Abstract

HER-2 /neu is a 185-kDa glycoprotein and a transmembrane receptor with tyrosine kinase activity. Its overexpression is observed in 25–30% of primary breast carcinomas and is associated with a poor clinical prognosis. Recently, the U.S. Food and Drug Administration and the Japanese Ministry of Health, Welfare, and Labor approved the use of trastuzumab (Herceptin, Genentech, South San Francisco, CA) for the treatment of patients with metastatic breast carcinomas overexpressing HER-2 /neu. Results of clinical trials with Herceptin suggest that it may prolong the survival of patients with advanced metastatic breast carcinoma. Relatively little is known concerning the relationship between HER-2 /neu status and ovarian clear cell carcinoma. If HER-2 /neu overexpression status were demonstrable in ovarian clear cell carcinoma and a clinical correlation between overexpression and prognosis could be established, a rationale for clinical use of Herceptin for this tumor could be established. Our aim was to evaluate HER-2 /neu status in ovarian clear cell carcinomas. Fifteen ovarian clear cell carcinoma cases were immunostained for HER-2 /neu using HercepTest (DAKO, Glostrup, Denmark). Overexpression of HER-2 /neu was detected in only one case. Unlike in breast carcinoma, HER-2 /neu overexpression appeared to be uncommon in ovarian clear cell carcinomas. Herceptin may thus target only a small proportion of ovarian clear cell carcinomas and be of limited clinical value for treatment of this carcinoma.