title: Mucinous rectal cancer: effectiveness of preoperative chemoradiotherapy and prognosis.
abstract: BACKGROUND
  This study investigated the effects of preoperative chemoradiotherapy (PCRT) and the prognoses of patients with mucinous rectal cancer compared with those with nonmucinous cancer.
  
  
  METHODS
  We retrospectively reviewed the medical records of 368 patients who underwent curative resection after PCRT, between 2000 and 2006, for midrectal to lower-rectal adenocarcinoma. Mucinous cancers were present in 23 patients (6.3%) and nonmucinous cancers in 345. In each patient, clinical stage before chemoradiotherapy was compared with pathologic stage to evaluate the extent of downstaging. Survival and multivariate analyses were performed using clinicopathologic variables. The median follow-up period was 42 months (range, 4-105 months).
  
  
  RESULTS
  There was no difference in clinical stage between the groups. Although 58 patients (16.8%) in the nonmucinous group achieved pathologic complete responses (pCR), no mucinous group patient showed such a response. T-downstaging was more frequently observed in the nonmucinous than in the mucinous group (189 vs 7 [54.9% vs 30.4%], P = .03), but N-downstaging was similar in the 2 groups. The 5-year overall survival rate (OS) was significantly lower in the mucinous than in the nonmucinous group (64.8% vs 79.8%, P = .049). Multivariate analysis revealed that mucinous histotype was an independent (negative) prognostic factor for survival (hazard ratio, 2.36; 95% confidence interval, 1.05-5.3; P = .04).
  
  
  CONCLUSIONS
  Patients with mucinous rectal cancer experienced a lower rate of T-downstaging after PCRT and had a poorer prognosis than did patients with nonmucinous cancer.
authors.affiliation: Department of Surgery, Korea Institute of Radiological & Medical Sciences, Korea Cancer Center Hospital, Seoul, Korea.
authors.forename: Ui Sup
authors.initials: US
authors.lastname: Shin
authors.forename: Chang Sik
authors.initials: CS
authors.lastname: Yu
authors.forename: Jong Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Tae Won
authors.initials: TW
authors.lastname: Kim
authors.forename: Seok-Byoung
authors.initials: SB
authors.lastname: Lim
authors.forename: Sang Nam
authors.initials: SN
authors.lastname: Yoon
authors.forename: Yong Sik
authors.initials: YS
authors.lastname: Yoon
authors.forename: Chan Wook
authors.initials: CW
authors.lastname: Kim
authors.forename: Jin Cheon
authors.initials: JC
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000628:therapy*; D002288:Adenocarcinoma, Mucinous / Q000473:pathology / Q000628:therapy*; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D000069287:Capecitabine; D059248:Chemoradiotherapy; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000031:analogs & derivatives; D005500:Follow-Up Studies; D006801:Humans; D002955:Leucovorin / Q000008:administration & dosage; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000628:therapy*; D009367:Neoplasm Staging; D011300:Preoperative Care; D011446:Prospective Studies; D011878:Radiotherapy; D012004:Rectal Neoplasms / Q000473:pathology / Q000628:therapy*; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D003841:Deoxycytidine; D000069287:Capecitabine; D002955:Leucovorin; D005472:Fluorouracil