Cathepsin D may help in discriminating node-negative breast cancer patients at risk for local-regional recurrence

The objective of this retrospective study was to define the prognostic value of cathepsin D (CD) in the node-negative (N-) and node-positive (N+) subsets of breast cancer (BC) patients.

In primary tumor cytosols of 348, stage I-III, BC patients, with a complete standard histological examination and a 56 months mean follow-up, the ER, PR and CD concentrations were measured by standardized assays. CD values were then compared to the classical prognostic factors, the type of treatment and the outcome, in terms of Disease-Free-Survival (DFS) and type of Relapse, after stratification according to the nodal status. Statistical methods used were Cox regression and logistic regression.

Using univariate analysis, CD > 60 pmol/mg prot in N- patients was significantly associated with shorter DFS as well as local-regional recurrence (LRR) while in multivariate analysis the same CD levels, together with T status, are the best predictors of short DFS. However, CD > 60 is the only potent predictor of LRR in N- patients. No prognostic value of CD was identified in N+ patients. The cutoff value of CD should be 60 pmol/mgprot. The combination of tumor size, ER status and CD concentration may yield reliable prediction of primary BC outcome in N- patients.

CD is a marker of invasiveness, particularly loco-regional in node-negative breast cancer. The integration of this marker, in the routine of initial prognostic evaluation of this subset of patients is proposed.