Incidence of late-onset pneumonia in patients after treatment with radiotherapy for nasopharyngeal carcinoma: A nationwide population-based study.

Abstract

The purpose of this study was to assess the incidence of late-onset pneumonia in patients with nasopharyngeal carcinoma (NPC) after radiotherapy. Data were retrieved from the National Health Institute Research Database of Taiwan. We identified patients diagnosed with NPC (International Classification of Disease 9th revision-Clinical Modification [ICD-9-CM] code 147) from January 2005 to December 2008 who received curative radiotherapy as the study cohort. Incidences of pneumonia and related sequelae after 90 days of radiotherapy were calculated. A total of 3814 patients were enrolled in this study and 210 (5.5%) had late-onset pneumonia. The correlation coefficient between pneumonia and tube feeding was 0.332 (p < .001). The hazard ratio of pneumonia was 0.81 (95% confidence interval [CI] = 0.57-1.15) between patients with and without chemotherapy, and was 2.37 (95% CI = 1.73-3.24) between patients with and without re-radiation. Late-onset pneumonia is not uncommon in patients with NPC after radiotherapy. The risks of associated sequelae and mortality cannot be ignored.