Treatment Options
The available treatments for localised basal cell carcinoma are:
- Local excision
- Moh's Micrographic Surgery
- Radiotherapy
- Cryotherapy
- Curettage and Electrodesiccation
- Topical imiquimod
- Topical 5-fluorouracil
Management of localised disease
Factors influencing choice of management
Management of a localised BCC is dependent on:
- The size of the lesion
- The location of the lesion
- The rate of growth
- The pathological subtype
- The age of the patient
- The presence of comorbid conditions
- The ease of travel for the patient
Small tumours not on the face
For small, non-aggressively growing tumours on the trunk, treatment with surgical excision, electrodessication or radiotherapy is typically curative in over 95% of cases. Topical treatments have a poorer cure rate, usually from 70 - 80%, but may be appropriate in selected patients. Electrodessication is not suitable for large lesions (over 2 cm) on the torso or extremities, with significantly inferior cure rates. Radiotherapy is reserved for cases where the patient is not fit for surgery or where further surgery would be disfiguring; it is typically avoided in younger patients due to the potential for inducing malignancies.
Aggressive tumours not on the face
For more aggressive or larger tumours, surgical excision, Moh's micrographic surgery or radiotherapy are viable treatment options. Again, primary surgery is the favoured treatment option, with Moh's micrographic surgery reserved for cases where infiltrative or morphaeform pathologies are suspected. Radiotherapy has similar cure rates but is again associated with a poorer cosmesis and risk of malignancy later in life; it is best reserved for elderly patients who are unfit for surgery.
Tumours of the face
Tumours of the head and neck region present special challenges. Cosmetic outcomes are more important and more difficult to achieve for surgeons. Irregular contours and critical structures make radiotherapy more complex to deliver. Repeated interventions can lead to significant deterioration in cosmetic outcome. For small lesions of the face, surgery is associated with improved cosmesis and improved local control over radiotherapy in most cases.
- Dermatologists typically recommend Moh's micrographic surgery for tumours in high risk, cosmetically difficult areas such as the nose, ear, eyelid or nasolabial fold.
- Conventional surgical excision is usually possible for lesions on the cheek or forehead, with the use of an appropriate margin
- Radiotherapy may provide superior cosmesis for some facial BCCs, particularly of the nose, ear or eye regions. It is still inferior to surgical excision but may provide a useful alternative in selected situations.
- Topical treatments may be trialled in this region. Although they have poorer control rates they have the benefit of tissue preservation and superior cosmesis over other methods.
Special situations
- The infiltrative or morpheic basal cell carcinoma pathologies have poorly defined margins and a normal surgical excision will often be inadequate. Surgical excision using Moh's micrographic surgery gives the best outcome for these patients as the margins are confirmed intraoperatively.
- Another important case is when a basal cell carcinoma is accompanied by perineural invasion. This development significantly increases the risk of local recurrence or spread to other body regions (such as the base of skull). If present, Moh's micrographic surgery is typically recommended by dermatologists.
- Finally, recurrent tumours sometimes occur. Re-excision is often required, or alternatively radiation can be used. In high risk or cosmetically important areas Moh's micrographic surgery is also recommended.
Management of Specific Tumour Issues
Perineural Invasion
Perineural invasion is seen in small number of basal cell carcinomas. It is more common in recurrent tumours, although whether it is the perineural invasion that causes the initial recurrence or the treatment which causes perineural invasion to develop is unknown.
There are two types of perineural invasion:
- 'Microscopic' or 'incidental' perineural invasion is when perineural invasion of small nerves is seen on histopathological resection
- Clinical perineural invasion occurs when patients present with neuropathic symptoms due to large nerve involvement, or if named nerves are pathologically involved by tumour.
The management of tumours that have incidental perineural invasion is controversial and is often guided by the presence of other adverse factors such as:
- Tumour size
- Tumour location (high risk areas such as the nasolabial fold, lip or ear)
Following Mohs micrographic surgery, an Australian study demonstrated that rates of recurrence were three to four times higher in patients with perineural invasion (2% vs 8%), regardless of whether radiotherapy was given. Radiotherapy was only given to 12 patients and only one developed recurrence. See the article by Leibovitch et al [1]
Another Australian study identifies patients with incidental perineural invasion as a low risk group who probably derive minimal benefit from adjuvant therapy if that is the only risk factor [2]
Patients with clinical perineural invasion should be considered for radiotherapy to the skull base along the course of the involved nerve.
Management of Specific Sites
I have included this section to aid in exam preparation.
Earlobe
External Auditory Meatus
External Auditory Canal
Upper Lip
Lower Lip
Nose Tip
Nasal Ala
Bridge of Nose
Nasolabial Fold
Periorbital (not eyelid)
Eyelid
Lower Leg
Dorsum of Hand/Foot
Management of metastatic basal cell carcinoma
Disseminated basal cell carcinoma is very rare. Reported incidences of 1/35,000 have been quoted but this figure is questioned due to the lack of cases in the literature. Systemic therapy is required for disseminated BCC, with cisplatin the mainstay of cytotoxic therapy.
Targeted Therapy
Vismodegib is a new sonic hedgehog pathway inhibitor. It binds to the smoothened transmembrane receptor (SMO) and prevents activation. In normal functioning cells, SMO is bound by the PTCH receptor, but released when sonic hedgehog binds to PTCH. PTCH function is often deregulated in basal cell carcinoma, and mutations in the PTCH gene give rise to Gorlin syndrome.
In phase 2 trials, vismodegib has been shown to have response rates of 31% in non-Gorlin patients and over 50% in Gorlin syndrome patients. It has only been well evaluated in patients with metastatic disease or locally advanced disease not suitable for surgery or radiotherapy.
As of February 2014, vismodegib is approved by the Australian Therapeutic Goods Administration and FDA but not approved for subsidy by the PBS [3]
