Radiotherapy as salvage treatment of salivary duct carcinoma in major salivary glands without radical operations

BACKGROUND: Salivary duct carcinoma (SDC) is an extremely rare and highly malignant carcinoma, and surgical radical resection is the most effective therapy. However, there were quite a proportion of patients receiving non-radical resections, and how to treat them remained controversial. Thus, the aim of this study is to evaluate whether postoperative radiotherapy could be a salvage treatment of SDC in major salivary glands without radical operations. PATIENTS AND METHODS: We identified 40 pathologically diagnosed SDC patients who came to our hospital and did not receive radical operations. Thirty-three patients received at least one treatment (remedial operation, postoperative radiotherapy and chemotherapy), and seven patients only chose observation and received no further treatment. The prognostic indicators of the local–regional control (LRC) and distant disease-free survival were analyzed using the Kaplan–Meier methods and the Cox proportional hazards regression models. RESULTS: Thirteen patients experienced local–regional recurrence or local progression, and distant metastases were observed in 15 patients. Through multivariate analysis, we found that postoperative radiotherapy was associated with better LRC, but this kind of treatment did not show significant efficacy in the prevention of distant metastasis. CONCLUSION: SDC is a rare, aggressive malignancy, and a substantial proportion of these patients experienced inadequate initial treatments. Although postoperative radiotherapy could not decrease distant metastases, it might help to improve LRC in patients with SDC.