IMMUNOCYTOCHEMICAL DETECTION OF DNA TOPOISOMERASE TYPE-II IN PRIMARY BREAST CARCINOMAS - CORRELATION WITH CLINICOPATHOLOGICAL FEATURES

DNA topoisomerase type II (DT-II) is a major component of interphase n uclear matrix fractions, present in S-phase of the cell cycle. A serie s of 80 carcinomatous breast surgical samples was evaluated by immunoh istochemistry, using a polyclonal antibody in a comparison with Ki-67 antiserum. A correlation with clinico-pathological data was also perfo rmed. Infiltrating ductal and lobular carcinomas constantly express DT -II with varying intensity of nuclear staining; a similar immunohistoc hemical pattern is observed with Ki-67. A frequent co-expression of DT -II and Ki-67 is encountered with double immunostaining; accordingly t o these data, a linear relationship is evident when linear regression is employed. In addition, significant relationships between DT-II valu es and tumour size, histological grade and node involvement are shown, while an inverse correlation is appreciable between DT-II and oestrog en receptors and progesterone receptors. DT-II may be considered to be an additional operational marker for the proliferating fraction of ce lls in breast carcinomas.