What are the treatment options for Basal Cell Carcinoma (BCC)?

Treatment Options for Basal Cell Carcinoma (BCC)

Surgical excision with histological margin assessment is the gold standard treatment for basal cell carcinoma, with Mohs micrographic surgery being the preferred technique for high-risk lesions, offering the lowest recurrence rates of 1% for primary BCC and 5.6% for recurrent BCC. 1, 2

Risk Stratification for Treatment Selection

Treatment selection should be based on risk assessment of the BCC:

Factors influencing prognosis and risk:

• Tumor size: Larger tumors have higher recurrence risk
• Tumor site: Central face, especially around eyes, nose, lips, and ears have higher risk
• Definition of clinical margins: Poorly defined lesions have higher risk
• Histological subtype: Infiltrative, micronodular, morpheaform subtypes have higher risk
• Histological features: Perineural/perivascular involvement increases risk
• Previous treatment failure: Recurrent lesions have higher risk
• Immunosuppression: May increase recurrence risk 1

Treatment Options Based on Risk Classification

For Low-Risk BCC:

1. Standard surgical excision

   • 4mm margins for low-risk lesions
   • <2% recurrence rate at 5 years following histologically complete excision 1
   • Good cosmetic results, especially when performed by experienced practitioners

2. Curettage and cautery (C&C)

   • Suitable only for small, well-defined, nodular or superficial BCCs
   • 5-year cure rate of 92.3% for selected primary BCC 1
   • Not recommended for facial lesions (higher residual tumor rate of 47%)

3. Cryosurgery

   • Effective for superficial and small nodular BCCs
   • Double freeze/thaw cycles recommended for facial BCCs
   • 5-year cure rates up to 99% in expert hands 1

4. Topical therapies

   • Imiquimod 5% cream
   • 5-fluorouracil
   • Best for superficial BCCs ≤2cm 2

5. Photodynamic therapy (PDT)

   • Effective for superficial and thin nodular BCCs 2, 3

For High-Risk BCC:

1. Mohs micrographic surgery (MMS)

   • Gold standard for high-risk and facial BCCs
   • Allows intraoperative analysis of 100% of excision margin
   • 5-year recurrence rates: 1% for primary BCC, 5.6% for recurrent BCC 1, 2
   • Particularly valuable for recurrent tumors and those in cosmetically sensitive areas

2. Wide surgical excision with margin control

   • 5-10mm margins for high-risk lesions 2
   • Consider frozen section assessment
   • Higher recurrence rates compared to MMS 1

3. Radiation therapy

   • Option for non-surgical candidates
   • 5-year recurrence rates of 8.7-10% 1, 2
   • Contraindicated in genetic conditions predisposing to skin cancer and in younger patients
   • Valuable as adjuvant therapy for extensive perineural involvement 1

4. Hedgehog pathway inhibitors

   • Sonidegib (Odomzo) and vismodegib
   • FDA-approved for locally advanced BCC that has recurred following surgery or radiation therapy, or for patients who are not candidates for surgery or radiation therapy 4, 3
   • Reserved for inoperable cases or when surgery and radiation are contraindicated 2

Treatment Selection Algorithm

1. Confirm diagnosis with biopsy if clinical diagnosis is uncertain
2. Assess risk factors to classify as low-risk or high-risk BCC
3. For low-risk BCC:
   • Standard excision with 4mm margins is first choice
   • Consider C&C, cryosurgery, PDT, or topical therapies for small superficial lesions in non-critical areas
4. For high-risk BCC:
   • Mohs micrographic surgery is preferred
   • If MMS unavailable, wide excision with 5-10mm margins and careful histological assessment
   • Consider radiation therapy for elderly patients or those who cannot undergo surgery
5. For advanced/inoperable BCC:
   • Hedgehog pathway inhibitors (sonidegib or vismodegib)
   • Consider multidisciplinary tumor board discussion 2

Important Considerations and Pitfalls

• Long-term follow-up is essential: A significant proportion of recurrences occur more than 5 years after treatment, especially for high-risk tumors 1
• Recurrent BCCs have higher failure rates with all treatment modalities 1, 2
• Avoid C&C for high-risk facial lesions - associated with high recurrence rates 1
• Radiation therapy is often reserved for patients older than 60 years due to concerns about long-term sequelae 1
• Surgical margins should correlate with the likelihood of subclinical tumor extensions - deeper margins through subcutaneous fat are generally advisable 1
• Patient factors including general fitness, coexisting medical conditions, and use of antiplatelet or anticoagulant medication should be considered when selecting treatment 1

Following treatment, clinical follow-up is recommended every 3-6 months for the first 2 years, and annually for at least 5 years, with patient education on sun protection, self-examination, and warning signs of recurrence 2.