DNA-FINGERPRINTING OF BENIGN AND MALIGNANT BREAST-LESIONS

Paired blood and breast tissue samples from 96 patients undergoing sur gical excision of a breast lesion were subjected to DNA fingerprint an alysis using the minisatellite probes 33.6 and 33.15, The 'fingerprint s' of the blood and breast DNA were compared, DNA fingerprint changes seen were classified as band additions, band deletions or changes in b and intensity, Significantly more DNA fingerprint changes mere seen in malignant than in benign lesions (probe 33.6, P<0,01; probe 33.15, P= 0.01; both probes, P=0.04), The frequency of the changes detected in t he breast cancers was unrelated to tumour grade or the presence of inv asion, DNA ploidy was measured in 70 of the breast carcinomas, DNA fin gerprint changes mere seen in 41 of these, but flow cytometry detected aneuploidy in only 29 tumours (P=0.04), The DNA fingerprinting techni que is unlikely to be useful in differentiating between benign and mal ignant breast lesions as changes were detected in one of the fibroaden omas studied, However, it may be a useful technique in screening tumou r DNA for abnormalities suitable for more detailed analysis.