title: Timing of resection for synchronous liver metastases from colorectal cancer.
abstract: BACKGROUND
  This study aimed to compare the surgical outcome and long-term survival between simultaneous and delayed resection of liver metastases from colorectal cancer (LM), and to identify the factors influencing hepatic disease-free survival in patients with synchronous LM.
  
  
  METHODS
  Seventy-four patients with LM were divided into two groups, i.e., 32 patients who underwent hepatectomy at the time of colorectal surgery (simultaneous group) and 42 patients who underwent delayed liver resection (delayed group).
  
  
  RESULTS
  The hepatic disease-free survival rates of patients from the delayed group with either ≥ 3 or <3 liver metastases were significantly better than that of the simultaneous group. Multivariate analysis showed that simultaneous resection was one of three independent prognostic indicators with an influence on hepatic disease-free survival. In 13 of the 42 (31%) patients from the delayed group, new metastatic lesions were found in the same and/or different segments after re-evaluation during the interval between operations. These patients had a higher incidence of poorly differentiated or mucinous adenocarcinoma, shorter interval between procedures, and larger tumors than patients without tumor progression.
  
  
  CONCLUSIONS
  Tumor progression could be recognized and occult metastases were detected during the interval between operations. Delayed resection of synchronous LM may be useful to reduce the risk of rapid recurrence in the remnant liver. Patients with poorly differentiated or mucinous adenocarcinoma and those with larger tumors who undergo delayed liver resection should receive neoadjuvant chemotherapy during the interval between operations.
authors.affiliation: Department of Surgery, Hirakata Hospital, Kansai Medical University, 2-3-1 Shinmachi, Hirakata, Osaka, Japan. kaibori@hirakata.kmu.ac.jp
authors.forename: Masaki
authors.initials: M
authors.lastname: Kaibori
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Iwamoto
authors.forename: Morihiko
authors.initials: M
authors.lastname: Ishizaki
authors.forename: Kosuke
authors.initials: K
authors.lastname: Matsui
authors.forename: Takamichi
authors.initials: T
authors.lastname: Saito
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yoshioka
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Hamada
authors.forename: A Hon
authors.initials: AH
authors.lastname: Kwon
mesh_terms: D000328:Adult; D000368:Aged; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008113:Liver Neoplasms / Q000097:blood / Q000401:mortality / Q000473:pathology / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D012307:Risk Factors; D016019:Survival Analysis; D013997:Time Factors