P(185/HER2) AND PS2 PROTEIN OVEREXPRESSION IN BREAST-CANCER SPECIMENS - IMPROVEMENT FOR PREDICTION OF RESPONSE TO ENDOCRINE THERAPY

Abstract

Simultaneous analyses of p(185/Her2) and pS2 protein expression in breast cancer is discussed to add information about prognosis and response to endocrine treatment. In a retrospective study, expression of p(185/Her2) and pS2 protein were detected by immunohistochemistry in paraffinembedded, formalin-fixed sections of 219 primary breast cancers. Median age was 56.6 years, median follow-up 168 months. Results were correlated with clinical parameters and steroid receptor status. ER was positive in 55%, PgR in 54% of the tumors. ER correlated inversely with tumor size, and with tumor grade. pS2 was detected in 54% of the tumors, but showed no correlations with other parameters. p(185/Her2) was present in 24% of the tumors and correlated positively with tumor size. pS2 and ER or PgR status correlated (p<0.001). In the sub-group of negative steroid receptors and positive pS2 a qualitative significant difference for p(185/Her2) expression was seen. ER, pS2 and p(185/Her2) status had no prognostic impact on disease-free or overall survival; PgR status correlated with clinical outcome.