Abstract
A large retrospective study of patients who are severely obese in France suggests that bariatric surgery may reduce the risk of gastric and esophageal cancers, alleviating concerns that surgery may increase such risk. Studies with longer follow-up and more histologic data are needed to better understand the connection between surgical procedures and subtypes of these cancers.
Bariatric surgery may reduce the risk of esophageal and gastric cancers in patients who are morbidly obese, according to a recent retrospective study. The findings help alleviate concern over whether weight-loss procedures contribute to Barrett esophagus, a common precursor of esophageal cancer.
Using a French database, investigators compared how 303,709 patients who are severely obese fared following bariatric surgery with a control group of 605,140 patients who did not have surgery (JAMA Surg 2023 Jan 11 [Epub ahead of print]). After an average follow-up period of almost 6 years, 337 patients developed esophageal and gastric cancers—83 in the surgery group versus 254 in the control group. The incidence rates were 4.9 and 6.9 per 100,000 people per year, respectively.
Although bariatric surgery often leads to sustained weight loss and improvements in obesity-related comorbidities and life expectancy, it may increase risk for certain cancers, the authors noted. Specifically, sleeve gastrectomy—one of the most performed procedures—is associated with gastroesophageal reflux disease, which can progress to Barrett esophagus. The condition develops in about 10% of patients after the surgery compared with 1% to 2% in the general population.
“This study provides important reassurance that the risk of esophageal or gastric cancer is not higher among those who undergo bariatric surgery, at least in the short- or medium-term,” says Farhad Islami, MD, PhD, senior scientific director of cancer disparity research at the American Cancer Society, who was not involved in the study. “However, longer follow-up is needed because these types of cancers typically take years to develop.”
In addition, the study's lack of data on histology and risk factors for subtypes of esophageal cancer—adenocarcinoma and squamous cell carcinoma—makes it difficult to conclude that surgery definitively reduces the risk of esophageal and gastric cancers, he says. For example, if some patients stopped or reduced smoking and alcohol use after surgery, they would lower their risk of squamous cell carcinoma, which, unlike adenocarcinoma, is associated with smoking and drinking but not obesity.
Despite its limitations, however, the study may help inform treatment. “We can say with great certainty based on these results that in a large group of patients who underwent bariatric surgery, esophageal and gastric cancer did not increase in the first 5 to 6 years,” Islami says. “That offers an extra layer of reassurance for patients and physicians when weighing the potential harms versus benefits of a bariatric procedure.” –Janet Colwell
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