Gastroesophageal reflux disease (GERD) is associated with a higher risk of squamous cancers of the larynx and esophagus, according to results of a large prospective study. Roughly 17% of these cancers may be linked to GERD, Dr. Christian Abnet of the National Cancer Institute and colleagues report in the journal Cancer. The association between GERD and Barrett's esophagus, a precursor to esophageal cancer, is well known. Prior studies have suggested that GERD may be associated with laryngeal squamous-cell carcinoma (LSCC) and esophageal squamous-cell carcinoma (ESCC); however, most of these studies had methodological limitations or didn't control adequately for potential confounders, the researchers point out. They examined the association between GERD and risk of esophageal adenocarcinoma (EADC), LSCC and ESCC in more than 490,000 participants in the NIH-AARP Diet and Health Study cohort who were between 50 and 71 years old at baseline. An estimated 24% of participants had a history of GERD. Over 16 years of follow-up, 931 cases of EADC, 876 cases of LSCC, and 301 cases of ESCC were recorded. In multivariable analysis, GERD was associated with a significantly higher risks of EADC (hazard ratio, 2.23; 95% confidence interval, 1.72 to 2.90), LSCC (HR, 1.91; 95% CI, 1.24 to 2.94) and ESCC (HR, 1.99; 95% CI, 1.39 to 2.84). The associations were independent of sex, smoking status, alcohol intake, and follow-up time periods. The research team also estimates that 22% of the general U.S. population aged 50 to 71 years suffered from GERD in 2015. Using national risk-factor-survey data, they estimate that 16.9% of LSCC cases and 17.3% of ESCC cases among individuals in this age range were associated with GERD. "Few studies have investigated the association between GERD and ESCC. Our results add robust prospective evidence for an adverse association between GERD and EADC and ESCC," Dr. Abnet and colleagues say. "To our knowledge," they add, "this is the largest prospective study to investigate the associations between GERD and LSCC and the first prospective study to report an association between GERD and ESCC. Future prospective studies with validated GERD questionnaires or endoscopy-proven GERD paired with comprehensive control for confounding are needed to replicate these findings." If replicated in future prospective studies, the findings "may inform clinical surveillance of GERD patients and suggest new avenues for prevention of these malignancies," they conclude. "This study alone is not sufficient to result in specific actions by the public. Additional research is needed to replicate these findings and establish GERD as a risk factor for cancer and other diseases," Dr. Abnet said in a news release. "Future studies are needed to evaluate whether treatments aimed at GERD symptoms will alter the apparent risks." This study was supported by the Intramural Research Program of the National Cancer Institute. The authors declared no conflicts of interest. —Reuters Staff Source
