Purpose: The aim of the present study was to investigate the possibility of treating uterine sarcomas with imatinib mesylate. Imatinib mesylate, a selective tyrosine kinase inhibitor, is very efficient against mesenchymal tumors of the gastrointestinal tract, known as GISTs. Imatinib mesylate acts against a tyrosine kinase encoded by the KIT gene in GISTs, and is more effective in tumors expressing this protein.
Methods: Expression of KIT was analyzed immunohistochemically (n = 12) in formalin-fixed paraffin-embedded primary uterine sarcomas.
Results: Using a semi-quantitative immunohistochemical score we found that KIT expression was very weak in the majority of tumors, while none of the uterine sarcomas tested showed strong expression. Overall, published studies addressing this issue in small series of uterine sarcomas yielded similar results.
Conclusion: Current data suggest that it is unlikely that imatinib mesylate could be used effectively as a single agent in patients with uterine sarcomas.