title: High risk features of primary colorectal carcinomas which subsequently undergo peritonectomy.
abstract: Determine what portion of colorectal cancer (CRC) patients with peritoneal metastases (PM) undergoing peritonectomy would have been identified/treated if second-look surgery protocol existed for high-risk primary tumours.
  
  
  
  The prognosis of CRC PM greatly improves following peritonectomy/HIPEC. Survival remains dependent upon stage of PM and there is some knowledge of high-risk factors for its development. Subsequently, there is interest in routine second-look laparotomy to follow-up high-risk CRC patients so to 'prevent' PM.
  
  
  
  Patients were retrospectively selected from the St George database, all of whom had had PM recurrence after primary CRC resection thus underwent peritonectomy/HIPEC. Each patient's primary tumour pathology was obtained with incidence of high-risk stage (T4), macroscopic (peritoneal involvement, ovarian metastases, perforated primary) and microscopic (mucinous, signet ring) features noted.
  
  
  
  125 patients were included. At primary diagnosis, 34.4%, 46.4% and 19.2% were of T3, T4a and T4b stage. Primary tumour macroscopic features included 41.1%, 12.6% and 23.7% with synchronous peritoneal involvement, perforated primary and ovarian metastases. Primary tumour microscopic features included 8.1%, 44.0% and 5.6% with signet ring, mucinous and both pathologies. Individually T4 status, macroscopic and microscopic features would have identified 65.6%, 56.8% and 46.5% of patients. Any high-risk factor would have identified 85.6%.
  
  
  
  Our study suggests that T4 stage, high-risk macroscopic and high-risk microscopic features at time of primary diagnosis identifies the majority of CRC patients who later develop PM. This provides support for a selective second-look protocol in such patients to enable early identification and, potentially, 'prevention' of CRC PM.
authors.affiliation: University of New South Wales, Kensington, Sydney, NSW 2052, Australia. Electronic address: vannessa.leung@gmail.com.
authors.forename: V
authors.initials: V
authors.lastname: Leung
authors.affiliation: University of New South Wales, Kensington, Sydney, NSW 2052, Australia. Electronic address: nancy_huang17@hotmail.com.
authors.forename: N
authors.initials: N
authors.lastname: Huang
authors.affiliation: St George Hospital Department of Surgery, Gray St Kogarah, NSW 2217, Australia. Electronic address: winston.liauw@sesiahs.health.nsw.gov.au.
authors.forename: W
authors.initials: W
authors.lastname: Liauw
authors.affiliation: University of New South Wales, Kensington, Sydney, NSW 2052, Australia; St George Hospital Department of Surgery, Gray St Kogarah, NSW 2217, Australia. Electronic address: david.morris@unsw.edu.au.
authors.forename: D L
authors.initials: DL
authors.lastname: Morris
mesh_terms: D015179:Colorectal Neoplasms; D006801:Humans; D006979:Hyperthermia, Induced; D009364:Neoplasm Recurrence, Local; D010534:Peritoneal Neoplasms; D011379:Prognosis; D024162:Second-Look Surgery
keywords: Colorectal cancer; HIPEC; Peritoneal carcinomatosis; Peritoneal metastasis; Peritonectomy