An evaluation of Feulgen-acriflavine-SO2 and Hoechst 33258 for DNA cytofluorometry in tumour pathology

Receptors for EGF and oestradiol and thymidinekinase activity in different histological subgroups of human mammary carcinomas

The cellular content of receptors for epidermal growth factor (EGF) was measured in different histological subgroups of human mammary carcinomas. EGF receptors were detected in 36% of the ductal and all the medullary carcinomas. In contrast lobular and pure colloid tumours did not contain measurable amounts of the receptor. The receptor was found both among tumours with an euploid and aneuploid DNA pattern. The EGF receptor is thus found in carcinomas with a varying degree of differentiation as judged by the cellular DNA pattern. There was no correlation between the proliferative activity of the tumours as measured by thymidinekinase activity and the amount of EGF receptors in the tumour. Tumours with detectable EGF receptor often had low levels of oestrogen receptor. This finding could only partly be explained by the menstrual status of the patients.

A comparison of static cytofluorometry and flow cytometry for the estimation of ploidy and DNA replication in human breast cancer

332 primary invasive breast carcinomas were analysed by static cytofluorometry and flow cytometry. The ploidy distributions were similar, and 54% of the tumors were judged DNA aneuploid by both methods. The coefficient of variation of the G0-G1 peaks ranged from 2.0 to 8% with both techniques, but the mean was somewhat lower with flow cytometry--4.1%, compared to 4.9% for the static measurements. The proportion of S-phase cells was possible to estimate from 80% of the flow histograms and 70% of the static histograms. S-phase was not estimated from the static histograms if less than 150 tumor cells were measured. With 160 tumors S-phase was measured by both methods. The range was 0 to 27% with the static measurements and 0.7 to 25% with flow cytometry. Corresponding mean values were 7.6% and 8.2%, which are similar to thymidine labeling index results with breast cancers reported in some studies. A close correlation was obtained (r = 0.927) comparing S-phase fractions estimated from aneuploid tumors with flow cytometry and static cytofluorometry if more than 200 cells were measured with the latter. The proportion of S-phase cells was significantly lower for the diploid tumors. We conclude that both techniques can be useful for the estimation of DNA ploidy and replication in human breast cancer.

DNA distribution, cytosol estrogen receptors and axillary nodes as prognostic predictors in breast carcinoma

One hundred and fifty patients with breast carcinoma were examined to compare axillary node status, estrogen receptor level and cellular DNA content as prognostic indicators. Seventy-four per cent of the patients were postmenopausal and forty per cent had axillary node metastases. Estrogen receptor was measured by isoelectric focusing in polyacrylamide gel. DNA was measured in individual cell nuclei by means of Feulgen-acriflavine-sulphate stained imprints. Fifty-two per cent of the tumors had diploid and/or tetraploid DNA pattern, and the rest aneuploid pattern. Axillary node metastases, aneuploid DNA pattern and low level of estrogen receptor were related to recurrence. When introduced into Cox's proportional hazards procedure, axillary nodes and estrogen receptor level but not DNA pattern remained as significant predictors of recurrence.

Rapid yeast DNA staining method for flow cytometry

The variation of the fluorescence intensity of olivomycin-stained yeast cells as a function of the concentration of olivomycin, NaCl, and MgCl2 in the staining solution was studied. The best results were obtained when the staining solution contained 100 micrograms, olivomycin/ml, 40 mM MgCl2, and 1 M NaCl. A staining time of 12 min was sufficient for proper staining.

A fast and reliable system for microcomputerized DNA cytofluorometry in tumour pathology

A microcomputerized cytofluorometry system based on a Leitz MPV 3 cytophotometer, and intended for DNA measurements in tumour pathology is described. The system has been equipped with a reference channel for correction of excitation light instability. The importance of the adjustment of the epi-illumination for optimal performance of the reference channel is stressed, and a detailed description is provided. An apparatus variability well below 1% CV is obtained even during periods of marked instability of the arc-lamp. Software for conventional cytofluorometry with which about 200 cells can be measured in 20 min is presented. In addition a measuring technique where cells are not positioned, but are just passed through the excitation light spot is described. Preliminary results on cytocentrifuged specimens of human cancers indicate that this system is at least three times faster than conventional fluorometry. The increased speed of measurements considerably extends the possibilities to evaluate cell proliferation using static cytofluorometry. The measuring capacity of course is dependent upon the quality of the specimen. In well prepared cytocentrifuged specimens 1000 cells have been measured in 35 min.