title: Clinical advantage of endoscopic submucosal dissection over endoscopic mucosal resection for early mesopharyngeal and hypopharyngeal cancers.
abstract: OBJECTIVE
  In previous series, endoscopic mucosal resection (EMR) has been used for the treatment of early-stage mesopharyngeal and hypopharyngeal cancers to preserve patients' quality of life. Endoscopic submucosal dissection (ESD) offers potential advantages in comparison to EMR. So the aim of this retrospective study was to assess the utility of ESD compared with EMR for early-stage cancers of the meso- and hypopharynx.
  
  
  METHODS
  We studied 56 patients with 69 lesions who underwent either EMR or ESD between April 2001 and December 2008. EMR was performed until January 2007, and ESD was performed from February 2007 onward. We evaluated the en bloc resection rate, R0 resection rate, and treatment-related complications as short-term outcomes. Local recurrence, lymph node metastasis, and disease-related deaths were compared to evaluate long-term outcomes.
  
  
  RESULTS
  The en bloc and R0 resection rates were respectively 98 % and 79 % in the ESD group and 37 % and 26 % in the EMR group. There were no cases of treatment-related complications in the EMR group, but postoperative subcutaneous emphysema was observed in two patients in the ESD group. In the EMR group, one patient developed a local recurrence and one developed metastasis to the cervical lymph node and died of primary cancer.
  
  
  CONCLUSIONS
  ESD is a useful method of treatment for early mesopharyngeal and hypopharyngeal cancers and may be superior to EMR.
authors.affiliation: Department of Gastroenterology, Toranomon Hospital, Tokyo, Japan. t-iizuka@toranomon.gr.jp
authors.forename: T
authors.initials: T
authors.lastname: Iizuka
authors.forename: D
authors.initials: D
authors.lastname: Kikuchi
authors.forename: S
authors.initials: S
authors.lastname: Hoteya
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: S
authors.initials: S
authors.lastname: Yamashita
authors.forename: T
authors.initials: T
authors.lastname: Mitani
authors.forename: H
authors.initials: H
authors.lastname: Takeda
authors.forename: N
authors.initials: N
authors.lastname: Yahagi
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000556:secondary / Q000601:surgery*; D004210:Dissection / Q000009:adverse effects; D004724:Endoscopy / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000473:pathology* / Q000601:surgery*; D007013:Hypopharynx / Q000601:surgery*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000601:surgery; D009364:Neoplasm Recurrence, Local / Q000209:etiology*; D010611:Pharyngectomy / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D013352:Subcutaneous Emphysema / Q000209:etiology