Cholecystectomy and risk of laryngeal and pharyngeal cancer

Duodeno-gastro-esophageal reflux of bile might cause laryngeal and pharyngeal cancer, but more research is required. Since cholecystectomy is followed by an increased risk such reflux, the risk of developing laryngeal or pharyngeal cancer after cholecystectomy was addressed. A population-based cohort study was conducted in Sweden during the period 1965-2008. The number of laryngeal or pharyngeal cancer cases observed in a large cohort of cholecystectomized patients was compared with the expected number, calculated from the entire Swedish population of corresponding age, gender and calendar year. Risk of laryngeal or pharyngeal cancer was calculated as standardized incidence ratio (SIR) with 95% confidence interval (CI). The cholecystectomy cohort included 345,251 patients who were followed up for 1-43 years and contributed 4,854,969 person-years at risk. The 192 new cases of laryngeal cancer and the 175 cases of pharyngeal cancer were not greater than the expected, providing SIR 0.99 (95% CI 0.85-1.14) and SIR 1.06 (95% CI 0.91-1.23), respectively. A longer latency period after cholecystectomy was not associated with any increased risk of any of these tumors. No differences between age groups or sexes were detected. Analyses restricted to verified squamous-cell carcinomas revealed similar results. In conclusion, cholecystectomy does not appear to be followed by any increased risk of laryngeal or pharyngeal cancer.