Improved DNA flow cytometric, DNA ploidy, and S‐phase reproducibility between 15 laboratories in analysis of breast cancer using generalized guidelines

Abstract

Background: Lack of generalized guidelines for DNA flow cytometric analysis (FCM) may be the main reason for its limited use in the clinical management of breast cancer. Methods: After an initial interlaboratory reproducibility study (Round I), we concluded that it was the evaluation of the DNA histograms rather than the technical performance of the analysis that was the main reason for discordant results between laboratories. Guidelines for the interpretation of DNA histograms were therefore drawn up. We present here data from a new reproducibility study (Round II) using these guidelines. Results: For 10 laboratories also participating in Round I, use of the guidelines increased the concordance in DNA ploidy status from 89% to 100% for the 46 samples used in both rounds. The concordance rate for SPF also increased; mean r s -value increased from 0.81 to 0.88, and mean kappa value

Cell proliferation, measured as flow cytometric S‐phase fraction, is a strong prognostic indicator in FIGO stage I endometrioid endometrial carcinoma: a population‐based study

“…As previously reported, our laboratory has improved the DNA flow cytometric protocol considerably, leading to more reliable and reproducible measurements of both DNA ploidy and SPF .…”

Tiling array-CGH for the assessment of genomic similarities among synchronous unilateral and bilateral invasive breast cancer tumor pairs

“…All samples were re-evaluated by a pathologist (DG) to confirm histological type and grade (Nottingham histological grade, NHG) [ 21 ] presence or absence of an intraductal component, vessel invasion (based on H&E stained sections), tumor size and nodal status, according to routine practice. Estrogen receptor (ER) and progesterone receptor (PgR) status were determined by enzyme immunoassay (fresh frozen tissue, according to Abbott Laboratories (Chicago, IL)), or by immunohistochemical assay (FFPE tissue), and routine DNA index (flow cytometric DNA analysis) was assessed prospectively according to standard procedures as previously described [ 22 - 24 ].…”

High-resolution genomic profiling of male breast cancer reveals differences hidden behind the similarities with female breast cancer

“…Flow cytometric DNA analysis on paraffin embedded tissue for the assessment of DNA index, DNA ploidy, and S-phase fraction was performed according to standard procedures as previously described [27].…”