Analysis of the results of treatment of patients with malignant tumors of the salivary glands

Objective: improve results of the treatment of patients with malignant salivary gland neoplasm (MSGN).

Materials and methods. Analysis of 417 patients suffering from MSGN treated in the Federal State Budgetary Institution “N.N. Blokhin Russian Cancer Research Center” from 1988 to 2014. All the subjects were divided into 4 main groups according to the treatment assigned: group of the surgical treatment – 27.3 % (n = 114), group of the combined treatment (surgery and radiotherapy (RT)) – 54.0 % (n = 225), group of the complex treatment (surgery, radiotherapy and chemotherapy) – 10.5 % (n = 44), group of conservative treatment (radiotherapy and/or chemotherapy) – 8.2 % (n = 34).

Results. Best 5-year disease-free survival (DFS) was observed in patients with localization of the tumor process in the minor salivary glands (MSG), mucosal tunic (MT) of mouth (73.2 ± 5.5%) and parotid gland (62.3 ± 3.3 %), while the lowest survival rate was observed in tumors of sublingual salivary gland (0%) (median was not achieved, p = 0.07). Depending on the morphological variants the best 5-year DFS was observed in groups of myoepithelial carcinoma, and acinar cell carcinoma: 81.3 ± 9.8 and 79.1 ± 8.4 %, respectively (median was not reached, p > 0.05); the worst survival rate was observed in patients with squamous cell carcinoma, carcinoma of the salivary ducts and adenocarcinoma: 45.7 ± 15.5; 50.3 ± 12.7 and 53.0 ± 5.5 %, respectively (median was not reached). In poorly differentiated tumors (G3 ) 5-year DFS was lowest and was equal to 32.7 ± 4.1 %, while in G1 tumors – 83.6 ± 3.1% (p = 0.000001). In G3 tumors addition of radiotherapy to the surgery significantly reduces the incidence of local recurrence - from 51.4 % (surgical treatment alone) down to 33.8 % (combined treatment) (p = 0.08). There was a significant decrease in 5-year disease-free survival rate from 74.2 ± 2.6 % without any adverse pathological signs down to 37.9 ± 5.4% in the presence of these signs (p = 0.000001). Cervical lymph node dissection is absolutely indicated for tumor localization in submandibular salivary gland, as it reduces an incidence of local recurrence: 15.8 % versus 25.9 % in the group without lymph node dissection, p> 0.05. In case of other MSGN localizations, prophylactic lymphadenectomy does not improve long-term outcomes. Radiotherapy in the post-op period significantly improves long-term results of treatment in comparison with a group of preoperative radiotherapy (local recurrence rates are 29.5 and 9.7 %, respectively, p = 0.0002). The use of chemotherapy can be justified in case of neoplasms with poor differentiation (G3 ) since this significantly reduces an incidence of distant metastases (17.6 and 9.1 % in groups of the combined treatment and in the group of conservative chemoradiotherapy respectively, p > 0.05). 

1. Белоус Т.А. Эпителиальные опухоли слюнных желез: Дис. … канд. мед. наук: 14.00.14. М., 1978. 243 с. [Belous T.A. Epithelial tumors salivary glands: thesis Cand. med. Sciences. 14.00.14. Moscow, 1978. 243 p. (In Russ.)].

2. Adenoid Cystic Carcinoma – A rare Differential Diagnosis for a mass in the External Auditory Canal [Электронный ре- сурс]. 12.02.2015. Режим доступа: http://www.ncbi.nlm.nih.gov/ pubmed/25738012.

3. Armstrong J.G., Harrison L.B., Spiro R.H. et al. Malignant tumors of major salivary gland origin. A matched-pair analysis of the role of combined surgery and postoperative radiotherapy. Arch Otolaryngol Head Neck Surg 1990;116:290–3.

4. Byers R.M., Jesse R.H., Guillamondegui O.M. et al. Malignant tumors of the submaxillary gland. Am J Surg 1973;126:458–63.

5. Carcinoma of the external auditory canal and middle ear: therapeutic strategy and follow up [Электронный ресурс]. 12.02.2015. Режим доступа: http://www.ncbi.nlm.nih.gov/ pubmed/15611900.

6. Chen A.M., Bucci M.K., Weinberg V. et al. Adenoid cystic carcinoma of the head and neck treated by surgery with or without postoperative radiation therapy: prognostic features of recurrence. Int J Radiat Oncol Biol Phys 2006;66(1):152–9.

7. Davies L., Welch H.G. Epidemiology of head and neck cancer in the United States. Otolaryngol Head Neck Surg 2006;135:451–7.

8. Ellis G.L., Auclair P.L. Tumors of the salivary glands. Atlas of Tumor Pathology, third series, Fascicle 11. Washington, DC: Armed Forces Institute of Pathology, 1996. P. 39–63, 135, 136, 318–324.

9. Eneroth C.M. Salivary gland tumors in the parotid gland, submandibular gland, and the palate region. Cancer 1971;27:1415–8.

10. Hartford A.C., Palisca M.G., Eichler T.J. et al. American Society for Therapeutic Radiology abd Oncology (ASTRO) and American College of Radiology (ACR) practice guidelines for intensity-modulated radiation therapy (IMRT). Int J Radiat Oncol Biol Phys 2009;73(1):9–14.

11. Holmes T., Das R., Low D. et al. IMRT Documentation Working Group. American Society of Radiation Oncology recommen￾dation for documenting intensity-modulated radiation therapy treatments. Int J Radiat Oncol Biol Phys 2009;74(5):1311–8.

12. Lee N.Y., O’Meara W., Chan K. et al. Concurrent chemotherapy and intensitymodulated radiotherapy for locoregiolnaly advanced laryngeal and hypopharyngeal. Int J Radiat Oncol Biol Phys 2007;69(2): 459–68.

13. NCCN Clinical Practice Guidelines in Oncology. Salivary Gland Tumors. Head and Neck Cancer. 2013. Version 2. P. 1.

14. Pinto A.E., Fonseca I., Martins C. et al. Objective biologic parameters and their clinical relevance in assessing salivary gland neoplasms. Adv Anat Pathol 2000;7:294–306.

15. Renehan A.G., Gleave E.N., Slevin N.J. et al. Clinicopathological and treatmentrelated factors influencing survival in parotid cancer. Br J Surg 1999;80:1296–300. 16. Shah J.P., Patel S.G., Sing B. Head and neck surgery and oncology. Salivary Tumors 2008. P. 240–250.