IMMUNOHISTOCHEMICAL ASSESSMENT OF CATHEPSIN-D IN STAGE-I AND STAGE-IINODE-NEGATIVE BREAST-CANCER

We studied the distribution of cathepsin D, an estrogen-regulated enzy me with mitogenic and proteolytic activity, on formalin-fixed, paraffi n-embedded tumor sections from 82 patients with node-negative breast c arcinoma by using the avidin-biotin-peroxidase complex method. A rabbi t antihuman cathepsin D polyclonal antiserum was used. Positive staini ng in tumor and stromal cells was independently evaluated and was corr elated with disease-free survival and other clinicopathological parame ters (age, tumor size, nuclear grade, mitotic count, and estrogen rece ptor status). Forty-seven cases (57%) showed distinct granular cytopla smic staining in tumor cells (mean, 25%; range 1-90%) and 48 cases (59 %) showed immunoreactivity in stromal cells. The presence or absence o f staining in tumor and stromal cells was not concordant in all cases. All patients had a minimum of 5-year follow-up. Eighteen patients had tumor recurrence, and neither tumor nor stromal cathepsin D staining was predictive of disease-free survival. None of the other parameters evaluated showed any significant correlation with the cathepsin D stai ning of the tumor or stroma.