LACK OF PROGNOSTIC VALUE OF CATHEPSIN-D LEVELS FOR PREDICTING SHORT-TERM OUTCOMES OF BREAST-CANCER PATIENTS

The value of cathepsin D determinations done on tumor cytosols in eval uating the prognosis of breast cancer patients has been debated in the literature. Our previous work suggested that cathepsin D determinatio ns were not of prognostic value, but in that study we used immunoblott ing and immunohistochemical methods rather than the more widely used d ouble antibody immunoradiometric (IRMA) assay for measuring cathepsin levels. Here we report our results determining cathepsin D using compo nents of a commercially available IRMA system on a large patient sampl e (n = 1984). Reagents from a commercially available IRMA kit were use d to analyze cathepsin D levels in the cytosols of 1984 patients with breast cancer. All patients had invasive breast cancer with known tumo r size and with some axillary nodes pathologically examined. Only pati ents with T1 and T2 tumor sizes were included, Median follow-up was 37 months. The hypothesis that high cathepsin D levels correlated with p oorer outcome (poorer DFS or OS) was not confirmed, either in all pati ents, or in node-positive or node negative subsets. Only in patients t reated with adjuvant therapy were higher cathepsin D levels correlated with negative outcome (worsened OS, but not DFS), although given the large number of subsets analyzed this correlation may be spurious. Mul tivariate analyses using interaction terms did not support the concept that high cathepsin D levels correlate with resistance to adjuvant th erapy. In this study evaluating the value of cathepsin D using compone nts from a kit widely used for measuring cathepsin D levels, we conclu de that cathepsin D is of doubtful value in predicting risk of early r elapse or death for patients with newly diagnosed invasive breast canc er. Published by Elsevier Science Ireland Ltd.