CATHEPSIN-D, BOTH A PROGNOSTIC FACTOR AND A PREDICTIVE FACTOR FOR THEEFFECT OF ADJUVANT TAMOXIFEN IN BREAST-CANCER

Cathepsin D is a lysosomal protease implicated in cancer metastasis. I ts concentration in breast tumours has also been shown to be of progno stic importance, although to what extent this is subject to lymph node status, the use of adjuvant therapy and menopausal status has not bee n clearly evaluated. At a cut-off level of 45 pmol/mg protein (61% of the 623 samples were classified as high cathepsin D tumours; immunorad iometric assay), we found cathepsin D to be of prognostic importance o nly among breast cancer patients with lymph node-positive (N+) disease not treated with adjuvant tamoxifen. When the series was stratified a ccording to cathepsin D content of their tumours, progesterone recepto r (PgR) status and lymph node involvement, adjuvant tamoxifen was foun d to have a significant beneficial effect only among patients with Nand PgR-positive breast cancer whose tumours had a high cathepsin D co ntent.