Expression of HER-2/neu in testicular tumors.

BACKGROUND

Although the overexpression of the Epidermal Growth Factor Receptor 2 (EGFR-2, HER-2/neu, c-erbB-2) in malignancies might predict chemoresistance and poor prognosis, its clinical relevance has not been widely studied and determined in testicular tumors.

PATIENTS AND METHODS

Since teratomas are relatively chemoresistant tumors, we evaluated the HER-2/neu receptor status of 28 primary testicular tumors (7 pure teratomas, 21 mixed germ cell tumors containing teratomatous components) using a standardized immunohistochemical method (HercepTest Kit).

RESULTS

Seven (25%) out of 28 non-seminomatous germ cell tumors showed HER-2/neu positivity. The teratomatous components of mixed GCTs showed HER-2/neu overexpression in 5 cases. Three of the 5 choriocarcinoma components of mixed tumors overexpressed HER-2/neu. In one case (teratoma + choriocarcinoma) both components showed HER-2/neu overexpression. No HER-2/neu overexpression was detected in other, less differentiated histological subtypes. Among the HER-2/neu-positive cases, 3 patients are in complete remission, 3 patients are in partial remission and one patient died after primary chemotherapy.

CONCLUSION

Twenty-five percent of the non-seminomatous germ cell tumors which contain teratomatous components overexpress HER-2/neu protein. The overexpression is restricted to the more differentiated histotypes. Further molecular investigations and clinicopathological studies are necessary to determine the correlation between HER-2/neu overexpression and clinical resistance of testicular tumors.