Basal cell carcinomas (BCCs) are locally destructive malignancies of the skin. They are the most common type of cancer in the western world. The lifetime incidence may be up to 39%. UV exposure is the most common risk factor. The majority of these tumours occur on the head and neck. Despite BCCs being relatively indolent the high incidence means that their treatment now contributes a significant and increasing workload for the health service. A good understanding of the options available is important. Management decisions may be influenced by various factors including the patient's age and comorbidities and the lesion subtype and location. Due to the importance of a good cosmetic and curative outcome for facial BCCs treatment decisions may differ significantly to those that would be made for BCCs arising elsewhere. There is little good randomized controlled data available comparing treatment modalities. Although traditionally standard excision has been the treatment of choice various other options are available including: Mohs micrographic surgery, curettage and cautery, cryosurgery, radiotherapy, topical imiquimod, photodynamic therapy and topical 5-fluorouracil. We discuss and review the literature and evidence base for the treatment options that are currently available for facial BCCs.
Basal cell carcinomas (BCCs) are locally destructive malignancies of the skin. They are the most common type of cancer in Europe, Australia [
The most significant aetiological factors appear to be exposure to ultraviolet radiation and genetic predisposition [
Management is dependent upon a variety of factors, including the location of the lesion, the patient’s age, comorbidities and the type of tumour involved. The location of the lesion is important, as tumours that arise in cosmetically or functionally important areas are best managed with treatments that minimise the amount of tissue removed whilst ensuring a high chance of complete cure. In the elderly population, the slow growing nature of BCCs means that less invasive treatments may be favoured despite the fact that some of these methods have higher recurrence rates. Cystic and nodular BCCs (nBCC) have relatively well defined borders, while morphoeic, micronodular, trabecular, infiltrative and basosquamous BCCs are often less well defined and are also more aggressive [
Over recent years, various treatments beside traditional excision have been tried in an effort to provide better results, in terms of reduction of recurrence, better patient acceptability, and improved cosmesis. Although many treatments are now used for BCCs, there is little research that accurately compares these different treatment modalities against each other for different types of tumours in different locations. As a result of the importance of a good cosmetic outcome when tumours arise on the face treatment decisions may differ significantly to those that would be made for BCCs arising elsewhere. We discuss and review the literature and evidence base for the treatment options that are currently available for facial BCCs.
Standard surgical excision is a highly effective treatment for primary BCC and historically has been the mostly common treatment option. BCCs are generally removed with a predetermined excision margin of 3-4 mm of normal skin. Especially on the face, grafts and flaps may be necessary to close the wound, rather than direct closure.
A study of 2016 BCCs byBreuninger and Dietz[
Although little data exists on the correct deep surgical margin, excision through to the subcutaneous fat is generally advisable. Overall the 5-year recurrence rate after a simple excision of a BCC is reported as being between 4.1% [
Basal cell carcinoma on the face may have a higher degree of subclincal spread than tumours arising elsewhere.Batra and Kelley [
Generally the cosmetic outcome for standard surgical excision is felt to be good [
Various studies of incompletely excised BCCs suggest that not all recur and in a series of 74 patients Griffiths reports residual tumour in just 54% of re-excised tissue [
When incomplete excision occurs on the face there is good evidence to support the need for re-excision. Boulinguez et al. [
Generally standard surgical excision is considered a good treatment option for all BCCs arising on the face with 5-year recurrence rates of anything up to 10% providing adequate margins are taken. We would therefore recommend at least a 3-mm margin for standard surgical excision. While it would seem sensible to take larger margins at the sites where subclinical spread is known to be more extensive, these sites are all of great cosmetic and functional importance and therefore striking the correct balance is necessary while considering the option of Mohs’ micrographic surgery as an alternative.
Mohs micrographic surgery (MMS) was first reported by an American physician and general surgeon, Dr. Mohs, in 1941 [
Studies and reviews have found 5-year cure rates of between 93.5% [
A prospective randomised Dutch trial [
Even primary lesions need to be appropriately stratified to determine the optimal course of treatment [
MMS is more labour intensive and the cost of each procedure is significantly higher than for standard excision. However, in view of the reduced recurrence rate, MMS is cost effective treatment for appropriately selected cases. A recent study comparing Mohs’ surgery to standard excision for facial and auricular nonmelanoma skin cancer found MMS to be more cost effective than standard surgical excision [
Mohs surgery provides the best chance of cure for all BCCs arising on the face with 5-year recurrence rates of anything up to 6.5%. However, due to time and cost limitations, it should be reserved for the treatment of high-risk primary or recurrent BCCs on the face.
Curettage is widely used in management of BCC. The tumour is scraped off with a curette and then the base and wound margin is often treated with electrocautery to control bleeding and destroy any residual tumour. This may be repeated. As excision margins are being destroyed it is advisable to confirm the diagnosis and determine the histological subtype with a preoperative biopsy, especially for facial lesions, unless a very confident clinical diagnosis can been made.
