title: Histopathologic factors affecting tumor recurrence after hepatic resection in colorectal liver metastases.
abstract: OBJECTIVE
  Hepatic resection is a standard method of treatment for colorectal liver metastases (CRLM). However, the pathologic factors of metastatic lesions that affect tumor recurrence are less well defined in CRLM. The aim of this study was to evaluate the risk factors for recurrence of CRLM, focusing on histopathologic factors of metastatic lesions of the liver.
  
  
  METHODS
  From January 2003 to December 2008, 117 patients underwent curative hepatic resection for CRLM were reviewed. Tumor size and number, differentiation, tumor budding, angio-invasion, dedifferentiation and tumor infiltrating inflammation of metastatic lesions were investigated.
  
  
  RESULTS
  The mean number of hepatic tumors was 2 (range, 1-8). The mean size of the largest tumor was 2.9 cm (range, 0.3-18.5 cm) in diameter. The moderate differentiation of the hepatic tumor was the most common in 86.3% of the patients. Tumor budding, angio-invasion, and dedifferentiation were observed in 81%, 34%, and 12.8% of patients. Inflammation infiltrating tumor was detected in 6.8% of patients. Recurrence after hepatic resection appeared in 69 out of 117 cases (58.9%). Recurrence-free survival at 1, 2 and 5 years were 62.4%, 43.6%, and 34.3%. The multivariate analysis showed the number of metastases ≥3 (P = 0.007), the tumor infiltrating inflammation (P = 0.047), and presence of dedifferentiation (P = 0.020) to be independent risk factors for tumor recurrence.
  
  
  CONCLUSIONS
  Histopathological factors, i.e., dedifferentiation and tumor infiltrating inflammation of the metastatic lesion, could be one of the risk factors of aggressive behavior as well as the number of metastases even after curative resection for CRLM.
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Min-Su
authors.initials: MS
authors.lastname: Park
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Nam-Joon
authors.initials: NJ
authors.lastname: Yi
authors.affiliation: Department of Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Sang-Yong
authors.initials: SY
authors.lastname: Son
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Tae
authors.initials: T
authors.lastname: You
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Suk-Won
authors.initials: SW
authors.lastname: Suh
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Young Rok
authors.initials: YR
authors.lastname: Choi
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyeyoung
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Geun
authors.initials: G
authors.lastname: Hong
authors.affiliation: Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyoung Bun
authors.initials: KB
authors.lastname: Lee
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kwang-Woong
authors.initials: KW
authors.lastname: Lee
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seung-Yong
authors.initials: SY
authors.lastname: Jeong
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyu Joo
authors.initials: KJ
authors.lastname: Park
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyung-Suk
authors.initials: KS
authors.lastname: Suh
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Jae-Gahb
authors.initials: JG
authors.lastname: Park
keywords: Colorectal neoplasm; Hepatic resection; Inflammation; Liver metastasis; Recurrence