title: Interobserver Reproducibility of Histological Grading of Canine Simple Mammary Carcinomas.
abstract: Histological grading of canine mammary carcinomas (CMCs) has been performed using an adaptation of the human Nottingham method. The histological grade could be a prognostic factor in CMC; however, no data are available concerning interobserver variability in grading. In this study we analyzed the interobserver reproducibility between three observers when assigning individual parameter scores and grade to 46 CMCs. The influence of tumour size and vascular invasion and/or lymph node metastases on the odds of grading disagreement was also evaluated. The mean kappa values were 0.71, 0.51, 0.69 and 0.70 for tubule formation, nuclear pleomorphism, mitotic counts and grade, respectively. There was moderate to good agreement in scoring parameters and tumour grading, with nuclear pleomorphism being least reproducible. These findings are similar to those of human studies. The odds of grading disagreement increased with tumour size, but decreased with the presence of vascular invasion and/or lymph node metastases. Individual scoring differences were moderated by reaching a consensus between two observers.
authors.affiliation: Department of Microscopy, Instituto Ciências Biomédicas Abel Salazar, University of Porto, Porto, Portugal. Electronic address: mssantos@icbas.up.pt.
authors.forename: M
authors.initials: M
authors.lastname: Santos
authors.affiliation: Epidemiology Research Unit, Future Farming Systems, Scotland's Rural College, Edinburgh, UK.
authors.forename: C
authors.initials: C
authors.lastname: Correia-Gomes
authors.affiliation: Faculty of Veterinary Medicine, Lusófona University of Humanities and Technologies, Lisbon, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Santos
authors.affiliation: Department of Veterinary Clinics, Instituto Ciências Biomédicas Abel Salazar, University of Porto, Porto, Portugal; Animal Science and Study Central, Food and Agrarian Sciences and Technologies Institute, University of Porto, Porto, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: de Matos
authors.affiliation: Department of Pathology and Molecular Immunology, Instituto Ciências Biomédicas Abel Salazar, University of Porto, Porto, Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Dias-Pereira
authors.affiliation: Department of Pathology and Molecular Immunology, Instituto Ciências Biomédicas Abel Salazar, University of Porto, Porto, Portugal.
authors.forename: C
authors.initials: C
authors.lastname: Lopes
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005260:Female; D015674:Mammary Neoplasms, Animal / Q000473:pathology*; D060787:Neoplasm Grading / Q000379:methods*; D015588:Observer Variation; D015203:Reproducibility of Results
keywords: canine mammary tumours; grade; reproducibility