title: Survival of patients with colorectal peritoneal metastases is affected by treatment disparities among hospitals of diagnosis: A nationwide population-based study.
abstract: In the Netherlands, surgery for peritoneal metastases of colorectal cancer (PMCRC) is centralised, whereas PMCRC is diagnosed in all hospitals. This study assessed whether hospital of diagnosis affects treatment selection and overall survival (OS).
  
  
  
  Between 2005 and 2015, all patients with synchronous PMCRC without systemic metastases were selected from the Netherlands Cancer Registry. Treatment was classified as cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC), systemic therapy or other/no treatment. Hospitals of diagnosis were classified as: (1) non-teaching or academic/teaching hospital and (2) HIPEC centre or referring hospital. Referring hospitals were further classified based on the frequency of CRS/HIPEC as high-, medium- or low-frequency hospital. Multivariable regression analyses were used to assess the independent influence of hospital categories on the likelihood of CRS/HIPEC and OS.
  
  
  
  A total of 2661 patients, diagnosed in 89 hospitals, were included. At individual hospital level, CRS/HIPEC and systemic therapy ranged from 0% to 50% and 6% to 67%, respectively. Hospital of diagnosis influenced the likelihood of CRS/HIPEC: 33% versus 13% for HIPEC centres versus referring hospitals (odds ratio (OR) 3.66 [2.40-5.58]) and 11% versus 17% for non-teaching hospitals versus academic/teaching hospitals (OR 0.60 [0.47-0.77]). Hospital of diagnosis affected median OS: 14.1 versus 9.6 months for HIPEC centres versus referring hospitals (hazard ratio (HR) 0.82 [0.67-0.99]) and 8.7 versus 11.5 months for non-teaching hospitals versus academic/teaching hospitals (HR 1.15 [1.06-1.26]). Compared with diagnosis in medium-frequency referring hospitals, median OS was increased in high-frequency referring hospitals (12.6 months, HR 0.82 [0.73-0.91]) and reduced in low-frequency referring hospitals (8.1 months, HR 1.12 [1.01-1.24]).
  
  
  
  Treatment disparities among hospitals of diagnosis and their impact on survival indicate suboptimal treatment selection for PMCRC.
authors.affiliation: Department of Surgery, Catharina Hospital, PO Box 1350, 5602 ZA, Eindhoven, The Netherlands.
authors.forename: Koen P
authors.initials: KP
authors.lastname: Rovers
authors.affiliation: Department of Surgery, Catharina Hospital, PO Box 1350, 5602 ZA, Eindhoven, The Netherlands.
authors.forename: Geert A
authors.initials: GA
authors.lastname: Simkens
authors.affiliation: Department of Research, Netherlands Comprehensive Cancer Organisation (IKNL), PO Box 19079, 3501 DB, Utrecht, The Netherlands.
authors.forename: Pauline A
authors.initials: PA
authors.lastname: Vissers
authors.affiliation: Department of Research, Netherlands Comprehensive Cancer Organisation (IKNL), PO Box 19079, 3501 DB, Utrecht, The Netherlands; Department of Public Health, Erasmus Medical Centre, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.
authors.forename: Valery E
authors.initials: VE
authors.lastname: Lemmens
authors.affiliation: Department of Surgery, Aarhus University Hospital, Norrebrogade 44, DK-8000, Aarhus, Denmark.
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Verwaal
authors.affiliation: Department of Surgery, Radboud University Medical Centre, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: Andre J
authors.initials: AJ
authors.lastname: Bremers
authors.affiliation: Department of Surgery, Sint Antonius Hospital, PO Box 2500, 3430 EM, Nieuwegein, The Netherlands.
authors.forename: Marinus J
authors.initials: MJ
authors.lastname: Wiezer
authors.affiliation: Department of Surgery, Erasmus Medical Centre, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.
authors.forename: Jacobus W
authors.initials: JW
authors.lastname: Burger
authors.affiliation: Department of Surgery, University Medical Centre Groningen, PO Box 30001, 9700 RB, Groningen, The Netherlands.
authors.forename: Patrick H
authors.initials: PH
authors.lastname: Hemmer
authors.affiliation: Department of Gastroenterology and Hepatology, Antoni van Leeuwenhoek Hospital, PO Box 90203, 1006 BE, Amsterdam, The Netherlands.
authors.forename: Henk
authors.initials: H
authors.lastname: Boot
authors.affiliation: Department of Surgery, University Medical Centre Utrecht, PO Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Wilhelmina M
authors.initials: WM
authors.lastname: van Grevenstein
authors.affiliation: Department of Surgery, VU University Medical Centre, PO Box 7057, 1007 MB, Amsterdam, The Netherlands.
authors.forename: Wilhelmus J
authors.initials: WJ
authors.lastname: Meijerink
authors.affiliation: Department of Surgery, Antoni van Leeuwenhoek Hospital, PO Box 90203, 1006 BE, Amsterdam, The Netherlands.
authors.forename: Arend G
authors.initials: AG
authors.lastname: Aalbers
authors.affiliation: Department of Medical Oncology, Academic Medical Centre, PO Box 22660, 1100 DD, Amsterdam, The Netherlands.
authors.forename: Cornelis J
authors.initials: CJ
authors.lastname: Punt
authors.affiliation: Department of Surgery, Academic Medical Centre, PO Box 22660, 1100 DD, Amsterdam, The Netherlands.
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: Tanis
authors.affiliation: Department of Surgery, Catharina Hospital, PO Box 1350, 5602 ZA, Eindhoven, The Netherlands. Electronic address: ignace.d.hingh@catharinaziekenhuis.nl.
authors.forename: Ignace H
authors.initials: IH
authors.lastname: de Hingh
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003110:Colonic Neoplasms; D005260:Female; D054625:Healthcare Disparities / Q000706:statistics & numerical data; D006760:Hospitalization / Q000706:statistics & numerical data; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D010534:Peritoneal Neoplasms / Q000401:mortality / Q000556:secondary / Q000628:therapy*; D012004:Rectal Neoplasms; D012959:Socioeconomic Factors
keywords: Colorectal neoplasms; Colorectal surgery; Cytoreduction surgical procedures; Health services research; Hospitals; Peritoneal lavage; Peritoneal neoplasms; Quality of health care; Survival