C-Kit and Bcl-2 Expression in Testicular Cancer

Alterations of C-Kit and Bcl-2 have been shown to play important roles in many types of human cancers. Although there are emerging studies of C-Kit in testicular cancer biology, the significance of Bcl-2 in testicular neoplasms has not been well understood. We studied C-Kit and Bcl-2 expressions by immunohistochemistry in 18 testicular cancers including 8 seminomas, 7 mixed germ cell tumors, 1 metastatic adenocarcinoma, 1 leiomyosarcoma and 1 large cell lymphoma. We found that C-Kit was diffusely and strongly expressed in seminomas and metastatic adenocarcinoma, while only focal weak to moderate C-Kit positivity was shown in seminomatous and nonseminomatous components of mixed germ cell tumor. Bcl-2 expression was seen in metastatic adenocarcinoma and lymphoma with focal weak reactivity in leiomyosarcoma, but not in seminoma and mixed germ cell tumors. Our findings may be helpful in differential diagnosis primary and metastatic testicular cancer and in targeted therapy.