P53 and cathepsin-d are independent of established prognostic factors in breast-cancer.

p53 and cathepsin D expression was investigated in 300 primary breast cancers by the avidin-biotin immunoperoxidase method using two murine monoclonal antibodies: PAb1801 and anti-procathepsin D, respectively. The frequency of p53- and cathepsin D-positive cells varied widely among different tumors and most tumors (82% and 86%) at least occasionally showed positive cells. The two biological markers were unrelated to one another, to cell proliferative rate and ploidy and were differently related to other biological and pathological features. In particular, p53 was directly related to tumor size and nodal involvement and inversely related to the presence of steroid receptors. Conversely, cathepsin D was directly related only to nodal involvement.