Feb. 22 (UPI) -- People with chronic heartburn may be twice as likely to develop throat and esophageal cancers than those without the condition, according to a study published Monday by the journal Cancer.
Among older adults, an estimated 17% of cases of esophageal adenocarcinoma, laryngeal squamous cell carcinoma and esophageal squamous cell carcinoma were linked with gastroesophageal reflux disease, or GERD, the data showed.
Laryngeal squamous cell carcinoma is a cancer of the larynx, or "voice box," while the others are diseases of the esophagus, the tube that connects the throat to the stomach.
However, "this study alone is not sufficient to result in specific actions by the public," study co-author Christian C. Abnet said in a statement.
"Additional research is needed to replicate these findings and establish GERD as a risk factor for cancer and other diseases," said Abnet, a researcher with the National Cancer Institute.
GERD, a gastrointestinal disorder that affects approximately 20% of all adults in the United States, occurs when stomach acid flows back into the esophagus, where it can cause tissue damage.
Previous studies have suggested that this damage may put patients at risk of developing a type of cancer called esophageal adenocarcinoma, the researchers said.
For this study, the National Cancer Institute researchers examined data on 490,605 adults enrolled in the National Institutes of Health-AARP Diet and Health Study, a survey of 3.5 million AARP members.
Participants were age 50 to 71 and lived in California, Florida, Louisiana, New Jersey, North Carolina or Pennsylvania or in the metropolitan areas of Atlanta and Detroit.
Based on Medicare claims data, about 24% of the study participants had a history of GERD, the data showed.
Over a period of 16 years, 931 participants developed esophageal adenocarcinoma, 876 developed laryngeal squamous cell carcinoma and 301 developed esophageal squamous cell carcinoma.
People with GERD had a two-times higher risk of developing each of these types of cancer, and the elevated risk was similar across groups categorized by sex, smoking status and alcohol consumption.
These findings were replicated in an analysis of Medicare claims data for 107,258 adults, according to the researchers.
About 30,000 people in the United States are diagnosed with cancers of the esophagus or throat each year, about 80% of them men, according to the American Cancer Society.
Although treatment has improved the prognosis associated with both forms of the disease, they remain among the most deadly cancers, with about 20% of those diagnosed surviving for five years or more.
"Future studies are needed to evaluate whether treatments aimed at GERD symptoms will alter the apparent risks," Abnet said.