For standard curettage and electrocautery recurrence rates have been reported to be between 7.7% [
A randomised controlled trial comparing a double freeze thaw cycle of cryosurgery after curettage with standard excision for nonaggressive BCC of the head and neck reports recurrence rates of 17.6% and 8.2%, respectively [
Given the disproportionate amount of residual tumour on head and neck wounds and higher recurrence rates curettage and electrocautery is not considered first line treatment for BCCs on the face.
Cryosurgery involves the destruction of tissue using liquid nitrogen. Again, it is advisable to biopsy first to confirm the diagnosis and determine the histological subtype, especially for facial lesions. It is very operator dependant, and there are huge variations in practice. Data is therefore very inconsistent. Cryosurgery tends to be most useful in the treatment of low risk BCCs although good results have been reported following treatment of high risk lesions, either as sole treatment or in combination with curettage.
Recurrence rates are very variable, but when the lesion is carefully selected and in expert hands recurrence rates may be as low as 1% [
Cryosurgery wounds generally heal with minimal tissue contraction, resulting in good cosmetic results. However, a study comparing cryosurgery (20 seconds freeze, 60 seconds thaw 2 × cycles) to standard surgical excision for head and neck sBCC and small nBCCs found no significant difference in recurrence rates at 1-year but significantly worse cosmetic outcomes for those who had received cryosurgery [
Cryosurgery should not be first line in the management of facial BCCs due to the high risk or recurrence and potentially poorer cosmetic outcome.
Carbon dioxide laser ablation has been used in the treatment of BCCs. There are reports of use in combination with curettage for treatment of low-risk BCCs, but supportive data is generally lacking.
Radiotherapy can be used to treat primary, recurrent or incompletely excised BCCs. It encompasses superficial X-ray and electron beam. Brachytherapy is used for contoured surfaces. The cure rates are over 90% for most skin lesions [
A randomised trial by Avril et al. [
In addition, radiotherapy tends to be more expensive than any other form of treatment. A recent prospective study by Lear et al. in Canada [
We believe radiotherapy is a good treatment option for facial BCCs located at difficult sites in patients who are not able to tolerate surgery.
Imiquimod is an immune response modifier. It acts by binding to toll-like receptor. This induces proinflammatory cytokine production and subsequent cytotoxic T cell mediated cell death. It is licensed for use in the treatment of sBCCs.
Vehicle-controlled studies in the treatment of small sBCC by Geisse et al. [
There is some data to suggest that imiquimod may be used in the treatment of nBCCs. A randomized dose-response study reported that 6 weeks after treatment with either a 6- or 12-week course of 7x/week imiquimod histological clearance rates were 71% and 76%, respectively [
In terms of studies specifically focusing on the treatment of facial BCCs with 5% imiquimod Vun and Siller [
Studies have also been done investigating the combination of curettage of nBCC prior to the use of topical imiquimod. Results have been variable with recurrence rates ranging from 6% [
Effective treatment with imiquimod is dependent upon tissue penetration. sBCC may be more amenable to topical treatments as a result of their minimal depth of invasion. The increased depth of nodular tumours results in incomplete tumour penetration with the drug and hence lower clearance rates.
Imiquimod may be an alternative to surgery for patients with primary facial superficial BCCs, but long-term clearance is not as good as some of the other treatment modalities. It is not recommended for recurrent disease but is a good treatment option for elderly frail patients and patients who are not keen on surgical treatment.
Photodynamic therapy (PDT) involves the destruction of sensitised cells by an irradiating light source. A prodrug, either 5-aminolaevulinic acid (ALA) or methyl aminolaevulinic (MAL), is applied to the skin. This is converted intracellularly into protoporphyrin IX by the tumour cells. In the presence of intense red or blue light, a cytotoxic reaction occurs with reactive oxygen in the cell-membranes of tumour cells containing protoporphyrin IX and so the tumour cells are destroyed with sparing of uninvolved skin.
Superficial BCCs have been shown to achieve 87% clearance [
Vinciullo et al. [
Due to the clearance rates being lower than for surgical treatments, PDT is not generally recommended for management of nodular BCCs on the head or neck. While primary superficial BCCs on the face may be amenable to treatment is not recommended for recurrent disease.
5-fluorouracil is a fluorinated pyrimidine that blocks the methylation reaction of deoxyuridylic acid to thymidylic acid and in doing so destabilises DNA. It is sometimes used to treat small, superficial BCCs and should only be used on low risk sites. It therefore is not recommended in the management of facial BCCs.
We have discussed a number of the different treatment options available for BCCs. However, lesions on the face are considered high-risk, and therefore, some of the treatment modalities that would otherwise be considered may not always be appropriate. It is often necessary to a prior histological diagnosis, especially if a destructive treatment is being considered. Mohs micrographic surgery remains the gold standard, but it is not feasible for it to be offered to all. Standard surgical excision gives good results in most cases. Radiotherapy may be considered for patients where surgery is not an option. Other treatment options include curettage and electrocautery, PDT, laser, topical imiquimod and cryosurgery; however, in the majority of cases these treatments should not be first line due to the risk of recurrence but may be a good option in the elderly population. In addition, it is important to consider patient choice, feasibility, side effects, and cosmetic outcome when planning management.