BMC Cancer (Nov 2012)

Mammographic density and inter-observer variability of pathologic evaluation of core biopsies among women with mammographic abnormalities

  • Trocchi Pietro,
  • Ursin Giske,
  • Kuss Oliver,
  • Ruschke Kathrin,
  • Schmidt-Pokrzywniak Andrea,
  • Holzhausen Hans-Jürgen,
  • Löning Thomas,
  • Thomssen Christoph,
  • Böcker Werner,
  • Kluttig Alexander,
  • Stang Andreas

DOI
https://doi.org/10.1186/1471-2407-12-554
Journal volume & issue
Vol. 12, no. 1
p. 554

Abstract

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Abstract Background As high percentage of mammographic densities complicates the assessment of imaging findings, mammographic density may influence the histopathological evaluation of core-biopsies of the breast. We measured the influence of mammographic density on the inter-observer variability of histopathological findings of breast biopsies. Methods Histological slides of 695 women who underwent core biopsies of the breast at University of Halle between 2006 and 2008 were evaluated in a blinded fashion by two pathologists using the five levels of the B-categorization scheme (B1-B5). To quantify mammographic density, we used a computer-based threshold method (Madena). We calculated observed and chance-corrected agreements (weighted kappa) and 95% confidence intervals (95% CI) according to four categories of mammographic density ( Results The weighted kappa decreased monotonically from 89.6% (95% CI: 85.8%, 93.3%) among women with less than 10% of mammographic density to 80.4% (95% CI: 69.9%, 90.9%) for women with more than 50% of mammographic density, respectively. Results of a kappa regression analysis showed that agreement of pathologists on clinically relevant categories (B1-B2 versus B3-B5) decreased with mammographic density. Conclusions Mammographic density is a relevant modifier of the agreement between pathologists who assess breast biopsies using the B-categorization scheme. The influence of mammographic density on the inter-observer variability can be explained to some extent by varying prevalences of histological entities across B categories that have typically different inter-observer agreement. Women with high mammographic density are at higher risk of inter-observer variability compared to women with low mammographic density and should possibly undergo a second pathology review.

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