[Clonal proliferation index and its changes in malignant transformation of tissues].

The microspectrometric investigation used 5- and 8 microns-thick histological specimens, stained after Feulgen, and the following equipment: scanning integrating microspectrophotometer (1,080); TV-image analyzer (70). Interphase nuclei of normal growth tissue, mild and moderate dysplasia, atypical proliferation and carcinoma were investigated using bioptical material from the larynx, cervix uteri, endometrium, stomach, large bowel, prostate and breast. The weighted mean index of DNA accumulation in nuclei as well as the "index of clonal proliferation" (ICP)--ratio of average DNA index for carcinogenesis stage in question and normal tissue index--suggested by the author, were measured. Malignant transformation was characterized by the following ICP values: mild and moderate dysplasia--less than 1.4; intraepithelial neoplasia--2.2 and carcinoma and adenocarcinoma--3.3 and higher. Microspectrophotometric analysis of Feulgen-DNA yields reliable data on ICP in malignant tissue which can be used for clinical purposes in treatment and prognosis of malignant disease.