ABSTRACT
Topoisomerase IIalpha (topo IIalpha) is the target enzyme for several antineoplastic drugs. Correlation between low expression of topo IIalpha and drug resistance has been shown in vitro, but there is limited evidence of a correlation to initial response to treatment or to overall prognosis. Normal cells express topo IIalpha in S/G2/M phase of the cell cycle but not in G0/G1 phase. However, some data suggest that topo IIalpha could be expressed in G0/G1 phase in malignant cells. We have investigated the expression of topo IIalpha in leukemic cells from 25 patients with acute leukemia by flow cytometry, separating cells of different cell cycle phases. We demonstrated that 9/25 samples showed >50% positive cells in G0/G1, and another five samples showed >20%. This finding could possibly provide an explanation to previous difficulties in correlating topo IIalpha expression with clinical outcome. Six of eight patients, where >20% of the cells in G0/G1 were positive for topo IIalpha, entered CR, compared to one of five patients with <20% topo IIalpha positive cells in G0/G1. We suggest that topo IIalpha expression in G0/G1 in leukemic cells may be of predictive value for clinical response to cytostatic drugs.
Subject(s)
Cell Cycle , DNA Topoisomerases, Type II/metabolism , Leukemia/pathology , Acute Disease , Adult , Aged , Aged, 80 and over , Antigens, Neoplasm , Case-Control Studies , DNA-Binding Proteins , Flow Cytometry , G1 Phase , Humans , Leukemia/diagnosis , Leukemia/enzymology , Middle Aged , Prognosis , Remission Induction , Resting Phase, Cell Cycle , Treatment OutcomeSubject(s)
Ethics, Medical , Patient Advocacy , Physician's Role , Prisoners , Prisons , Humans , SwedenABSTRACT
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.
Subject(s)
Breast Neoplasms/genetics , Clinical Laboratory Techniques , DNA, Neoplasm/analysis , Flow Cytometry , Ploidies , Cryopreservation , Humans , Prognosis , Reproducibility of Results , S Phase/geneticsABSTRACT
In order to study interinstitutional reproducibility of flow cytometric DNA-analysis (DNA-FCM), frozen pieces from 30 consecutive breast carcinomas were analysed by 5 laboratories. Different instruments, preparation and DNA staining methods were used. A concordance in DNA-ploidy status was obtained in 26 of the 30 tumours. The discrepancy can mainly be explained by intratumoural DNA-heterogeneity since a complete agreement in ploidy status was obtained when four of the laboratories analysed the same cell suspension, where solid bits showed differing results. The sampling method seems therefore to be a crucial step for the results and needs further studies. As far as the estimation of S-phase fraction was concerned, one laboratory obtained significantly higher values compared to the other four. The correlation between the other four laboratories varied between r = 0.66-0.92.
Subject(s)
Breast Neoplasms/genetics , DNA, Neoplasm/analysis , Flow Cytometry/methods , Academies and Institutes/standards , Animals , Humans , Ploidies , Regression Analysis , Reproducibility of Results , S PhaseABSTRACT
Immediate breast reconstruction after mastectomy can be performed safely with a low incidence of complications. There is no evidence that reconstruction with a submuscular implant interferes with subsequent oncologic care, followup, or outcome for patients.
