Immunoradiometric assay of cathepsin D: Estrogen regulated vs. non estrogen- regulated cathepsin D expression in relation to clinicopathological features of breast cancer

Background: Cellular biomarkers may predict tumor cell behavior in breast cancer. One of the most paradoxical biomarker in breast cancer is cathepsin D. Patients and methods: The study includes 152 patients with histologically verified breast carcinoma. Clinicopathological findings were classified according to classical breast carcinoma-host features (age and menopausal status) and carcinoma features (lymph node status, tumor size type and grade). Estrogen and progesterone receptors were assayed in accordance with the recommendation of the EORTC. Cathepsin D concentrations were determined using immunoradiometric assay. The results were analyzed using non-parametric statistical methods. Results: All differences in the proportion of breast carcinoma classified as cathepsin D-positive and disagreements on the association of cathepsin D status with clinicopathological features of breast cancer are the result of varying cut-off values used by different authors. Using the cut-off value, which defines estrogen-regulated vs. nonestrogen-regulated cathepsin D expres sion, this study points to the cathepsin D status as a complementary biolog ical information to ER and PR status, and a dependent biomarker in relation to age of patients and lymph node status. Conclusion: The classification of tumors according to the cathepsin D status within ER and PR status could provide more information on the association between cathepsin D status and clinical-pathological features of breast cancer