The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Reproducibility in DNA flow cytometric analysis of breast cancer: comparison of 12 laboratories' results for 67 sample homogenates

På svenska

Author

  • Bo Baldetorp
  • Pär-Ola Bendahl
  • Mårten Fernö
  • Kalle Alanen
  • Ulla Delle
  • Ursula Falkmer
  • Britt Hansson-Aggesjö
  • Thomas Hockenström
  • Anders Lindgren
  • Lotta Mossberg
  • Stig Nordling
  • Helgi Sigurdsson
  • Olle Stål
  • Tapio Visakorpi
Show all

Summary, in English

Flow cytometric (FCM) DNA analysis yields information on ploidy status and the S-phase fraction (SPF), variables of prognostic importance in breast cancer. The clinical value of the SPF is currently being evaluated in prospective randomized trials. The widespread use of FCM DNA analysis emphasizes the importance of reproducibility (both intra- and interlaboratory). In this study, 67 nuclear suspensions of breast cancer samples were analyzed by 12 laboratories routinely performing FCM DNA analysis in breast cancer. No general guidelines were imposed; each laboratory used its own standard protocols. For DNA ploidy status (diploid vs. non-diploid), agreement was complete for 79% (53/67) of the samples, compared with 64% (43/67) of samples when tetraploidy was considered [i.e., euploid (diploid+tetraploid) vs. aneuploid (the remaining non-diploid)]. For the SPF, pairwise comparison of the results of all 12 laboratories yielded a mean Spearman's rank correlation of 0.78 (range: 0.54-0.93). For those 39 samples being categorized in low or high SPF by all laboratories, all agreed in 14 samples (36%). Similar patterns were obtained with kappa measures, agreement being good for ploidy status (diploid vs. non-diploid; overall kappa = 0.87 and 0.74 for euploid vs. aneuploid), but moderate for the SPF [overall kappa = 0.47 (for low SPF vs. high SPF vs. "no SPF reported")]. Discrepancies were chiefly attributable to differences in the categorization of the S-phase values, rather than in FCM procedures, other critical differences being in the detection and interpretation of near-diploid and small non-diploid cell populations, the definition of tetraploidy, and the choice and execution of the method used for S-phase estimation. Based on the observations of this study, detailed guidelines for FCM analysis and interpretation of data are proposed in the Appendix. Some issues remain, however, e.g., to standardize a method for S-phase calculation and tetraploid definition.

Publishing year

1995

Language

English

Pages

115-127

Publication/Series

Cytometry

Volume

22

Issue

2

Document type

Journal article

Publisher

John Wiley & Sons Inc.

Topic

  • Cancer and Oncology

Keywords

  • Interlaboratory
  • reproducibility
  • flow cytometry
  • DNA ploidy
  • S-phase
  • proliferation
  • quality control
  • standardization
  • breast cancer

Status

Published

ISBN/ISSN/Other

  • ISSN: 0196-4763