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The Validity of Registered Synchronous Peritoneal Metastases from Colorectal Cancer in the Danish Medical Registries

Authors Ravn S, Christiansen CF, Hagemann-Madsen RH, Verwaal VJ, Iversen LH

Received 11 November 2019

Accepted for publication 24 February 2020

Published 27 March 2020 Volume 2020:12 Pages 333—343


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 2

Editor who approved publication: Dr Vera Ehrenstein

Sissel Ravn,1 Christian F Christiansen,2 Rikke H Hagemann-Madsen,3 Victor J Verwaal,1 Lene H Iversen1,4

1Department of Surgery, Aarhus University Hospital, Aarhus, Denmark; 2Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 3Department of Pathology, Lillebaelt Hospital, Vejle, Denmark; 4Danish Colorectal Cancer Group (DCCG), Copenhagen, Denmark

Correspondence: Sissel Ravn
Department of Surgery, Aarhus University Hospital, Aarhus N DK-8200, Denmark
Tel +45 51627366

Introduction: Treatment options for peritoneal metastases (PM) from colorectal cancer (CRC) have increased, their efficiency should be monitored. For this purpose, register-based data on PM can be used, if valid.
Purpose: We aimed to evaluate the completeness and positive predictive value (PPV) of synchronous peritoneal metastases (S-PM) registered among CRC patients in the Danish National Patient Register (DNPR) and/or the Danish National Pathology Register (the DNPatR) using the Danish Colorectal Cancer Group database (DCCG) as a reference.
Patients and Methods: We identified Danish patients with newly diagnosed primary CRC in the DCCG during 2014– 2015. S-PM were routinely registered in the DCCG. We excluded patients with non-CRC cancers and identified S-PM using all three registries. We estimated the completeness and the PPV of registered S-PM in the DNPR, the DNPatR and the DNPR and/or the DNPatR (DNPR/DNPatR) in combination using the DCCG as the reference. We stratified by age, gender, WHO performance status, tumour location and distant metastases to liver and/or lungs.
Results: We identified 9142 patients with CRC in DCCG. In DCCG, 366 patients were registered with S-PM, among whom 213 in DCCG only, whereas 153 in DCCG and in at least one of DNPR and/or DNPatR. In DNPR/DNPatR, S-PM was registered with a completeness of 42% [95% CI: 37– 47] and a PPV of 60% [95% CI: 54– 66]. In the DNPR only, the completeness was 32% [95% CI: 27– 37] and the PPV 57% [95% CI: 50– 64]. The completeness in the DNPatR was 19% [95% CI: 15– 23] and the PPV was 76% [95% CI: 68– 85]. In the DNPR/DNPatR patients aged < 60 years (57% [95% CI: 46– 69]), patients with WHO performance status 0 (46% [95% CI: 37– 54]) and patients with no distant metastases (58% [95% CI: 50– 65]) were registered with a higher completeness.
Conclusion: Our algorithm demonstrates that the DNPR/DNPatR captures less than half of CRC patients with S-PM. Potential candidates for curative treatment options are registered with a higher completeness. Clinicians should be encouraged to register the presence of S-PM to increase the validity of register-based S-PM data.

Keywords: validity, synchronous peritoneal metastases, registries, colorectal cancer, epidemiology, completeness

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