Gastric reflux is a risk factor for cancers of the pharynx and larynx, and the use of antacids seems to lower that risk, according to an observational study in Cancer Epidemiology, Biomarkers and Prevention.
In a multicenter collaboration, researchers matched some 630 cases of laryngopharyngeal squamous cell carcinomas with twice the number of controls without cancer. Analyses were adjusted for demographics, smoking history, and HPV16 seropositivity.
Among patients who were not heavy smokers or drinkers, a history of self-reported frequent heartburn was significantly associated with throat cancers relative to those without heartburn (odds ratio, 1.78). Use of antacids for heartburn was associated with a lower risk (OR, 0.59). However, there was no such inverse association seen with the use of proton-pump inhibitors or histamine H2 receptor antagonists — possibly due to confounding from increased disease severity leading to their use.
The authors speculate that acid reflux may cause cancers by, for example, inducing chronic inflammation or activating signaling pathways of cellular proliferation.