Systemic therapies for recurrent and/or metastatic salivary gland cancers.

Salivary gland carcinomas are rare cancers, comprising 1-5% of head and neck cancers. They represent a morphologically and clinically diverse group of tumors. The most commonly histopathologic types are mucoepidermoid cancer, adenoid cystic cancer and adenocarcinomas. Malignant salivary gland tumors generally present as painless, slow-growing tumors that are indistinguishable from benign tumors. Surgery is the principal treatment and is curative in early stage. Radiation therapy should be considered in most patients after surgical resection. Chemotherapy is reserved for palliative treatment of metastatic disease but results are disappointing. Recent studies have investigated the role of targeted therapies in a palliative setting. Multicentre cooperative group clinical trials are required to assess novel therapies to maximize patient resources in this uncommon tumor.