title: Incidence of late-onset pneumonia in patients after treatment with radiotherapy for nasopharyngeal carcinoma: A nationwide population-based study.
abstract: BACKGROUND
  The purpose of this study was to assess the incidence of late-onset pneumonia in patients with nasopharyngeal carcinoma (NPC) after radiotherapy.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  Late-onset pneumonia is not uncommon in patients with NPC after radiotherapy. The risks of associated sequelae and mortality cannot be ignored.
authors.affiliation: Department of Otolaryngology, Taichung Veterans General Hospital, Taichung, Taiwan.|Graduate Institute of Natural Healing Sciences, Nanhua University, Chiayi, Taiwan.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Yen
authors.affiliation: Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Ching-Heng
authors.initials: CH
authors.lastname: Lin
authors.affiliation: Department of Otolaryngology, Taichung Veterans General Hospital, Taichung, Taiwan.|School of Medicine, Chung Shan Medical University, Taichung, Taiwan.
authors.forename: Rong-San
authors.initials: RS
authors.lastname: Jiang
authors.affiliation: Department of Radiation Oncology, Saint Martin De Porres Hospital, Chiayi, Taiwan.
authors.forename: Yi-Ting
authors.initials: YT
authors.lastname: Shih
authors.affiliation: Research Center for Traditional Chinese Medicine, Department of Medical Research and Department of Chinese Medicine, China Medical University Hospital, Taichung, Taiwan.|School of Chinese Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Hung-Rong
authors.initials: HR
authors.lastname: Yen
authors.affiliation: Department of Otolaryngology, Taichung Veterans General Hospital, Taichung, Taiwan.|Graduate Institute of Natural Healing Sciences, Nanhua University, Chiayi, Taiwan.|School of Medicine, National Yang-Ming Medical University, Taipei, Taiwan.
authors.forename: Kai-Li
authors.initials: KL
authors.lastname: Liang
mesh_terms: D000328:Adult; D002277:Carcinoma; D059186:Chemoradiotherapy, Adjuvant / Q000379:methods; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000628:therapy*; D011015:Pneumonia, Aspiration / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D018714:Radiotherapy, Adjuvant / Q000379:methods; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology
keywords: chemoradiotherapy; dysphagia; head and neck cancer; nasopharyngeal carcinoma; pneumonia