Tissue polypeptide antigen in breast cancer cytosol: a new effective prognostic indicator

Since 1982 we have been evaluating oestrogen and progesterone receptors (PgR), cathepsin D and the cytosolic levels of the tumour marker, tissue polypeptide antigen (TPA), in 257 patients radically resected for breast cancer (follow-up 24-81 months). TPA was measured by an immunoradiometric assay previously validated for cytosol. No significant associations were found between cytosolic TPA and age, tumour size, lymph-node status, receptor status and cathepsin D. TPA+ cases showed a significantly longer disease-free survival (DFS) and overall survival (OS) than TPA-patients (log-rank P < 0.0001). The prognostic value of cytosolic TPA was also demonstrated after stratification by nodal status, PgR and cathepsin D. The prognostic value of TPA was independent of the other prognostic indicators, being the most powerful among the evaluated indices (Cox multivariate analysis: chi 2 15.5 for DFS, 11.4 for OS). We conclude that cytosolic TPA is a powerful additional prognostic factor in primary breast cancer. Its prognostic role should therefore be extensively evaluated.