title: Endoscopic evaluation of clinical response after preoperative chemoradiotherapy for lower rectal cancer: the significance of endoscopic complete response.
abstract: OBJECTIVE
  The management of rectal cancer is a significant oncologic challenge because rectal cancer has a poor prognosis among the various types of colorectal cancer. There have been several recent reports on a nonoperative approach for advanced lower rectal cancer, and this may be best for local disease control. However, objective evaluation of tumor response after preoperative chemoradiotherapy has not been standardized. The purpose of this study is to evaluate our method of endoscopic evaluation of complete response.
  
  
  METHODS
  This is a retrospective chart review. All patients received a long course of preoperative chemoradiotherapy (5-fluorouracil-based chemotherapy and 45-50.4 Gy) followed by radical surgical resection from May 2005 to March 2012 in The Cancer Institute Hospital of Japanese Foundation for Cancer Research. One hundred fifty-seven patients were reviewed consecutively. Criteria for endoscopic complete response were defined with a focus on the degree of ulcer healing and pit pattern without magnification.
  
  
  RESULTS
  Endoscopic CR (E-CR) evaluation with our definitions reflected histopathologic response evaluation with an accuracy of 91.7 %, sensitivity of 27.8 %, specificity of 100 %, positive predictive value (PPV) of 100 %, and negative predictive value (NPV) of 91.4 % (p < 0.001). Our criteria of E-CR led all cases of y-clinical CR (ycCR) to pathological CR.
  
  
  CONCLUSIONS
  Endoscopic evaluation focused on the degree of ulcer healing, and pit pattern without magnification is useful for judging ycCR.
authors.affiliation: Department of Gastroenterological Surgery, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, 3-8-31, Ariake, Koto-ku, Tokyo, 135-8550, Japan, atsushi.ogura@jfcr.or.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ogura
authors.forename: Akiko
authors.initials: A
authors.lastname: Chino
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Konishi
authors.forename: Takashi
authors.initials: T
authors.lastname: Akiyoshi
authors.forename: Teruhito
authors.initials: T
authors.lastname: Kishihara
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Tamegai
authors.forename: Masashi
authors.initials: M
authors.lastname: Ueno
authors.forename: Masahiro
authors.initials: M
authors.lastname: Igarashi
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery / Q000628:therapy*; D000328:Adult; D000368:Aged; D059186:Chemoradiotherapy, Adjuvant; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011351:Proctoscopy; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery / Q000628:therapy*; D012189:Retrospective Studies; D014456:Ulcer / Q000473:pathology