title: Peritoneal carcinomatosis of colorectal origin: incidence and current treatment strategies.
abstract: OBJECTIVE
  To review the literature with regard to the incidence and prognostic significance of peritoneal seeding during surgery for primary colorectal cancer (CRC), the incidence of intraperitoneal recurrence of CRC, and the current treatment strategies of established PC of colorectal origin, with special focus on cytoreductive surgery and intraperitoneal chemotherapy (IPEC).
  
  
  BACKGROUND
  Although hematogenous dissemination forms the greatest threat to patients with CRC, peritoneal carcinomatosis (PC), presumably arising from intraperitoneal seeding of cancer cells, is a relatively frequent event in patients with recurrent CRC.
  
  
  METHODS
  The PubMed and Medline literature databases were searched for pertinent publications regarding the incidence and prognostic significance of exfoliated tumor cells in the peritoneal cavity during curative surgery for primary CRC, the incidence of intraperitoneal recurrence of CRC, and the therapeutic results of systemic chemotherapy or cytoreductive surgery followed by IPEC.
  
  
  RESULTS
  The incidence of peritoneal seeding during potentially curative surgery for primary CRC, as reported in 12 patient series, varied widely, from 3% to 28%, which may be explained by differences in methods to detect tumor cells. PC is encountered in approximately 7% of patients at primary surgery, in approximately 4% to 19% of patients during follow-up after curative surgery, in up to 44% of patients with recurrent CRC who require relaparotomy, and in 40% to 80% of patients who succumb to CRC. The reported median survival after systemic 5-fluorouracil-based chemotherapy for PC varies from 5.2 to 12.6 months. Median survival after aggressive cytoreductive surgery followed by (hyperthermic) IPEC in selected patients, as reported in 16 patient series, tends to be better and varies from 12 to 32 months at the cost of morbidity and mortality rates of 14% to 55% and 0% to 19%, respectively. One randomized controlled trial has been published confirming the superiority of aggressive surgical cytoreduction and intraperitoneal chemotherapy over strictly palliative treatment.
  
  
  CONCLUSIONS
  Peritoneal seeding of cancer cells possibly leading to PC is a rather common phenomenon in patients with CRC. Cytoreductive surgery and adjuvant (hyperthermic) IPEC have been shown to be efficacious in selected patients and should therefore be considered in patients with resectable PC of colorectal origin.
authors.affiliation: Department of Surgery, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands. m.koppe@chir.umcn.nl
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: Koppe
authors.forename: Otto C
authors.initials: OC
authors.lastname: Boerman
authors.forename: Wim J G
authors.initials: WJ
authors.lastname: Oyen
authors.forename: Robert P
authors.initials: RP
authors.lastname: Bleichrodt
mesh_terms: D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use; D002277:Carcinoma / Q000188:drug therapy / Q000453:epidemiology* / Q000556:secondary* / Q000601:surgery*; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery; D003131:Combined Modality Therapy; D005472:Fluorouracil / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D015994:Incidence; D002955:Leucovorin / Q000009:adverse effects / Q000627:therapeutic use; D009366:Neoplasm Seeding; D010534:Peritoneal Neoplasms / Q000188:drug therapy / Q000453:epidemiology* / Q000556:secondary* / Q000601:surgery*; D011183:Postoperative Complications; D011379:Prognosis; D011788:Quality of Life; D016019:Survival Analysis
chemical_list: D000970:Antineoplastic Agents; D002955:Leucovorin; D005472:Fluorouracil