Researchers say the acid reflux surgery, as well as medication taken for the condition, seem to lower the risk of developing adenocarcinoma.

Acid reflux is the leading cause of cancer of the esophagus, but surgery designed to prevent acid reflux seems to reduce the risk of developing this aggressive and deadly form of cancer.

Up to 20 percent of adults suffer from chronic heartburn and acid reflux. Experts say persistent, severe reflux — the kind that occurs twice or more weekly — is a leading risk factor for esophageal cancer, also known as adenocarcinoma.

“There are many physicians who believe acid reflux and esophageal cancer are related,” Dr. Alex Little, a retired thoracic surgeon and currently a clinical professor at the University of Arizona School of Medicine, told Healthline. “We know that acid reflux is associated with, and probably induces, a change in the inner lining of the esophagus. This change is called Barrett’s esophagus. We also know that Barrett’s esophagus can further degenerate into esophageal cancer.”

“Stomach acid is a harsh chemical that is meant to stay in the place best designed to handle it — the stomach,” added Dr. Chirag Shah, an emergency medicine physician and co-founder of Accesa Labs in California, an online lab testing service. “Because the linings of the esophagus and throat are not well protected against acid in the way that the stomach is protected, the cells in the linings of the esophagus and the throat are easily damaged in the presence of stomach acid.”

Reflux generally is treated with medication designed to make the contents of the stomach less acidic.

Antireflux surgery, on the other hand, prevents stomach contents from coming up into the esophagus.

Both types of treatment seem to reduce the risk of esophageal cancer, according to a study of nearly 1 million people with reflux conducted over a 50-year period by researchers at the Karolinska Institutet in Sweden.

The study showed a drop in cancer cases after treatment with medication or surgery, with risk falling to the same level as the general population among people with reflux within 15 years of getting either type of intervention.

Karolinska Institutet researcher John Maret-Ouda, the first author of the study, said the study shows that “effective medical or surgical treatment of reflux prevents cancer of the esophagus.”

“Previous research results have shown poor cancer-preventive effects from antireflux surgery. The difference now is that for the first time we can show statistically significant results because we have a sufficiently large study with a long follow-up period of over 15 years following the operation,” added Dr. Jesper Lagergren, consultant surgeon and professor in the Department of Molecular Medicine and Surgery at the Karolinska Institutet.

Lagergren led the study, which was published in the journal JAMA Oncology.

The fact that similar results were seen, whether a surgical or a medical approach was pursued, “supports the theory that there is some pathological association between acid exposure on the esophageal lining and one’s predisposition to getting esophageal adenocarcinoma,” Shah told Healthline.

“This is undoubtedly true in some cases,” agrees Little. “The problem of interpretation is that only a minority of patients with Barrett’s esophagus actually get cancer, and many patients with cancer have no evidence of Barrett’s.”

“The picture is still muddy, but there is enough reason to worry that patients with symptoms of gastroesophageal reflux disease (GERD), mainly heartburn, receive an endoscopy to look for Barrett’s,” Little added.

One limitation of the research is that the population studied was entirely from Nordic countries, said Dr. Samuel Malloy, medical director at the United Kingdom-based online medical platform Dr. Felix.

“Esophageal cancer is not thought to have a genetic component, so this should not influence the results greatly, but other environmental and lifestyle factors of the population could impact the results,” Malloy told Healthline. “Nordic populations have lower rates of obesity and smoking than in the U.S., so the risk of esophageal cancer in Nordic countries may be lower than in the U.S. Therefore, the results may not be a true reflection of the U.S. situation, although due to the breadth of this study and the lengthy follow-up, it would be reasonable to expect similar results in the U.S.”

Individual risk of developing esophageal cancer is low, so “even in those with reflux disease, the results do not justify treating reflux solely as a cancer-preventive measure,” said Maret-Ouda.

Some treatments for reflux carry their own risks.

Long-term use of proton pump inhibitors, commonly used to control stomach acid, may increase the risk of infections, for example.

However, treating reflux as a cancer preventative might make sense for people with severe reflux who also had other strong risk factors for esophageal cancer, such as older, obese men, Maret-Ouda said.

Malloy noted that 59 percent of esophageal cancers are considered preventable.

“The majority of these preventable cases are related to smoking, alcohol, and obesity,” he said. “At first glance, this may look like there is little correlation with chronic acid reflux; however, smoking, alcohol, and obesity all are known to cause acid reflux.”