Increased risk of larynx cancer in patients with gastroesophageal reflux disease from a national sample cohort.

Abstract

The present study evaluated the associations between gastroesophageal reflux disease (GERD) and head and neck cancer using a national sample cohort of the Korean population. We designed two studies using data collected from patients aged ≥40years in the Korean National Health Insurance Service-National Sample Cohort from 2002 to 2013. Study I included participants with GERD matched 1:2 with controls and analysed the incidences of lip and oral cavity, oropharynx, hypopharynx and larynx cancers. Study II included participants with larynx cancer matched 1:4 with controls and analysed the previous histories of GERD. Head and neck cancer was identified using medical claim codes for surgical, radiation and chemotherapeutic treatments and death records from the National Statistical Office. Crude and adjusted hazard ratios (HRs) were analysed using the Cox proportional hazard model. Crude and adjusted odds ratios (ORs) were analysed using unconditional logistic regression analyses. Subgroup analyses were performed on groups stratified by age and sex. The adjusted HR for larynx cancer was 2.32 (95% confidence interval (CI)=1.53-3.52, P<0.001) in the GERD group. However, the HRs for lip and oral cavity cancer, oropharynx cancer and hypopharynx cancer were not statistically significant (study I). The adjusted OR for GERD was 2.03 (95% CI=1.40-2.96, P<0.001) in the larynx cancer group; consistent results were obtained in subgroup analyses. Gastroesophageal reflux disease increases the risk of larynx cancer.