Cathepsin D concentration in breast cancer cytosols: correlation with disease-free interval and overall survival.

Cathepsin D (CD) is an aspartyl protease implicated in cancer metastasis. In this study of 331 patients, we show that patients with primary breast carcinomas containing high concentrations of CD have a significantly shorter disease-free interval (chi-square = 4.28, P < 0.05) and overall survival (chi-square = 7.7, P < 0.01) than patients with low concentrations. CD as a prognostic marker for overall survival was equally valuable for women younger (chi-square = 4.39, P < 0.05) and older (chi-square = 3.97, P < 0.05) than 50 years. CD was also a significant prognostic marker for overall survival within the estradiol receptor (ER)-positive subgroup of patients (chi-square = 5.79, P < 0.025), but not in the ER-negative subgroup. Patients with tumors containing high concentrations of CD and low concentrations of ER had shorter disease-free intervals (chi-square = 15.1, P < 0.001) and lower overall survival (chi-square = 20.9, P < 0.001) than patients with high concentrations of ER but low concentrations of CD.