some clinical notes about types and management of salivary gland malignancy..

1. Salivary Glands Cancer
By
Osama El-Zaafarany

2. Epidemiology
• Salivary gland neoplasms account for 6% of H&N
cancers (35% are malignant).
• Less than 0.3% of all malignancies.
• Approximately 80% of all salivary gland neoplasms
originate in the parotid.
• The male-to-female ratio for malignant salivary gland
tumors is 0.6.
• About 25% of parotid, 40% of submandibular, and
75% of sublingual gland tumors are malignant.

3. Etiology
• Lifestyle: Cigarette smoking has a strong association
with Warthin’s tumor, a benign tumor of the parotid
gland
• Occupational: Hairdressers, rubber manufacturing,
exposure to metal in the plumbing industry and nickel
compounds, and woodworking in the automobile
industry
• Ethnic: Inuit men and women have the highest
incidence rate of salivary gland cancer in the world,
primarily from an excess of lymphoepithelial carcinomas
• Ionizing radiation: (including 131l): risk factor mostly
for mucoepidermoid carcinomas and Warthin’s tumors.
An increased risk has also been observed for
adenocarcinomas among Hodgkin lymphoma survivors.
• Epstein-Barr virus: lymphoepithelial carcinomas

4. Anatomy

6. Pathology
WHO 2005 classification of malignant salivary epithelial tumors

7. Natural History
• Mucoepidermoid carcinoma is the most common
malignant diagnosis (33%), followed by adenoid cystic
carcinoma (24%), polymorphous low-grade
adenocarcinoma, carcinoma ex pleomorphic adenoma.
• Mucoepidermoid carcinoma has higher incidence for LNs
metas.
• Adenoid cystic carcinoma:
 25-50 % distant metas.
 PNI.
 Needs adjuvant RTx.
 Not respond to Taxol.

8. Regional lymph node metastases
• Mainly to levels II & III.
• This figure shows the percentage of LNs
metas in Parotid gland cancers:

9. Risk of positive neck nodes according to summation of
scores and site:

10. Workup
• H&P with bimanual palpation. Carefully examine
cranial nerves and for trismus.
• CT and/or MRI of head and neck.
• PET scan is still investigational for salivary gland
cancers.
• Fine-needle aspiration biopsy.
• Chest X-ray.
• Dental evaluation prior to the start of RT.

11. Staging

14. Treatment Recommendations

15. • Surgery forms the mainstay of defnitive treatment
for salivary gland malignancies.
• Complications of surgery include facial nerve
dysfunction and Frey’s syndrome; (gustatory
flushing, sweating, auriculotemporal syndrome(.
• Superfcial parotidectomy can generally be
performed for:
 low-grade parotid tumors.
 T1–T2 superficial parotid lobe tumors without facial nerve
invasion.
• Neck dissection recommended for:
 clinically +ve LNs.
 high-grade tumors.

16. • Indications for post-op RT are currently
controversial as there is no randomized data
analyzing the role of post-op RTx.
• Consider post-op RTx for:
 PNI.
 close/+ve margins.
 high-grade tumors.
 T3-4 tumors.
 +ve LNs.
 +ve Vascular invas.
• RT alone (definitive) is indicated for medically
inoperable and unresectable tumors.
• LC rates with RTx alone range from 20-80%.

17. • Neutron therapy may achieve better LC for
unresectable or inoperable tumors.
• Brachytherapy or intraoperative RT can be
considered for recurrent tumors.
• IMRT reduces mean doses to normal
structures and allows dose-escalation to
tumor.

18. RTx dose
• Post-op RT :
 -ve margins: 60–63 Gy at 1.8–2 Gy/fx
 +ve margins: 66 Gy at 1.8–2 Gy/fx
 for gross residual disease: 70 at 1.8–2 Gy/fx
• RT alone (definitive): 70 at 1.8–2 Gy/fx
• Elective neck RT: 50–54 Gy at 1.8–2 Gy/fx.
 Ipsilat.
 Levels I-II-III.
 For tumors > 4cm include levels IV, V.

19. Field Arrangements
(Parotid Gland Tumors)
• Two traditional radiation therapy techniques for
parotid gland tumors; unilateral anterior and
posterior wedge pair fields using either:
 4-6 MV photons or 60Co.
 12-16 MeV electron (80% of dose)
in combination with 4-6MV or
60Co photons (20% of dose).
• Target:

20. Metastatic disease
• CAP regimen: cyclophosphamide (500 mg/m2),
doxorubicin (Adriamycin; 50 mg/m2), and cisplatin
(Platinol; 50 mg/m2) on first day of a 28-day regimen.
• The objective response rates to chemotherapy are modest,
ranging from 15 to 50%, and lasting from 6 to 9 months.
• Paclitaxel 200 mg/m2 every 21 days (no response in
adenoid cystic carcinoma)
• Targeted therapy may prove useful in the future as some
histologies express EGFR, C-kit, and/or HER-2

21. Evidence
Role of adjuvant RTx:
Dutch Head and Neck Cooperative Group (NWHHT), 2005:

22. Role of neutron RTx:
University of Washington, 2003:

23. Role of Elective Neck Irradiation
University of California, San Francisco (UCSF), 2007:

24. Follow-Up
• H&P:
 every 1–3 months for 1 year.
 every 2–4 months for second year.
 every 4–6 months for years 3–5.
 annually thereafter.
• Regular head imaging with MRI and CXR
as indicated.
• TSH every 6–12 months if neck irradiated.