title: Factors affecting recurrence and prognosis after R0 resection for colorectal cancer with peritoneal metastasis.
abstract: BACKGROUND
  Peritoneal metastases (PM) are a well-known poor prognostic factor. The aim of this study was to investigate the factors affecting recurrence and prognosis after R0 resection for colorectal cancer with synchronous peritoneal metastases.
  
  
  METHODS
  We conducted a multi-institutional retrospective analysis of 72 patients without distant metastases who underwent R0 surgery between 1991 and 2007 for colorectal cancer with PM localized to the adjacent peritoneum. Clinicopathological variables were analyzed for their significance to recurrence and prognosis.
  
  
  RESULTS
  Recurrence was found in 51 patients (70.8%) after R0 surgery. In logistic regression analyses, lymph node metastasis was shown to be an independent factor affecting recurrence. Non-intensive or no postoperative chemotherapy and eight or fewer dissected lymph nodes were identified as independent poor prognostic factors using the Cox proportional hazards model. Among patients who received postoperative chemotherapy, prognosis was significantly better in those who received intensive adjuvant chemotherapy using camptothecin-11 or oxaliplatin after R0 surgery than in those who received non-intensive chemotherapy. Among 47 patients whose recurrence date was known, 33 patients (70.2%) experienced recurrence within 18 months after R0 surgery for peritoneal metastases, and hematogenous recurrence was observed significantly more often than peritoneal recurrence.
  
  
  CONCLUSIONS
  Harvesting of more than eight lymph nodes and administration of intense adjuvant chemotherapy after R0 surgery are recommended for greater prediction accuracy and improved prognosis. Intensive follow-up should be performed within 18 months after R0 surgery for colorectal cancer with synchronous peritoneal metastases.
authors.affiliation: Department of Surgery, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kustukake-cho, Toyoake, Aichi, 470-1192, Japan. harsato@hotmail.co.jp.
authors.forename: Harunobu
authors.initials: H
authors.lastname: Sato
authors.affiliation: Department of Surgery, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kustukake-cho, Toyoake, Aichi, 470-1192, Japan.
authors.forename: Koutaro
authors.initials: K
authors.lastname: Maeda
authors.affiliation: Department of Surgery, Tochigi Cancer Center, Utsunomiya, Japan.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Kotake
authors.affiliation: Department of Surgery, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sugihara
authors.affiliation: Department of Medical Statistics, Fujita Health University School of Medicine, Toyoake, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017024:Chemotherapy, Adjuvant / Q000379:methods; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D010534:Peritoneal Neoplasms / Q000473:pathology* / Q000556:secondary / Q000628:therapy; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies
keywords: Colorectal cancer; Peritoneal metastases; Prognosis; R0 surgery; Recurrence