Postoperative radiotherapy in patients with salivary duct carcinoma: clinical outcomes and prognostic factors

Abstract

This study sought to investigate the clinical outcome and the role of postoperative radiotherapy for patients with salivary duct carcinoma (SDC) who had undergone surgery and postoperative radiotherapy. We performed a retrospective analysis of 25 SDC patients treated between 1998 and 2011 with surgery and postoperative radiotherapy. The median prescribed dose was 60 Gy (range, 49.5–61.4 Gy). The clinical target volume (CTV) was defined as the tumor bed in four patients, the tumor bed and ipsilateral neck in 14 patients, and the tumor bed and bilateral neck in six patients. Local control (LC), disease-free survival (DFS) and overall survival (OS) were estimated using the Kaplan-Meier method, and prognostic variables were analyzed with the log-rank test. The 5-year LC, DFS and OS were 67%, 45% and 47%, respectively. Disease recurrence was found in 12 patients: seven as local, four as regional and eight as distant failure. Perineural and lymphovascular invasion was a significant prognostic factor for LC (P = 0.03). Local failure was common, and the presence of local recurrence significantly affected the OS (P < 0.05). We conclude that surgery and postoperative radiotherapy is expected to decrease the risk of local failure and contribute to good prognoses for patients with SDC. It might be advisable to have the CTV include the cranial nerves involved and the corresponding parts of the skull base in cases of pathologically positive perineural invasion.

Salivary duct carcinoma treated with cetuximab-based targeted therapy: A case report

“…By contrast, SDC metastases occur earlier and develop more rapidly, suggesting that the efficacy of lung metastasectomy for SDC may be insufficient when compared to its efficacy for ACC. In the case presented herein, SDC developed in the submandibular gland and the patient had lymph node metastases at initial diagnosis, as described previously (2,(7)(8)(9)(10)(11)(12). Radical tumor resection with ipsilateral neck dissection were first performed, followed by lung metastasectomy via VATS for left lower lung metastasis and adjuvant chemotherapy.…”

“…Kleinsasser et al (25). This type of cancer is considered to be among the most aggressive salivary gland carcinomas due to the high frequency of local recurrence, as well as associated cervical lymph node and distant metastases (2,(7)(8)(9)(10)(11)(12). The most common treatment for SDC is surgery, particularly extended radical resection and ipsilateral neck dissection, with postoperative radiotherapy (2,6,7).…”

“…Between 2005 and 2015, SDC patients were frequently diagnosed at an advanced stage, as in 55-82% of the cases the disease had already spread to the cervical lymph nodes on first diagnosis. Furthermore, local and regional recurrence and distant metastasis following surgery and postoperative radiotherapy were observed in 11-48, 8-26 and 24-63% of the patients, respectively, with a 5-year survival rate of 42-55% (2,(7)(8)(9)(10)(11)(12).…”

“…SDC presents as a rapidly growing mass with the potential for local recurrence and cervical and/or distant metastases, and is associated with a high mortality rate. Although surgery, including extended radical resection and ipsilateral neck dissection, followed by postoperative radiation is the standard treatment for SDC (2,6,7), there is currently no standard systemic treatment.…”

“…The overall 5-year survival rate associated with SDC is low (42-55%) (2,(7)(8)(9)(10)(11)(12). Recent studies have tested molecularly targeted therapies as novel treatment strategies for SDC.…”