati et al¹ excluded cancer events occurring during the first 2 years. However, confounder adjustment for the detection bias caused by H pylori eradication, one of the most viable strategies for gastrointestinal cancer prevention,³ was not mentioned. We suppose this preoperative intervention may delay the occurrence of gastroesophageal cancer and contribute to decreased risk of gastroesophageal malignant neoplasms. Thus, data from this study should be interpreted with caution.