Basal Cell Carcinoma and Squamous Cell Carcinoma Treatment Guidelines

Introduction to Treatment Options

The National Comprehensive Cancer Network recommends surgical excision as the most effective first-line treatment for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), with cure rates approaching 100% for accessible lesions 1, 2

For low-risk BCC, standard excision with 4-mm clinical margins is a primary surgical option, using linear closure, second intention healing, or skin graft 1, 3
Curettage and electrodesiccation (C&E) can be used for low-risk BCC in areas without terminal hair growth, with the caveat that treatment must be changed to excision if adipose tissue is reached 1, 4
Radiation therapy is an option for nonsurgical candidates with low-risk BCC, generally limited to patients older than 60 years due to long-term toxicity risks 1, 3
For high-risk BCC, Mohs micrographic surgery (MMS) or resection with complete circumferential peripheral and deep margin assessment (CCPDMA) is preferred for margin control 1, 3

For low-risk SCC, standard excision is the first-line treatment with the highest cure rates 2
Mohs micrographic surgery is an option for margin control in cosmetically sensitive areas for low-risk SCC 2
Radiation therapy is an effective option for selected patients with low-risk SCC, particularly those with large or multiple lesions who refuse surgery 2, 5
For high-risk SCC, MMS or wide local excision is mandatory, and radiation therapy is considered for nonsurgical candidates 2

Adjuvant radiation therapy is indicated for positive margins after MMS/CCPDMA, substantial perineural involvement, and regional lymph node involvement 5, 6, 7
Hedgehog pathway inhibitors (vismodegib or sonidegib) can be used as adjuvant therapy for BCC with positive margins after MMS/CCPDMA 1, 3

SCC has a significantly higher metastatic risk than BCC, particularly with regional lymph node involvement, necessitating more aggressive surgical management including lymph node dissection when nodes are positive 5, 6, 7
Topical therapies and photodynamic therapy have established roles for low-risk superficial BCC, but lack sufficient evidence for invasive SCC 2

C&E should not be used on terminal hair-bearing skin for BCC, as follicular extension reduces effectiveness 1, 4
Topical therapies should not be used for nodular or invasive SCC, as evidence is insufficient and cure rates are unacceptably low 2
Radiation therapy should not be used in patients with genetic conditions predisposing to skin cancer or connective tissue diseases 5, 7
Radiation alone should not be used for SCC with parotid parenchymal involvement, as superficial parotidectomy is mandatory for improved disease-specific survival 5, 6, 7

The National Comprehensive Cancer Network recommends that superficial basal cell carcinoma does not require excision and can be effectively treated with non-surgical alternatives, including topical imiquimod, 5-fluorouracil, photodynamic therapy, or cryotherapy, provided the lesion meets low-risk criteria 8, 9

The American Academy of Dermatology suggests classifying the lesion as low-risk versus high-risk based on NCCN criteria, which includes location, size, borders, and histologic pattern 8, 10
Low-risk superficial BCC characteristics include location on the trunk or extremities, well-defined borders, primary lesion, no immunosuppression, and superficial histologic pattern confirmed on biopsy 10

The National Comprehensive Cancer Network states that standard excision with 4-mm clinical margins has the highest cure rate and allows histologic margin assessment 8, 9
Curettage and electrodesiccation is an acceptable option for low-risk lesions, but with critical caveats, including never using in terminal hair-bearing areas and switching to excision if adipose tissue is reached during curettage 8, 9, 11
Topical imiquimod 5% is an option, with a composite clearance rate of 75% and 2-year sustained clearance of 79% 8
Topical 5-fluorouracil has a treatment success rate of 80% at 12 months, but causes moderate-to-severe local reactions 8
Photodynamic therapy has a 5-year recurrence rate of 20% and superior cosmetic outcomes compared to cryotherapy 8, 12
Cryotherapy has 5-year cure rates up to 99% in expert hands, but requires double freeze-thaw cycles and has a 15% recurrence rate at 1 year 8, 12

A 2013 randomized trial compared non-surgical options for superficial BCC, with imiquimod having an 80% treatment success rate, MAL-PDT having a 73% treatment success rate, and 5-FU having a similar success rate to imiquimod 8

The National Comprehensive Cancer Network recommends surgical excision for high-risk locations, aggressive histology, recurrent lesions, poorly defined borders, and perineural involvement 8, 9, 10
Mohs micrographic surgery is the recommended treatment for these high-risk features, with 5-year cure rates of 99% for primary and 94.4% for recurrent BCC 10

The National Comprehensive Cancer Network suggests that histologic verification of clearance is not routinely performed with non-surgical therapies, and clinical assessment at 12 weeks post-treatment is standard 8
Long-term follow-up is essential as recurrences may appear beyond 5 years 9