title: Natural history of superficial head and neck squamous cell carcinoma under scheduled follow-up endoscopic observation with narrow band imaging: retrospective cohort study.
abstract: BACKGROUND
  The incidence rate has been increasing for superficial head and neck squamous cell carcinoma (HNSCC) discovered through surveillance endoscopic study using narrow band imaging (NBI), a procedure mainly used for high-risk patients with esophageal squamous cell carcinoma (ESCC). However, there are few reports on the natural history of superficial HNSCC. The aim of this retrospective study was to investigate the natural history of superficial HNSCC.
  
  
  METHODS
  From January 2007 to December 2012, 535 consecutive histologically confirmed superficial HNSCCs at the oropharynx, hypopharynx, or larynx in 319 patients were detected by endoscopic surveillance examination by using NBI. Of those, 20 untreated and observed lesions fulfilled the eligibility criteria and were analyzed in this study.
  
  
  RESULTS
  Twenty lesions from 17 patients were analyzed. All patients were men ranging from 52 to 86 years of age, with a median age of 69 years. The median endoscopic follow-up period was 20 months (range, 6-71); 17 lesions progressed in size. In this study, four patients died; the causes of death were synchronous ESCC, synchronous HNSCC, acute myocardial infarction, and unknown causes. No patient died from progression of superficial HNSCC.
  
  
  CONCLUSIONS
  Most superficial HNSCC has the potential to change progressively. Therefore, superficial HNSCC should be detected at an early stage and be treated less invasively, such as with endoscopic resection or partial resection.
authors.affiliation: Department of Gastroenterology, Endoscopy Division, National Cancer Center Hospital East, 6-5-1, Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakamura
authors.affiliation: Department of Gastroenterology, Endoscopy Division, National Cancer Center Hospital East, 6-5-1, Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan. toyano@east.ncc.go.jp.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Yano
authors.affiliation: Pathology Division, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujii
authors.affiliation: Department of Gastroenterology, Endoscopy Division, National Cancer Center Hospital East, 6-5-1, Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kadota
authors.affiliation: Department of Head and Neck Surgery, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Tomioka
authors.affiliation: Department of Head and Neck Surgery, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shinozaki
authors.affiliation: Department of Head and Neck Surgery, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Hayashi
authors.affiliation: Department of Gastroenterology, Endoscopy Division, National Cancer Center Hospital East, 6-5-1, Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kaneko