Can squamous cell carcinoma be treated with radiation therapy?

Radiation Therapy for Squamous Cell Carcinoma

Yes, radiation therapy is an effective treatment option for squamous cell carcinoma, particularly when surgery is not feasible or preferred, though the cure rate may be lower than with surgical approaches. 1

Types of Squamous Cell Carcinoma and Radiation Therapy Indications

Radiation therapy can be used in different clinical scenarios for squamous cell carcinoma (SCC):

Cutaneous SCC

• Early-stage (low-risk) disease: Radiation therapy can be considered when:

  • Surgery is contraindicated or not preferred by the patient
  • The patient has medical comorbidities that make surgery risky
  • The tumor is in a cosmetically sensitive area 1

• Types of radiation for cutaneous SCC:

  • Superficial radiation therapy
  • Brachytherapy
  • External electron beam therapy 1

Head and Neck SCC

• Early-stage (I-II) disease:

  • Either surgery or radiotherapy provides similar locoregional control 1
  • Can be used as primary treatment with curative intent

• Locally advanced disease (III-IV):

  • As adjuvant therapy after surgery, especially with high-risk features (extracapsular extension, R1 resection) 1
  • Combined concomitant chemoradiation is the standard treatment for non-resectable patients 1
  • Radiotherapy with cetuximab has demonstrated higher response rates and longer overall survival versus radiotherapy alone 1

• Organ preservation strategy:

  • For advanced larynx and hypopharynx cancer to avoid total laryngectomy 1
  • Can be used after induction chemotherapy in responsive patients 1

Effectiveness and Considerations

Effectiveness

• For cutaneous SCC: Effective for small localized tumors, but with the understanding that cure rates may be lower than with surgery 1, 2
• For head and neck SCC: Similar locoregional control to surgery in early stages 1
• For locally advanced head and neck SCC: Combined with chemotherapy or cetuximab, provides significant survival benefit 1

Important Considerations

1. Pre-treatment preparation:

   • Dental rehabilitation is indicated before radiotherapy for head and neck SCC 1
   • Nutritional status must be corrected and maintained 1

2. Modern radiation techniques:

   • 3D conformal radiation therapy
   • Intensity modulated radiation therapy (IMRT) 1

3. Potential complications:

   • Higher risk of complications with larger tumor size and higher tumor dose 3
   • For head and neck SCC: Evaluation of thyroid function in patients with irradiation to the neck is recommended at 1,2, and 5 years 1

Treatment Algorithms

For Cutaneous SCC:

1. First-line: Surgical excision with appropriate margins
2. When surgery is not feasible:
   • For low-risk tumors: Consider radiation therapy
   • For high-risk tumors: Consider combination therapy (radiation plus systemic therapy)

For Head and Neck SCC:

1. Early stage (I-II):

   • Either surgery or radiotherapy based on functional and cosmetic considerations

2. Locally advanced resectable disease:

   • Surgery plus post-operative radiotherapy
   • If high-risk features present: Post-operative chemoradiotherapy with platinum-based regimen 1

3. Locally advanced unresectable disease:

   • Combined concomitant chemoradiation 1
   • Radiotherapy with cetuximab as an alternative 1

4. For organ preservation (larynx/hypopharynx):

   • Induction chemotherapy followed by radiotherapy in responsive patients 1
   • Concurrent chemoradiotherapy 1

Follow-up After Radiation Treatment

• Treatment response should be evaluated by clinical examination and imaging (CT scan or MRI) 1
• For head and neck SCC: Physical examination along with radiologic imaging should be included in follow-up 1
• Special attention to treatment sequelae and complications 1

Pitfalls and Caveats

1. Not all SCCs are suitable for radiation therapy:

   • Radiation therapy is not recommended as first-line for high-risk cutaneous SCC 1
   • Patients with massive larynx cartilage invasion should be excluded from organ preservation approaches 1

2. Treatment toxicity:

   • Combined chemoradiation is associated with significant toxicity 1
   • Efficacy in elderly populations may be reduced 1

3. Recurrence management:

   • In selected cases of localized recurrence, re-irradiation can be considered 1
   • For most patients with recurrence, palliative chemotherapy is the standard option 1

Radiation therapy represents a valuable treatment modality for squamous cell carcinoma across different anatomical sites, either as primary treatment or as part of multimodal therapy, with specific indications based on tumor characteristics, patient factors, and treatment goals.