Distant metastasis of parotid gland tumors

The incidence of distant metastasis in head and neck cancer and especially in salivary gland cancer is relatively low in comparison to other malignancies. However, the presence of distant metastasis heralds a poor prognosis in head and neck cancer, with a median survival of 4.3–7.3 months. Treatment of these patients is usually performed in a palliative setting. Patients with malignant salivary gland tumors should have an X-ray or CT scan of the chest at their initial assessment to exclude the possibility of distant metastasis. The likelihood of developing distant metastasis is associated with high-grade tumors, such as adenoid cystic carcinoma, salivary duct carcinoma, high-grade mucoepidermoid carcinoma and tumors located in the submandibular gland, posterior tongue and pharyngeal tumors. A lower risk of developing distant metastasis is known for all other histological entities of salivary gland tumors. Nevertheless all patients who have a histologically confirmed malignant salivary gland tumor should h...