By Gary M. White, MD
Many factors impact the choice of therapy for a basal cell carcinoma (BCC). Size, location, and histologic pattern are most important. The patient's cosmetic sensibility also plays a role. For example, Mohs surgery is appropriate for ill-defined tumors on the face, recurrent lesions, large tumors, and those with morpheaform histology. Curettage and electrodessication is appropriate for small nodular or superficial BCCs on the trunk. Surgical excision leaves a straight line scar and is very appropriate for most nodular BCCs that are not candidates for Mohs surgery.
C&D is widely used for the treatment of small, uncomplicated BCCs. The cure rate is high (>95%) [JID 2013:123:1188-96]. However, the resulting scar is on average less pleasing to the patient than those resulting from surgery [JAAD 2014:71:1026-7]. C&D is very appropriate for lesions 1 cm or less, and non-facial lesions. The H zone (nasolabial fold, nasal alae, orbital area and auricular area) in some studies has been associated with a higher rate of recurrence following C&D.
The experienced dermatologist will evaluate a lesion prior to biopsy as to 1) the likelihood that it is a BCC and 2) the appropriate treatment if the biopsy is positive. If the lesion is very likely a BCC and it is amenable to C&D, both biopsy and treatment may be done at that same visit [JAMA Dermatol 2013;149:980-1].
Barlow et al achieved a 5-year cure rate of 96% using curettage alone followed by 20% aluminum chloride application for hemostasis [JAAD 2006;54;1039]. Quoting from the methods section of the article: "Thorough curettage was performed in at least 3 directions to treat the base and a 2-5 mm peripheral margin until only normal dermis remained...A normal base was characterized by a uniform appearance and the texture of firm collagen without residual irregularity." The supposed benefits of curettage without electrodessication include simplicity, lack of equipment requirements, avoidance of potentially hazardous viral smoke plumes, and reduced risk of hyperpigmentation and scarring.
Mohs surgery is the gold standard for the treatment of BCC with a recurrence rate of only 1-2%. Cost limits its use however. For example Mohs surgery is not appropriate for a 4 mm nodular BCC on the back. Mohs surgery should be considered first option for larger lesions (e.g., > 2 cm), recurrent lesions, morpheaform histology, and facial lesions, especially those near the ears, nose, or eyes.
Classic surgical excision with 3-4 mm margins is one of the first-line therapies for BCC. Given clear margins, the cure rate is estimated at 98%. It is usually employed for uncomplicated BCCs at a distance from important anatomic structures. Certain features are associated with a further extension beyond clinical margins or the need for tissue sparing. In these cases, Mohs surgery is typically used. They include proximity to the nose, eyes, or ears, larger lesions, recurrent lesions, and morpheaform histology.
Radiation therapy is a good alternative in certain situations. Virtually any BCC of the face is a reasonable candidate and certain sites are excellent for XRT, e.g., the nasal ala. Large BCCs on the trunk are also reasonable candidates if surgery would be difficult. Cure rates for most BCCs are around 95% [JAAD 2012;67;1235]. For recurrent BCCs it drops down to 90%.
Radiated skin after 20 years may not be as appealing cosmetically, so most patients treated with XRT are usually over 60 years of age but some radiation therapists treat patients as young as 45. Morpheaform histology is usually a contraindication. Potential side effects include hypopigmentation, e.g., in 10% and less likely atrophy. Multiple treatment sessions are usually done over 3-6 weeks.
In one study of 141 BCCs in 117 frail elderly patients, weekly XRT for 6 weeks gave a relapse-free survival after 5 years of 95% [JAAD 2015;73;166].
Imiquimod is approved for the treatment of superficial BCCs. The patient must be an immunocompetent adult, with a BCC no greater than 2 cm in diameter and should not be on the face, head, anogenital area, hands, or feet. Imiquimod is applied 5 days a week for 6 weeks and left on for 8 hours each application. The cure rate has ranged in studies from 69 to 79%.
Off-label use of imiquimod for nodular BCC has been studied. Cure rates for the regimen of daily x 6 weeks may be as high as 70-80%. It is not recommended for recurrent BCC. Elderly patients reluctant to undergo surgery might be good candidates.
Odomzo and Erivedge are FDA-approved for metastatic or locally advanced BCCs that may not be surgically amenable. Side effects are significant.
Cure rates as high as 87% have been reported for PDT-treatment of superficial BCCs. Cosmesis is a selling point and can be excellent. It is not recommended for recurrent lesions and is usually not used for other histologic subtypes. A cure rate of 76% (5 year followup) was found for methyl aminolevulinate PDT treatment of nodular BCC [Arch Dermatol. 2007;143:1131-6].
5-FU 5% BID x 4 weeks is quoted as having a 70-80% clearance rate of small superficial BCCs of the trunk.
Daily sun protection is key although studies have yet to show that sunscreens decrease the development of future BCCs. (Sunscreen use does however reduce the incidence of AKs, SCCs, and melanoma.)
Routine followup should occur for patients diagnosed with either BCC or SCC (keratinocyte carcinoma [KC]). However, the risk of a subsequent KC after the first lifetime KC is significantly lower than after the 2nd, 3rd, or subsequent KC [JAMA Derm 2015;151;382]. In other words, a significant subset of patients diagnosed with their first KC will not develop a second KC (40% if followed for 10 years in the previously referenced study). However, the patient with 2 or more KCs is at high risk for subsequent KCs.
Basosquamous carcinomas are more aggressive, and complete excision with clear surgical margins is indicated.
BCC in very rare cases can metastasize. These are usually large lesions and almost always morpheaform in histology.
Biopsy, curettage and electrodessication, all on the same day, of an obvious basal cell carcinoma.
Homepage | FAQs | Use of Images | Contact Dr. White