title: Prognostic value and interobserver agreement of endoscopic ultrasonography for superficial squamous cell carcinoma of the esophagus: a prospective study.
abstract: OBJECTIVE
  Submucosal invasion of superficial esophageal cancer (SEC) is related to the prognosis. We prospectively analyzed outcomes of SEC in patients staged by endoscopic ultrasonography (EUS).
  
  
  METHODS
  We staged 31 endoscopically diagnosed SEC cases using a 20/15-MHz thin probe. The EUS tumor stage was classified as EUSM (limited within mucosa), EUS-SM (with submucosal invasion), or EUS-MP over (invading the muscularis propria or deeper). Lymph node metastasis and 2-yr survival were analyzed according to the EUS tumor stage in 29 squamous cell carcinoma cases. Interobserver agreement of the EUS stage was tested between the examiner and a blind reviewer.
  
  
  RESULTS
  Lymph node metastasis was significantly frequent in the EUS-SM group (8 of 18 cases [44.4%]) compared with the EUS-M group (1 of 10 cases [10%]) (p = 0.03). Patient survival at 2 yr after initial therapy was 72.2% in the EUS-SM group and 90% in the EUS-M group. Death from cancer was noted only in the EUS-SM group (three cases). The accuracy rates of EUS tumor staging were 74.1% by the examiner and 66.7% by the blind reviewer, with moderate interobserver agreement (kappa = 0.46).
  
  
  CONCLUSIONS
  Thin-probe EUS can classify SEC into two groups: the EUS-M group with excellent outcome and the EUS-SM group with a significant risk of lymph node metastasis.
authors.affiliation: Department of Gastroenterology and Hepatology, Yamaguchi University School of Medicine, Minamikogushi, Ube, Japan. h.yanai@po.cc.yamaguchi-u.ac.jp
authors.forename: Hideo
authors.initials: H
authors.lastname: Yanai
authors.forename: Toshiya
authors.initials: T
authors.lastname: Harada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Okamoto
authors.forename: Atsuyoshi
authors.initials: A
authors.lastname: Hirano
authors.forename: Naori
authors.initials: N
authors.lastname: Takeo
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Yoshida
authors.forename: Kiwamu
authors.initials: K
authors.lastname: Okita
authors.forename: Toyokazu
authors.initials: T
authors.lastname: Kawano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology*; D019160:Endosonography; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging / Q000379:methods*; D015588:Observer Variation; D011379:Prognosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D016019:Survival Analysis