A study of 24 cases of salivary gland carcinoma with distant metastasis.

Salivary gland carcinoma is a relatively rare disease of the head and neck. Although it frequently presents with distant metastases, few reports have been published on this subject. The present study investigated the prognosis of patients with distant metastases from salivary gland cancer. A total of 24 cases of salivary gland carcinoma with distant metastasis who were initially treated at the Department of Otolaryngology-Head and Neck Surgery of Nara Medical University during a 16-year period from August 2004 to July 2020 were included. The histopathological types included salivary duct carcinoma (8 cases), adenoid cystic carcinoma (6 cases), myoepithelial carcinoma (3 cases), Squamous cell carcinoma (2 cases), adenocarcinoma (2 cases), acinic cell carcinoma (2 cases) and mucoepidermoid carcinoma (1 case). A total of 18 patients had stage IV carcinoma, which represented the majority. Of all patients, ~80% developed distant metastases within 2 years of initial diagnosis. Survival rates after the appearance of distant metastases were 43.5% at 5 years and 14.5% at 10 years. The results of the current study revealed that no factors significantly influenced long-term prognosis after the development of distant metastases. In future, it may be necessary to re-examine these results in a larger sample size and standardise treatment methods as a result.