c-erbB-2 protein expression in node negative breast cancer.

We investigated the expression of c-erB-2 protein in two matched groups of breast cancer patients, one with and one without relapse. 37 patients with relapse were compared with 42 patients without recurrence for time of observation, adjuvant treatment, age, menopausal status and estrogen receptor content. Paraffin-embedded sections were stained with the polyclonal antibody 21N, raised against a synthetic peptide from the predicted sequence of the c-erbB-2 protein. The staining of c-erbB-2 was measured on a scale of 0 to 3+. C-erbB-2 staining was negative in 16 (38%) patients in the relapse-free group, and in 8 (22%) of the patients with metastases. Neither disease-free survival (DFS) nor overall survival (OS) were dependent upon the extent of c-erbB-2 expression. An analysis by estrogen receptor (ER) status (i.e. positive or negative) and by c-erbB-2 expression (i.e. positive or negative) revealed that patients with ER-positive primaries and negative c-erbB-2 have the longest disease-free survival (DFS) and overall survival (OS). We conclude that c-erbB-2 expression might be clinically useful only if other prognostic variables (e.g. estrogen receptor content in the tumor) are also considered.