RELATION BETWEEN CATHEPSIN-D EXPRESSION AND OTHER PROGNOSTIC FACTORS IN BREAST CARCINOMAS

We evaluated cathepsin D concentrations in 318 breast carcinoma specim ens with a standardized IRMA and established distribution values of 5. 9-217.8 nmol/g (median 51.8). Concentrations of cathepsin D did not co rrelate with age or with concentrations of HER-2/neu oncoprotein, estr ogen receptor, or epidermal growth factor receptors, A significant cor relation was observed between cathepsin D and progestin receptor (P = 0.009), but only in postmenopausal patients. In our role as a National Reference Laboratory for conducting interlaboratory comparisons of tu mor markers, we evaluated cathepsin D assay proficiency by using contr ol samples with intra- and interassay CVs of 2-8% and 10-13%, respecti vely. Human reference specimens containing known quantities of catheps in D were developed to facilitate standardized testing. The IRMA proce dure and the use of quality-assurance samples permits evaluation of th e clinical significance of cathepsin D in human breast cancer trials.