CORRELATIONSHIP OF CATHEPSIN D AND TOPOISOMERASE II ALPHA WITH NUCLEAR GRADING IN BREAST CANCERS.

56 cases of infiltrating duct carcinoma of the breast were studied for the expression of cathepsin D and topoisomerase II alpha. The results were correlated with the morphological differentiation, as determined by the Nottingham's modification of the Bloom-Richardson system. Cathepsin D posltivity in tumour cells and stromal cells was seen in 44.6% and 55.4% cases respectively, whereas topoisomerase II alpha positivity was seen in 33.9% cases. In grade II tumours cathepsin D in tumour cells and stromal cells was 44.4% and 47.2% respectively, as compared to 27.8% posltivity for topoisomerase II alpha. The corresponding figures for grade III tumours were 50.0%, 79.6% and 64.3 % respectively. As grade I comprised only 3 cases no statistical correlation could be observed. It is evident that with increase in tumour grade there is a statistical increase in expression of cathepsin D, a lysosomal acidle protease-implicated in the process of tumour invasion and metastasis, and of topoisomerase II alpha, a marker of rapid cell proliferation and aneuploidy.