What is the recommended initial treatment approach for primary squamous cell carcinoma (SCC) of the salivary glands?

Initial Treatment Approach for Primary Squamous Cell Carcinoma of Salivary Glands

Complete surgical resection with appropriate neck dissection is the standard initial treatment for primary squamous cell carcinoma of salivary glands, followed by postoperative radiotherapy in most cases to improve locoregional control and survival. 1

Surgical Management

Primary Tumor Resection

• For major salivary glands:

  • Complete excision of the entire gland is mandatory 1
  • Wide surgical margins must be achieved
  • Nerves should not be preserved at the expense of tumor clearance 1

• For minor salivary glands:

  • Wide radical resection of the tumor with surrounding tissue 1
  • Complete excision outside the capsule for encapsulated tumors

Neck Dissection Guidelines

• T2 high-grade tumors: Routine ipsilateral nodal clearance is standard (Level B evidence) 1
• T1a tumors: Ipsilateral neck dissection should be considered (optional) 1
• N+ disease: Comprehensive neck dissection followed by postoperative radiotherapy 1

Adjuvant Therapy

Radiotherapy Indications

• Mandatory postoperative RT when:

  • Incomplete excision (positive margins) 1
  • Perineural invasion present 1
  • Nodal involvement 1
  • High-grade histology 2

• Optional postoperative RT when:

  • Complete excision achieved but high risk of recurrence 1

Radiotherapy Technique

• Standard fractionation with photons (±electrons) to tumor bed and ipsilateral cervical nodal areas 1
• Neutron therapy can be considered for large-volume residual disease (Level C evidence) 1

Treatment Outcomes and Considerations

Evidence suggests that combined therapy (surgery plus radiotherapy) improves outcomes compared to surgery alone:

• Locoregional recurrence rates: 22.2% with combined therapy vs 43.8% with surgery alone 2
• 5-year disease-free survival: 31.2% with combined therapy vs 25.0% with surgery alone 2

Common Pitfalls and Special Considerations

1. Diagnostic challenges:

   • Primary SCC of salivary glands is rare and must be distinguished from high-grade mucoepidermoid carcinoma and metastatic disease 3
   • Thorough evaluation to rule out metastasis from cutaneous or distant primary sites is essential

2. Treatment planning:

   • Multidisciplinary evaluation is crucial for optimal outcomes 1
   • Aggressive multimodal treatment is necessary for this rare and aggressive malignancy 4
   • Inadequate surgical margins significantly worsen prognosis 5

3. Follow-up:

   • Close surveillance is required due to high recurrence rates
   • Regular follow-up at 3-month intervals is recommended 6

Primary SCC of salivary glands has an aggressive clinical course regardless of treatment approach, with high rates of recurrence and mortality 3. The evidence strongly supports an aggressive initial approach with complete surgical resection followed by adjuvant radiotherapy to maximize locoregional control and improve survival outcomes.