The diagnostic significance of flow cytometric nuclear DNA measurement in gastroscopic diagnosis of the stomach.

Cell material obtained from 161 patients by gastroscopic aided brushing was compared cytologically and DNA flow cytometrically and evaluated by mathematical discriminant analysis. Whereas all but one of the cytologically confirmed malignant cases were also positive (malignant) in flow cytometry, the DNA determination failed in 6 of the 19 cytologically suspicious cases, having been classified as negative (benign) by cytometry. Out of all cytologically unequivocal malignant and suspected cases, 18% (7 cases) were false-negative in flow cytometry. The false-positive rate was 39% (47 cases). 5% of the material was classified as inadequate for diagnosis (8 cases) by flow cytometry. The false-negative rate of flow analysis in cytologically suspicious cases is apparently caused by a less pronounced increase of DNA content in the cell nuclei of these cases. Reactive gastric mucosa alterations such a inflammations, erosions or ulcers exhibited increased cell nuclear DNA. According to these results, DNA determination can be used as an automated diagnostic procedure for tumour detection only in combination with other measuring criteria.