Risk of xerostomia in association with the receipt of radiation therapy in older patients with head and neck cancer

Abstract

The purpose of this study was to assess the incidence rate and risk of developing xerostomia in association with the receipt of radiation therapy (RT) among a large population-based cohort of elderly patients diagnosed with head and neck cancer (HNC). The study consisted of 10,387 men and women diagnosed with incident HNC cancer at age 65 years or older from 1991 through 2002, identified from the 16 registries of the Surveillance, Epidemiology and End Results-Medicare linked data. Patients were defined as having xerostomia if there were at least 2 claims (for diagnosis code 527.7) at 30 days apart after the date of HNC diagnosis. Patients receiving RT either with or without chemotherapy had a higher cumulative incidence of developing xerostomia compared with those with neither radiotherapy nor chemotherapy (5.6% and 3.8%, respectively vs. 0.5%) at a median follow-up of 2.4 years. Patients who received RT with concurrent chemotherapy were 9 times more likely to develop xerostomia (hazard ratio = 9.13, 95% confidence interval = 6.68-12.48) compared with patients who received neither RT nor chemotherapy, whereas those who received RT without chemotherapy were over 6 times more likely to develop xerostomia (6.29, 4.72-8.37). The strength of this association was similar when patients were stratified by tumor stage and anatomic tumor site. There was no significant association between the risk of developing xerostomia and ethnicity, marital, and socioeconomic status. Radiation therapy for the treatment of HNC is associated with a significant risk of developing xerostomia regardless of type of surgical treatment rendered, tumor stage, or anatomic tumor site.