Steroid receptors, pS2 and cathepsin D in early clinically node-negative breast cancer

Four oestrogen-regulated proteins of reported prognostic value, oestrogen receptor (ER), progesterone receptor (PR), pS2 and cathepsin D (Cat D), have been quantified by immunoassays, and the latter studied by immunohistochemistry (IHC) in primary tumours from clinically node-negative early breast cancer patients, entered into a trial of breast conservation therapy in which all the patients received adjuvant tamoxifen. ER, PR and pS2 significantly co-correlated but none correlated with Cat D. ER, PR and pS2, but not Cat D, were significantly associated with tumour size and grade, although Cat D tended to show an inverse relationship with the latter. Cat D (radioimmunoassay) in pmol/mg significantly correlated with the IHC score for Cat D in carcinoma cells as well as the number of Cat D-expressing macrophages. At a median follow-up of only 16 months, recurrence was significantly more common in patients with tumours having negative status for ER, PR and pS2 but was not associated with Cat D status.