Background: Primary salivary gland type nasopharyngeal carcinoma (SNPC) is a rare malignancy with diverse clinical behavior and different prognoses. Previous studies have reported on limited patient populations, and few long-term studies have outlined outcomes and prognostic factors. Furthermore, controversy exists as to the treatment policy of SNPC. The aim of this study was to define management approaches, therapeutic outcomes, and prognostic factors of SNPC.
Methods: The medical records of 67 patients with SNPC at 1 institution between 1977 and 2005 were reviewed. Patient records were analyzed for management approaches, outcomes, and prognostic factors.
Results: SNPC is a rare malignancy accounting for only 0.29% of nasopharyngeal malignancies, and the lymphatic metastases and distant metastases rates were 28.4% and 23.9%, respectively. The 5-year disease-free survival (DFS) and overall survival (OS) rates were 41.1% and 57.1%, respectively; no significant differences were found in DFS or OS between different histological subtypes. A significant difference was found in OS between surgical treatment and nonsurgical treatment in T1-T2 patients with well-differentiated tumors. Multivariate analyses indicated that lymph node metastases, stage, and distant metastases were independent factors for DFS, whereas cranial nerve invasion, tumor residue, and distant metastases were independent factors affecting OS.
Conclusions: SNPC is a malignancy with generally favorable prognosis. In T1-T2 patients with well-differentiated tumors, SNPC should be treated by combined surgical operation and radiotherapy. Cranial nerve invasion, tumor residue, and distant metastases were independent factors affecting OS.