title: Secondary oesophageal or gastric cancer in patients treated for head and neck squamous cell carcinoma.
abstract: BACKGROUND
  Patients with head and neck squamous cell carcinoma (HNSCC) are at an elevated risk of developing second primary malignancies (SPM). Our objectives were to estimate the excess risk of oesophageal and gastric SPMs in patients with malignancies of the pharynx or larynx and, additionally, to examine possible risk factors of developing SPMs.
  
  
  METHODS
  Data on all patients treated for HNSCC with curative intent in the Region of Southern Denmark in the period between 1 January 2000 and 31 December 2010 were reviewed. A total of 1,172 patients were identified. The combined data from the DAHANCA database, the Danish National Pathology Registry and the patient charts were analysed.
  
  
  RESULTS
  A total of 27 patients developed an SPM in the oesophagus or stomach corresponding to a standardised incidence ratio of 9.5 (95% confidence interval (CI): 6.5-13.9). Supraglottic (odds ratio (OR) = 6.9; p < 0.004) and hypopharyngeal (OR = 3.9; p < 0.049) index tumour sites were significant risk factors for developing SPM. The median survival of patients with SPM was 3.6 years (95% CI: 1.6-5.1; range: 0.7-12.4) from diagnosis of the index cancer compared with 3.4 years (95% CI: 3.1-4.3; range: 0.04-13.7) for patients without SPM.
  
  
  CONCLUSIONS
  In this study, we confirm that there is an elevated risk of developing oesophageal and gastric cancer in the Danish population of patients with a cancer in the supraglottic or hypopharyngeal region. Therefore, we recommend close follow-up of these patients and a low threshold for examination of the oesophagus and stomach.
  
  
  BACKGROUND
  not relevant.
  
  
  BACKGROUND
  not relevant.
authors.affiliation: anjarosenlundandersen@hotmail.com.
authors.forename: Anja Rosenlund
authors.initials: AR
authors.lastname: Andersen
authors.forename: Ole Steen
authors.initials: OS
authors.lastname: Bjerring
authors.forename: Christian
authors.initials: C
authors.lastname: Godballe
authors.forename: Sönke
authors.initials: S
authors.lastname: Detlefsen
authors.forename: Michael Bau
authors.initials: MB
authors.lastname: Mortensen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000628:therapy*; D003131:Combined Modality Therapy; D003718:Denmark / Q000453:epidemiology; D004938:Esophageal Neoplasms / Q000453:epidemiology*; D005260:Female; D006258:Head and Neck Neoplasms / Q000628:therapy*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors; D000077195:Squamous Cell Carcinoma of Head and Neck; D013274:Stomach Neoplasms / Q000453:epidemiology*