A new population-based study shows that those with gastric reflux are more likely to be diagnosed with cancers of the throat, including the voice box. The study, led by researchers at Brown University in Providence, RI, was in patients who had no history of smoking and infrequent alcohol use. Using antacids regularly, but not prescription medications, diminished the risk of throat cancer. Gastric reflux, a known cause of heartburn, was found to be an independent risk factor for throat cancer.
The study is published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
Scott M. Langevin, PhD, and colleagues analyzed 631 patients from a large case-controlled study in the Boston area. Four hundred and sixty-eight of the patients had throat cancer and 163 had vocal cord cancer. These patients were matched with 1,234 control subjects with no history of cancer. All participants filled out questionnaires on heartburn, smoking and drinking habits, as well as familial cancer history. The participants were also tested for infection with the human papillomavirus (HPV) 16, as HPV infection is linked to some types of head and neck cancers.
The study showed those with frequent heartburn, but no smoking or frequent alcohol use history, had a 78% higher risk for throat and vocal cord cancer.
It is estimated that approximately 52,610 patients were diagnosed with head and neck cancer and 11,500 died of their disease in 2012. Half of these cancers originate in the pharynx or larynx. Because these cancers are in the throat, treatment can be quite debilitating with patients having trouble with speaking, swallowing, and breathing.
Various types of head and neck cancer have been linked to infection with HPV, smoking, and frequent alcohol. The recent “Cancer Report to the Nation,” published in January 2013 noted a rise in HPV-related cancers including oropharyngeal cancers, a type of head and neck cancer. Other risk factors associated with the disease but understudied include diet, environmental hazards, and dental and oral hygiene.
Previous studies analyzed fewer numbers of patients and came to disparate conclusions on the link of gastric reflux and throat cancer. Taking antacids for heartburn relief reduced this risk by 41%. “This does not appear to be a sporadic finding as the observed protective effect was consistent across analyses regardless of smoking or drinking status, HPV 16 serology, or primary tumor site (including oral cancer),” state the authors.
Heartburn is the result of gastric acid flowing up into the esophagus and has been shown to be a major risk factor for esophageal cancer, but the gastric acid can also reach all the way into the larynx and pharynx. The acid can cause inflammation and damage the epithelium of the throat.
The authors do acknowledge that more studies are needed to rule out other factors not taken into account in the current study that could also explain the results. Langevin and colleagues state that the link between antacid use and cancer protection is plausible as antacids neutralize pH in the digestive tract which can hamper inflammation and reduce DNA damage caused by high acid levels.
“Additional studies are needed to validate the chemopreventive effects of antacids among patients with frequent heartburn,” said Langevin in a statement. “The identification of gastric reflux as a risk factor for throat and vocal cord cancers, however, may have implications in terms of risk stratification and identification of high-risk patients.”