From the Guidelines
Salivary gland neoplasms are tumors that develop in the salivary glands, with most occurring in the parotid gland, and can be benign or malignant, with pleomorphic adenoma being the most common benign type and mucoepidermoid carcinoma being the most common malignant type, as stated in the most recent guideline by the American Society of Clinical Oncology (ASCO) 1.
Diagnosis and Treatment
Diagnosis typically involves clinical examination, imaging (ultrasound, CT, or MRI), and fine-needle aspiration cytology. The primary treatment for most salivary gland tumors is surgical excision, with the extent of surgery depending on tumor location, size, and malignancy status.
- For benign parotid tumors, superficial parotidectomy with facial nerve preservation is standard, while malignant tumors may require total parotidectomy with possible neck dissection.
- Postoperative radiation therapy is recommended for high-grade malignancies, positive surgical margins, perineural invasion, or advanced disease, as recommended by the ASCO guideline 1.
- Chemotherapy has limited efficacy but may be used in metastatic disease.
Management of Salivary Gland Malignancy
The management of salivary gland malignancy involves a multidisciplinary approach, with consideration of histology, disease burden and distribution, the patient’s overall health and comorbidities, potential treatment-related toxicities, and function, as stated in the ASCO guideline 1.
- Surgeons should offer open surgical excision for histologically confirmed salivary gland malignancies, as recommended by the ASCO guideline 1.
- Patients with recurrent salivary gland cancer should be evaluated in a multidisciplinary setting, and adjuvant radiation therapy should be planned after revision surgery, as stated in the ASCO guideline 1.
Targeted Therapies
Targeted therapies, such as NTRK inhibitors, HER2-targeted therapies, and androgen deprivation therapy, may be offered to patients with specific types of salivary gland cancer, as stated in the ASCO guideline 1.
- Patients with secretory carcinomas of the salivary glands, harboring NTRK gene fusion, may be offered first-line or subsequent-line NTRK inhibitor therapy.
- Patients with HER2-positive salivary gland carcinoma may be offered HER2-targeted therapies.
- Patients with AR-positive salivary gland cancer may be offered combined androgen blockade.
Recommendation
The primary treatment for most salivary gland tumors is surgical excision, with the extent of surgery depending on tumor location, size, and malignancy status, as recommended by the most recent and highest quality study by the ASCO guideline 1.
From the Research
Definition of Salivary Gland Neoplasms
Salivary gland neoplasms refer to abnormal tissue growths that occur in the salivary glands, which can be either benign (non-cancerous) or malignant (cancerous) 2, 3, 4, 5, 6. These neoplasms can arise in both major and minor salivary glands.
Types of Salivary Gland Neoplasms
The types of salivary gland neoplasms include:
- Benign neoplasms, such as pleomorphic adenoma and Warthin's tumor 2, 4, 6
- Malignant neoplasms, such as mucoepidermoid carcinoma and adenoid cystic carcinoma 2, 4, 5, 6
- Other rare types of salivary gland neoplasms, such as mammary analog secretory carcinoma 3
Diagnosis of Salivary Gland Neoplasms
Fine-needle aspiration biopsy (FNAB) is a commonly used method for diagnosing salivary gland neoplasms 2, 3, 4, 5, 6. The diagnostic accuracy of FNAB can be high, with sensitivity and specificity values ranging from 79.1% to 98% 2, 4, 5, 6. However, the diagnosis of salivary gland neoplasms can be challenging due to the diversity of tumor types and the overlap of cytological features between different entities 3, 6.
Characteristics of Salivary Gland Neoplasms
Some key characteristics of salivary gland neoplasms include: