Efficacy of sorafenib, a multi-tyrosine kinase inhibitor, in an adenoid cystic carcinoma metastatic to the lung: case report and review of literature

Treatment for squamous cell carcinoma of the head and neck has significantly improved with the addition of cetuximab, a monoclonal antibody against the epidermal growth factor receptor, to conventional cytotoxic agents. The most significant aspect of this treatment approach is the proof that head and neck cancers are suitable for targeted therapies as has been shown in other malignancies. Unfortunately, there are other rare histologic types of head and neck cancer such as adenocarcinoma and adenoid cystic carcinoma. The latter has traditionally been considered to be chemotherapy resistant and surgical resection with or without adjuvant radiation therapy has been the rule as far as treatment is concerned. The course of adenoid cystic carcinoma ranges from indolent to aggressive; however, most patients succumb to the disease as a result of distant metastases. This clinical scenario poses a challenge to oncologists. Several conventional chemotherapy regimens and novel targeted agents have been tried in this rare histologic subtype without success.

In this case report, we present a 59-year-old Caucasian female with refractory adenoid cystic carcinoma of the maxilla metastatic to the lung that responded to sorafenib, a novel multi-tyrosine kinase inhibitor, which targets angiogenesis, Raf kinase pathway, platelet-derived growth factor Ret, and c-Kit.

This case illustrates the possibility that this chemoresistant tumor may need the inhibition or blocking of several oncogenic pathways. Certainly, it is imperative that more studies are done in this special population trying to identify tumorigenesis mechanisms that may be upregulated in this malignancy and could be potential targets for therapeutic development.