IMMUNOHISTOCHEMICAL DETECTION OF CATHEPSIN-D IN T(2)N(0)M(0) BREAST-CARCINOMA

Recent studies have reported significant but inconsistent correlations between tumor cathepsin D (CD) concentration and prognosis in breast carcinoma. To investigate the tissue distribution and a prognostic uti lity of CD in breast carcinoma, 159 cases of T(2)N(0)M(0) breast carci noma with a minimum of 10 years' follow-up were studied for CD express ion by immunohistochemistry. This group of patients was chosen for stu dy because of current interest in prognostic markers for stage I breas t carcinoma and the likelihood that there would be sufficient recurren ces in this group to detect significant differences. Seventy-two carci nomas (45%) showed prominent staining of cells composing the tumor. Ne oplastic cell staining for CD correlated with well-differentiated arch itecture, and lack of neoplastic cell CD expression correlated with hi gh nuclear grade and the medullary carcinoma category. Stromal cell (p rimarily histiocyte) staining in carcinomas was the major contributor to CD expression in 67 of the 159 cases (42%). Intense intratumoral st romal cell staining correlated with absence of estrogen receptors and the medullary carcinoma subtype. There was no significant correlation between disease-free or overall survival and (a) intensity of overall staining for CD, (b) staining of carcinoma cells alone, or (c) stainin g of nonneoplastic cells within the region of the carcinoma. These res ults show that a significant proportion of CD activity detected within a tumor by immunohistochemistry may be contributed by nonneoplastic c ells, and there is no significant correlation between survival and imm unohistochemical detection of CD in T(2)N(0)M(0) breast cancer.