Treatment of Conjunctival Squamous Cell Carcinoma
The primary treatment for conjunctival squamous cell carcinoma consists of local excision with cryotherapy to the edges, combined with topical chemotherapeutic agents such as mitomycin-C or fluorouracil (5-FU). 1
Diagnostic Approach
- Definitive diagnosis should be made according to WHO classification from a surgical biopsy sample 2
- Complete physical examination of the eye and regional lymph nodes is necessary, along with imaging studies to assess lesion extent and potential invasion 2
- Anterior segment optical coherence tomography may facilitate diagnosis and follow-up 1
Primary Treatment Options
Surgical Management
- Local excision performed by a surgeon experienced in eyelid tumors is the cornerstone of treatment 1
- The excision should include assessment of:
- Presence or absence of invasion into underlying tissues (episclera, corneal stroma) 1
- Tumor margins, including deep margin and all lateral margins 1
- Degree of differentiation (well, moderately, or poorly differentiated) 1
- Tumor type (ordinary squamous cell carcinoma, spindle cell variant, mucoepidermoid carcinoma) 1
- Presence of vascular, lymphatic, perineural, intraocular, or intraorbital invasion 1
Adjunctive Therapy
- Cryotherapy to the surgical edges helps eliminate residual tumor cells 1
- Topical chemotherapeutic agents can be used as adjunctive therapy or as primary treatment 1:
- Mitomycin-C
- Fluorouracil (5-FU)
- Note: Interferon was previously used but is no longer manufactured 1
Topical 5-FU as Primary or Adjunctive Therapy
- 1% 5-FU eye drops administered four times daily for 4 weeks has shown effectiveness in:
- Recurrent cases
- Incompletely excised tumors
- Selected untreated cases 3
- Clinical regression typically occurs within 3 months with normal epithelium replacing neoplastic conjunctiva 3
- Side effects include transient toxic keratoconjunctivitis that can be managed with topical therapy 3
Treatment Based on Disease Extent
Localized Disease
- Complete surgical excision with margin control is the treatment of choice 4
- Immediate histological monitoring of surgical margins with frozen sections or Mohs' micrographic surgery allows for smaller margins of excision in the periocular area 4
Regional Lymph Node Metastases
- Surgical resection with lymph node dissection
- Consider adjuvant radiation therapy with or without concurrent systemic therapy
- For inoperable lymph node metastases, combination chemoradiation therapy 2
Distant Metastatic Disease
- Palliative chemotherapy options include:
- Weekly methotrexate
- Combination chemotherapy
- Cetuximab added to platinum-based chemotherapy 2
Risk Factors for Aggressive Disease
- Tumor size >2cm
- Depth >4mm
- Poor differentiation
- Perineural or vascular invasion
- Immunosuppressed patient status 2
- Positive tumor margins at initial resection increase risk of orbital extension and regional spread 5
Follow-up Recommendations
- Regular follow-up is essential for early detection of recurrence
- Treatment response should be evaluated by clinical examination and imaging 2
- Monitor for local recurrence and regional spread, particularly in cases with positive margins at initial resection 5
Cautions and Pitfalls
- Incomplete excision significantly increases risk of recurrence and metastasis 5
- Avoid topical erythropoietin in eyes with existing conjunctival SCC or incompletely removed SCC, as it may be linked to tumor recurrence and intraocular invasion 6
- Maintain high suspicion for perineural invasion as this may be associated with poorer prognosis 4
- Treatment should be tailored to the specific patient/tumor needs and performed by an experienced specialist 1