Quantitative DNA patterns in human preneoplastic breast lesions.

In 12 cases of human mammary carcinoma in which a preneoplastic atypical ductal hyperplasia was also identified, quantitative DNA (QDNA) measurements of thionein-stained samples from both lesions were performed using the Cell Image Analysis 100 system. The QDNA values in the preneoplastic and neoplastic lesions from each case showed concordance (six as euploid and six as aneuploid/hyperdiploid). Such congruence suggests a stable inheritance of the somatic mutation(s) that is involved in carcinogenesis and that affects ploidy. If this relationship between concurrent preneoplasia and neoplasia in the ipsilateral breast is confirmed, it offers the possibilities of (1) identifying individuals at risk for developing neoplasias with defined biologic characteristics and (2) developing therapeutic regimens more appropriate to the risk assessment of each patient. It may be possible to conceive of a rational preventive regimen for cancer of the breast.