Telomerase activity levels for evaluating the surgical margin in breast-conserving surgery

To evaluate the efficiency of measuring telomerase activity levels in clini cal diagnosis, we per formed a semiquantitative analysis of telomerase acti vity in breast tumors and compared the results with the histological findin gs. Breast tissue adjacent to areas of cancer were also serially resected a nd checked for telomerase activity. The amount of telomerase activity in th e breast cancers ranged widely, from 0.36 to 1180 units/mug, with 31 of the 34 (91.2%) showing a value above 1.0 unit/mug. None of the normal breast t issues including mastopathy, and only 4 (23.5%) of 17 benign breast masses had values above 1.0 unit/mug. Telomerase activity was detectable in serial sections of adjacent tissues as far as 10 mm from the macroscopic tumor ma rgin with histologically detectable cancer cells. Furthermore, telomerase a ctivity was detectable in the scrape specimens obtained from the stump of t he surgical margins for breast-conserving surgery, and this activity was in accordance with the histological findings. These findings show that conduc ting a semiquantitative assay of telomerase activity is useful for evaluati ng the surgical margin in breast-conserving surgery.