Imatinib mesylate as treatment for adenoid cystic carcinoma of the salivary glands: report of two successfully treated cases.

Background: Adenoid cystic carcinoma (ACC) is a malignant neoplasia of the salivary glands that is treated primarily by surgery. Local control and survival are usually compromised despite surgery. Expression of KIT tyrosine kinase is involved in the pathogenesis of ACC. Imatinib mesylate is a potent inhibitor of KIT tyrosine kinase, so we explored the possibility that ACC could be a potential target for this drug.

Methods: We report two cases of unresectable ACC treated with imatinib mesylate in the context of recurrent disease (case 1) and locally advanced tumor at its initial presentation (case 2).

Results: Both patients responded well to treatment with imatinib mesylate. Significant regression of recurrent disease (case 1) resulted in a successful salvage surgical resection; the locally advanced tumor (case 2) had an excellent response to treatment, but, unfortunately, the patient refused salvage resection.

Conclusion: This is the first time ACC is reported to respond to imatinib mesylate. Studies in which more patients are enrolled in controlled clinical trials are needed to confirm this observation.