title: Anatomic sites at elevated risk of second primary cancer after an index head and neck cancer.
abstract: BACKGROUND
  Patients with head and neck squamous cell carcinoma (HNSCC) are at significantly elevated risk of second primary malignancies (SPM), most commonly within the head and neck, lung, and esophagus (HNLE). Our objectives were to quantify the excess risk of SPM across all anatomic sites in which SPM risk is meaningfully elevated, including non-HNLE sites, in a large cohort of US patients.
  
  
  METHODS
  Population-based analysis of 75,087 patients with HNSCC in the SEER program, quantifying excess SPM risk by integrating relative (standardized incidence ratio; SIR) and absolute (excess absolute risk per 10,000 person-years at risk; EAR) statistics.
  
  
  RESULTS
  In HNSCC patients, the SIR of a second primary solid cancer was 2.2 (95% CI 2.1-2.2), corresponding to EAR of 167.7 additional cases per 10,000 person-years at risk. Over 1 year, 60 patients would need to be followed to observe one excess SPM. Lung cancer burden was most markedly elevated in absolute terms (EAR = 75.2), followed by HN (EAR = 59.8), esophageal (EAR = 14.2), and colorectal (EAR = 4.3) cancers. Lesser but significant excess risks were also observed for cancers of the bladder, liver, stomach, pancreas, kidney, salivary glands, nasopharynx, uterine cervix, and lymphoma.
  
  
  CONCLUSIONS
  Data from a large population-based US cohort reveals that HNSCC patients experience markedly excess risk of SPM, predominantly in the HNLE sites. Furthermore, the risk of SPM is also meaningfully elevated, although to a lesser degree, in multiple other tobacco-associated sites.
authors.affiliation: Head and Neck Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA. morrisl@mskcc.org
authors.forename: Luc G T
authors.initials: LG
authors.lastname: Morris
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Sikora
authors.forename: Richard B
authors.initials: RB
authors.lastname: Hayes
authors.forename: Snehal G
authors.initials: SG
authors.lastname: Patel
authors.forename: Ian
authors.initials: I
authors.lastname: Ganly
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000473:pathology* / Q000556:secondary*; D015331:Cohort Studies; D005260:Female; D006258:Head and Neck Neoplasms / Q000453:epidemiology / Q000556:secondary*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000473:pathology*; D012307:Risk Factors; D018426:SEER Program; D014481:United States / Q000453:epidemiology