Studies exist that link acid-reflux conditions to cancer of the larynx — or voice box — but authors of a new study say they all suffer shortcomings in methodology.

The new study, published in the American Journal of Medicine, was intended to make up for these shortcomings by comparing 96 men and women with laryngeal cancer to a group of adults without the disease. All participants were matched by age, gender, and ethnicity — three of the most important risk factors for this cancer. Overall, the study found people with GERD — gastroesophageal reflux disease — were twice as likely to develop laryngeal cancer, compared to those without the condition. GERD has long been considered a possible risk factor for this cancer, mostly because GERD is common among people with the cancer. More definitive studies are on the horizon.

GERD, which occurs when the muscle of the bottom of the esophagus fails to close properly, allowing stomach acids to leak into the esophagus, is also linked to esophageal cancer.