title: Recommendations and consensus on the treatment of peritoneal metastases of colorectal origin: a systematic review of national and international guidelines.
abstract: OBJECTIVE
  This systematic review aimed to provide an overview of (inter)national guidelines on the treatment of peritoneal metastases of colorectal cancer origin (PMCRC) and to determine the degree of consensus and available evidence with identification of topics for future research.
  
  
  METHODS
  A systematic search of MEDLINE, Embase, PubMed as well as Tripdatabase, National Guideline Clearinghouse, BMJ Best Practice and Guidelines International Network was performed to identify (inter)national guidelines and consensus statements from oncological or surgical societies on PMCRC. The quality of guidelines was assessed using the AGREE-II score. Topics followed by recommendations were extracted from the guidelines. The recommendations, highest level of supporting evidence and the degree of consensus were determined for each topic.
  
  
  RESULTS
  Twenty-one guidelines were included, in most (15) of which cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) was recommended in selected patients based on level 1b evidence. Substantial consensus was also reached on the benefit of multidisciplinary team discussion and the achievability of a (near) complete cytoreduction (CC0-1) without supporting evidence. Both evidence and consensus were lacking regarding other aspects including preoperative positron emission tomography/CT, second look surgery in high risk patients, the optimal patient selection for CRS/HIPEC, procedural aspects of HIPEC and (perioperative) systemic therapy.
  
  
  CONCLUSIONS
  In currently available guidelines, evidence and consensus on the treatment strategy for PMCRC are lacking. Updates of guidelines are ongoing and future (randomized) clinical trials should contribute to multidisciplinary and international consensus on treatment strategies for PMCRC.
authors.affiliation: Department of Surgery, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: C E L
authors.initials: CE
authors.lastname: Klaver
authors.affiliation: Department of Surgery, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: Groenen
authors.affiliation: Academic Department of Surgery, University of Birmingham, Edgbaston, Birmingham, UK.
authors.forename: D G
authors.initials: DG
authors.lastname: Morton
authors.affiliation: Department of Surgical Gastroenterology, Aarhus University, Aarhus C, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Laurberg
authors.affiliation: Department of Surgery, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: W A
authors.initials: WA
authors.lastname: Bemelman
authors.affiliation: Department of Surgery, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: P J
authors.initials: PJ
authors.lastname: Tanis
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002277:Carcinoma / Q000556:secondary / Q000628:therapy*; D015179:Colorectal Neoplasms / Q000473:pathology*; D003131:Combined Modality Therapy; D065426:Cytoreduction Surgical Procedures; D006801:Humans; D006979:Hyperthermia, Induced; D007263:Infusions, Parenteral; D018579:Patient Selection; D010534:Peritoneal Neoplasms / Q000556:secondary / Q000628:therapy*; D017410:Practice Guidelines as Topic; D024162:Second-Look Surgery
chemical_list: D000970:Antineoplastic Agents
keywords: Colorectal cancer; guidelines; peritoneal metastases