[The prognostic significance of cathepsin D in primary breast cancer].

The prognostic significance of the lysosomal protease cathepsin D in breast cancer was evaluated in a retrospective study. Cathepsin D was measured in 346 deep-frozen (-70 degrees C) cytosol specimens of primary breast carcinomas (1982-1990). Among the established prognostic factors, only axillary lymph node involvement correlated with the expression of cathepsin D (> 40/60 pmol/mg) (p = 0.04-0.05). Univariate analyses of disease-free survival (DFS) and overall survival (OS) showed, that the expression of cathepsin D had no effect on the prognosis either in the whole population of breast cancer patients during long-term follow-up (n = 302; median observation time 51 months) or in the group of women with positive lymph nodes (n = 157; 46 months). However, within the group of N0 patients (n = 145; 57 months), high cathepsin D levels were associated with an unfavourable OS, but this relationship was statistically insignificant (p = 0.08-0.13). A similar influence of cathepsin D on DFS could not be demonstrated. Compared to tumour size, grading and receptor status in multivariate analysis, cathepsin D was a more indicative, but finally insignificant prognostic factor for OS. According to these results, cathepsin D may contribute only in combination with other prognostic factors to identify those 20-30% of node-negative patients with unfavourable prognosis, who may benefit from adjuvant therapy.