C-kit expression in uterine leiomyosarcomas: an immunocytochemical study of 29 cases of malignant smooth muscle tumors of the uterus.

Uterine malignant stromal tumors are rare neoplasms characterized by fatal prognosis. At the moment no effective systemic treatment is available for metastases or recurrent disease. The drugs employed in advanced neoplasms are iposfamide, doxorubicin or epidoxorubicin, but the clinical response to chemotherapy is poor. Recent studies have shown that cells in gastrointestinal stromal tumors express a growth factor receptor with tyrosine kinase activity termed c-kit. Lately reports of efficacy of a specific anticancer drug with imatinib (ST1571) based on specific molecular abnormalities of proto-oncogene c-kit present in gastrointestinal stromal tumors induced us to identify the c-kit phenotype also in uterine leiomyosarcomas. These data may be useful for treating metastatic uterine leiomyosarcomas with increased c-kit kinase activity.