title: Prognostic implication of mucinous histology in resected colorectal cancer liver metastases.
abstract: BACKGROUND
  Colorectal mucinous adenocarcinoma (MAC) is a subtype of colorectal adenocarcinoma with prominent mucin production associated with proximal location of tumor, advanced stage at diagnosis, microsatellite instability, and BRAF mutation. The prognostic implication of MAC in colorectal cancer liver metastases (CRCLM) is unknown. The purpose of our study was to determine the frequency and elucidate the prognostic implication of mucinous histology in CRCLM.
  
  
  METHODS
  The medical records of 118 patients who underwent CRCLM resection between 2000 and 2010 were reviewed. Clinicopathologic variables and outcome parameters were examined. Resected specimens were submitted to routine histologic evaluation. Patients were grouped according to the metastasis mucinous content: >50%, MAC; <50%, adenocarcinoma with intermediated mucinous component (AIM); and without any mucinous component, non-MAC (NMA).
  
  
  RESULTS
  Mean follow-up after resection was 37 months. Tumor recurrence was observed in 75% of patients. Overall survival and disease-free survival rates after hepatectomy were 61%, 56%, and 26%, 24% at 3 and 5 years, respectively. Tumors with mucinous component (AIM and MAC) were related to proximal location of the primary tumor and were more frequently observed in females. Multivariate analysis revealed that MAC was an independent negative prognostic factor (hazard ratio, 3.13; 95% CI, 1.30-6.68; P = .011) compared with non-MAC (NMA and AIM).
  
  
  CONCLUSIONS
  MAC has an adverse prognostic impact compared with NMA, which may influence therapeutic strategy raising an important subject for discussion and future investigation.
authors.affiliation: Liver Surgery Unit, Department of Gastroenterology, University of São Paulo Medical School, São Paulo, Brazil; Department of General, Visceral and Endocrine Surgery, Hôpital Pitié Salpetrière, Paris, France. Electronic address: rmlupinacci@gmail.com.
authors.forename: Renato Micelli
authors.initials: RM
authors.lastname: Lupinacci
authors.affiliation: Department of Pathology, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Evandro Sobroza
authors.initials: ES
authors.lastname: Mello
authors.affiliation: Liver Surgery Unit, Department of Gastroenterology, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Fabrício Ferreira
authors.initials: FF
authors.lastname: Coelho
authors.affiliation: Liver Surgery Unit, Department of Gastroenterology, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Jaime Arthur Pirolla
authors.initials: JA
authors.lastname: Kruger
authors.affiliation: Liver Surgery Unit, Department of Gastroenterology, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Marcos Vinícius
authors.initials: MV
authors.lastname: Perini
authors.affiliation: Liver Surgery Unit, Department of Gastroenterology, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Rafael S
authors.initials: RS
authors.lastname: Pinheiro
authors.affiliation: Liver Surgery Unit, Department of Gastroenterology, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Gilton Marques
authors.initials: GM
authors.lastname: Fonseca
authors.affiliation: Liver Surgery Unit, Department of Gastroenterology, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Ivan
authors.initials: I
authors.lastname: Cecconello
authors.affiliation: Liver Surgery Unit, Department of Gastroenterology, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: Herman
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006498:Hepatectomy; D006801:Humans; D008113:Liver Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis