title: Treatment strategy for synchronous metastases of colorectal cancer: is hepatic resection after an observation interval appropriate?
abstract: BACKGROUND
  In cases of synchronous colorectal hepatic metastases, the primary colorectal cancer strongly influences on the metastases. Our treatment policy has been to conduct hepatic resection for the metastases at an interval of 3 months after colorectal resection. We examined the appropriateness of interval hepatic resection for synchronous hepatic metastasis.
  
  
  METHODS
  The subjects were 164 patients who underwent resection of hepatic metastasis of colorectal cancer (synchronous, 70 patients; metachronous, 94 patients). Background factors for hepatic metastasis and postoperative results were compared for synchronous and metachronous cases.
  
  
  RESULTS
  The cumulative survival rate for 164 patients at 3, 5, and 10 years postoperatively was 71.9%, 51.8%, and 36.6%, and the post-resection recurrence rate in remnant livers was 26.8%. Interval resection for synchronous hepatic metastases was conducted in 49 cases after a mean interval of 131 days. No difference was seen in postoperative outcome between synchronous and metachronous cases.
  
  
  CONCLUSIONS
  The outcome was similarly favorable in cases of synchronous hepatic metastasis and in cases of metachronous metastasis. Delaying resection allows accurate understanding of the number and location of hepatic metastases, and is beneficial in determining candidates for surgery and in selecting surgical procedure.
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Kanokoden 1-1, Chikusa-ku, Nagoya, 464-8681, Japan. yshimizu@aichi-cc.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Kenzo
authors.initials: K
authors.lastname: Yasui
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Sano
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirai
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Kanemitsu
authors.forename: Koji
authors.initials: K
authors.lastname: Komori
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Kato
mesh_terms: D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D006498:Hepatectomy; D006801:Humans; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000401:mortality / Q000473:pathology / Q000556:secondary* / Q000601:surgery*; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology / Q000601:surgery; D019370:Observation; D011379:Prognosis; D016016:Proportional Hazards Models; D012086:Reoperation; D012189:Retrospective Studies; D015996:Survival Rate