Serological and Immunohistochemical HER-2/neu Statuses Do Not Correlate and Lack Prognostic Value for Ovarian Cancer Patients.

The serodiagnostics of extracellular domain (ECD) HER-2/neu has turned into an evidenced-based tumour marker for HER-2/neu-positive breast cancer patients. This study investigated the clinical relevance of immunohistochemical and serum HER-2/neu in 44 patients with advanced ovarian cancer. The Hercept-Test® from DAKO Diagnostics was used to analyse immunohistochemical HER-2/neu expression. The HER-2/neu ECD in serum was determined quantitatively by Bayer Immuno 1™ Immunoanalyser. The HER-2/neu serum values were correlated to the clinical course of disease and to established prognostic factors, i.e. progression-free and overall survival. Some 23% of patients (n = 11) expressed HER-2/neu serum levels higher than 15 ng/mL, whereas only 7.7% (n = 2) of the patients examined by immunohistochemistry showed a HER-2/neu overexpression of the tissue. None of them revealed an overexpression of HER-2/neu ECD by serodiagnostics. HER-2/neu overexpression did not correlate significantly to any of the analysed prognostic factors. According to progression-free and overall survival, there was no significant difference between serologically HER-2/neu-positive or negative patients. For ovarian cancer patients, neither high HER-2/neu serum levels, nor immunohistochemically determined HER-2/neu positivity, appear to predict the course of disease. This study shows a lack of association between the immunohistochemical HER-2/neu status and the serum level of solute extracelluar HER-2/neu domain.