DNA changes in progressive cervical intraepithelial neoplasia.

Cervical intra-epithelial neoplasm (CIN) is treated as a progressive lesion, even though most CIN will not progress to invasive cancer if left untreated. This study focussed on DNA-cytometric analysis of cytologic smears of patients who had developed invasive cancer after initial smears showing CIN. The first part of the study aimed at describing the DNA-cytometric changes in these progressive ('malignant') CIN lesions. In the second part a cluster analysis was performed on 'malignant' CIN III lesions and CIN III lesions, with 'unknown' malignant potential. The results indicated that 'malignant' CIN lesions developed high DNA-index (DI) values during malignant transformation, as demonstrated by increasing mean DI values, a high percentage of DNA-aneuploidy and 2.5c Exceeding Rates. Furthermore, a trend-like pattern of texture feature values occurred in 'malignant' CIN lesions with increasing severity. These findings provide objective quantitative confirmation of the evolution of nuclear changes during malignant transformation. Cluster analysis showed that it was possible, using a set of four cytometric features, to subdivide the 'unknown' CIN III lesions into a cluster of lesions with feature values similar to the vast majority of the 'malignant' CIN III lesions, and a second cluster of lesions with feature values dissimilar to 'malignant' CIN III. It is argued that the profile of 'malignant' CIN has become clearer and that the results of this study may serve as a basis for a more objective cytopathologic subdivision of premalignant CIN. It may be justified to follow up patients whose lesions do not yet fit this 'malignant' profile. Not treating the non-progressive lesion group will avoid putting these patients at risk.