FLOW CYTOMETRIC MEASUREMENT OF DNA CONTENT IN HUMAN SOLID TUMORS - A COMPARISON WITH CYTOGENETICS

The aims of this study were: (1) to test the accuracy of flow cytometr y (FC) in the measurement of DNA content in human solid tumors, (2) to correlate the FC DNA-index (DI) with the chromosome modal number (CMN ) provided by cytogenetic analysis (CG), and (3) to investigate the mo st frequent pitfalls in FC histograms classification, FC and CG analys es were performed in parallel on 113 samples of human solid tumors of different origin, FC provided an evaluable histogram in 110 out of 113 cases (97%), whereas a successful CG culture was obtained in 79 out o f 113 samples (72%), In the 79 cases evaluable by both FC and CG, a co ncordant ploidy status was found in 66 cases (84%) (47 diploid and 19 aneuploid) (P < 0.001, chi-square test), In the 19 concordant aneuploi d tumors a close correlation between the CMN and the DI was found (y = 0.019 x + 0.151; r = 0.860). Concerning the 13 discordant cases, 11 ( 85%) were classified as aneuploid by FC and as diploid by CG, while 2 cases (15%) were CG aneuploid (1 near-diploid and 1 tetraploid) and FC diploid. The current study suggests that FC is a reliable method for the measurement of tumor DNA content of the studied solid tumors, Spec ial attention should be paid to the improvement of DNA histograms qual ity, in order to reduce the difficulties in the detection of near-dipl oid and near-tetraploid cell populations, Multiple sampling should be warranted whenever possible. (C) 1996 Wiley-Liss, Inc.