pS2 protein detected by immunohistochemistry in archival primary breast cancer.

It has been proposed that pS2 protein in breast cancer provides information on the individual prognosis and biological properties of the tumor with respect to response to endocrine treatment. In this retrospective study the pS2 protein expression was detected by immunohistochemistry in formalin-fixed, paraffin-embedded breast cancer sections from 219 patients with primary breast cancer. The data were compared with patients' age, disease stage and tumor grading tumor estrogen and progesterone receptor status, disease-free interval and overall survival. Documented follow-up of up to 138 months with a mean of 69 months was analysed. 54% of the tumors were pS2-positive. There was a significant positive correlation with steroid receptor content. There was no correlation of pS2 with patient age, staging or grading pS2 could not contribute more prognostic information beyond steroid receptor status or axillary lymph node involvement. Survival analysis of the pS2-positive and negative. tumor patients failed to show a significant difference.