Treatment Options for Basal Cell Carcinoma
Surgical approaches are the most effective treatment for basal cell carcinoma (BCC), offering the highest cure rates and should be considered first-line therapy for most cases. 1
Risk Stratification
Risk assessment is essential for determining the optimal treatment approach:
Low-risk BCCs: Small size (<2 cm), well-defined borders, primary (not recurrent) tumors, location on trunk or extremities, and non-aggressive histologic subtype 1
High-risk BCCs: Large size (≥2 cm), poorly defined borders, recurrent tumors, location on face or other critical sites (especially H-zone), aggressive histologic subtype, and perineural invasion 2, 1
Surgical Treatment Options
Mohs Micrographic Surgery (MMS)
- Gold standard for high-risk BCCs with complete margin assessment 1
- Highest cure rates: 99% for primary BCC, 94.4% for recurrent BCC 1
- Recommended for recurrent or poorly defined tumors, sclerosing BCC, and primary carcinomas in areas with predilection for recurrence 2
- Provides optimal cure rate and maximum tissue conservation 2
Standard Surgical Excision
- Appropriate for most primary BCCs 1
- Recommended with 4-mm clinical margins for low-risk tumors 2, 3
- For high-risk tumors, margins of 4-6 mm are advised 1, 4
- 5-year recurrence rates of 12.2% have been reported, with 56% of recurrences identified beyond 5 years of follow-up 2
- Incomplete excision significantly increases recurrence risk (26.8% vs 5.9% with negative margins) 2
Curettage and Electrodesiccation (C&E)
- Suitable only for low-risk, superficial BCCs 1
- Not recommended for terminal hair-bearing areas, lesions extending to subcutaneous fat, or high-risk tumors 1
- Quick and easily performed in an office setting 2
Non-Surgical Options
Radiation Therapy
- Alternative for patients who cannot undergo surgery 1
- Generally reserved for patients >60 years due to long-term sequelae 1
- Effective for both primary and recurrent BCC 1
Topical Therapies
- Imiquimod and 5-fluorouracil (5-FU) are suitable for superficial, low-risk BCCs 1, 5
- Lower efficacy compared to surgical options 1
- 5-FU should not be applied to mucous membranes due to risk of local inflammation and ulceration 5
- Patients with dihydropyrimidine dehydrogenase (DPD) enzyme deficiency should avoid 5-FU due to risk of severe toxicity 5
Cryotherapy
- Consider only when more effective therapies are contraindicated 2
- Higher recurrence rates (6.3-39%) compared to surgery 1
- Limited to small, well-defined, superficial BCCs 1
Photodynamic Therapy (PDT)
- May be considered for low-risk lesions 2, 6
- Aminolevulinic acid (ALA) or methylaminolevulinate (MAL) can be used 2
- Lower cure rates compared to surgical options 6
Advanced/Metastatic BCC Treatment
Hedgehog Pathway Inhibitors
- Vismodegib is FDA-approved for locally advanced or metastatic BCC that has recurred following surgery or for patients who are not candidates for surgery and radiation 7
- Response rates of 30-37.9% in metastatic BCC 1
- Common side effects include muscle spasms, arthralgias, alopecia, dysgeusia, and weight loss 7
- Embryo-fetal toxicity is a serious concern; pregnancy status must be verified before initiating treatment 7
Treatment Algorithm
Assess risk factors to classify BCC as low-risk or high-risk 1
For low-risk BCCs:
For high-risk BCCs:
For advanced/metastatic BCCs:
- Hedgehog pathway inhibitors (vismodegib) for locally advanced or metastatic BCC 7
Important Considerations
- Incomplete excision increases recurrence risk, especially when deep margins are involved 2
- BCCs incompletely excised at the deep margin are particularly difficult to cure with re-excision 2
- When only lateral margins are involved, there is a 17% risk of recurrence, rising to 33% if deep margins are involved 2
- Regular follow-up is essential as 30-50% of BCC patients develop another BCC within 5 years 1
- Due to the slow growth rate of BCC, recurrences are frequently diagnosed beyond 5 years following treatment 2