Management of salivary gland malignancies: current and developing therapies

Abstract

Salivary gland tumors are rare, clinically diverse neoplasms that represent less than 1% of all malignancies. In locoregional recurrent or metastatic disease, systemic therapy is the standard approach. While numerous small phase II studies have evaluated the activity of cytotoxic agents, either alone or in combination, the response rates are generally modest with objective response rates ranging from 15%-50%. Duration of response is cited in the range of 6-9 months. Given this, further evaluation of novel therapies is mandatory in these diseases. With the emergence of molecular targeted therapy, these tumors become optimal candidates for trials of investigational drugs and established drugs for new indications. Of note, given the often indolent nature of disease, only patients with progressive disease should be enrolled and treated on these clinical trials. Study designs must incorporate stringent inclusion criteria to enable accurate reporting of disease response and stabilization. With dedication and co-operation, patients with these rare neoplasms can be accrued to clinical trials and the establishment of new treatment guidelines will be forthcoming.

Review of Salivary Gland Neoplasms

“…However, if we look at each salivary gland in turn, several large series have shown that mucoepidermoid carcinoma is only the commonest cancer in the parotid glands, comprising around 33% [14, 15]. Adenoid cystic carcinoma is the commonest cancer in the submandibular and minor salivary glands, making up 42–49% [14, 15]. A review of 45 parotid cancer patients treated at the author's institute from 2000 to 2010 also shows mucoepidermoid carcinoma to be the commonest type (Table 1).…”

A Case of Sebaceous Carcinoma of the Submandibular Gland

“…Acinic cell carcinoma is also considered to be a low-grade tumour which seldom invades the facial nerve. Regional recurrences occur late in this tumour but 16-20% of patients eventually die of this cancer [14].…”

“…However, if we look at each salivary gland in turn, several large series have shown that mucoepidermoid carcinoma is only the commonest cancer in the parotid glands, comprising around 33% [14,15]. Adenoid cystic carcinoma is the commonest cancer in the submandibular and minor salivary glands, making up 42-49% [14,15].…”

“…Several studies have identified important prognostic factors (Table 2) and postoperative radiotherapy is recommended [14,33].…”

“…More recently, targeted therapies have also been studied, and the targets include epidermal growth factor receptor (EGFR), HER2 protooncogene, c-kit protooncogene, and vascular endothelial growth factor (VEGF). Thus far, no target therapy agent has been found to be effective [14].…”