DISCREPANCIES OF DNA CONTENT OF VARIOUS SOLID TUMORS BEFORE AND AFTERCULTURE MEASURED BY IMAGE-ANALYSIS - COMPARISON OF CYTOGENETICAL DATA

Parallel cytophotometric ploidy studies and cytogenetic analysis were performed on 15 various human solid tumours. The quantification of DNA by image analysis was carried out on cytological imprints of fresh tu mours and on smears obtained after cell culture. The results obtained by both sets of calculations were compared with each other and with th e cytogenetic results. 6 cases (40%) showed concordance between the 3 techniques. One case was aneuploid for both DNA image analysis measure ments but the cytogenetic data showed only a diploid stem line. In 3 c ases out of 15 (20%), smears DNA analysis and cytogenetic results were concordant: in 2 tumours, the culture step failed to preserve aneuplo id stem lines that were present in the imprint analysis. In the third one, a minority tetraploid peak observed after culture was absent on t he imprint slide. Concordance between imprints and cytogenetic data an d discordance with smears' analysis was observed in 3 cases (20%). The se 3 cases were diploid or near diploid but the DNA analysis on the sm ears after culture showed an aneuploid stem line in each case. The las t 2 cases showed a total disagreement between the 3 techniques. By mea suring the DNA content with an image analyser, the observer can ensure that only tumoral cells are taken into account. The present study rev ealed that cytogenetic data represent only about 60% of the population that is effectively present in the culture dish and that the cultured population represents only 47% of the population present on the fresh tumour imprint.