Is the risk of idiopathic sudden sensorineural hearing loss higher in nasopharyngeal carcinoma than in hypopharyngeal cancer? A population-based study

Background: The aim of this study was to compare the risk of developing sudden sensorineural hearing loss (SSHL) in patients with hypopharyngeal cancer with that in patients with nasopharyngeal carcinoma (NPC). Methods: A population-based, retrospective cohort study was performed using the Taiwan National Health Research Database databank. Patients selected for this study were diagnosed with hypopharyngeal cancer or NPC and treated with radiotherapy in the period from 2001 to 2004. Routine follow-up was conducted for 8 years (2004–2012), and the incidence of SSHL was calculated at the final follow-up. Results: There was no significant difference in the risk of developing SSHL between the hypopharyngeal cancer group and its control group (p = 1.000). In hypopharyngeal cancer and NPC groups, the rates of SSHL were 0.12% and 1.00%, respectively (p < 0.001). The cumulative hazard of SSHL during the follow-up period was significantly higher in the NPC group than in the control group (p < 0.001). Conclusion: Radiotherapy in patients with hypopharyngeal cancer did not increase the risk of developing SSHL, but postirradiation NPC was significantly associated with an increased incidence of SSHL.