Electrodessication and curettage is a very common procedure used in the treatment of basal cell carcinomas that are generally of small size and located in low recurrence areas of the body (neck, trunk, extremities). The area is first numbed with a local anaesthetic injection and then scraped from surrounding normal skin with a curette (a circular, sharp instrument). An electrosurgical needle is then used to desiccate (heat and dry up) the remaining cancerous tissue. This is repeated for a total of three or four times in succession in order to achieve maximal cure rates. This form of treatment is quick, efficient and cost effective. It is limited however, by leading to higher recurrence rates when treating large lesions and cancers of the mid face. Pain during treatment is minimal and post-operatively the area may feel comparable to a small burn.

The cosmetic result will appear as a lighter (hypopigmented) flat spot that is of similar size as the cancer was prior to treatment. The method requires no stitches, only one post operative visit (usually) and is healed with 10 - 21 days.

The chance of a cure with this procedure is 92 - 93% (this figure would be lower in high recurrence areas, and with treatment of larger and more aggressive tumours). There are no long term side effects, except for scarring as described above.

Cryosurgery is a term given to a procedure that involves the application of a very cold substance in order to destroy tissue. To achieve tumour killing, a tissue temperature of -50C is required. In dermatology, the most frequently used cryosurgical substance is liquid nitrogen (-196C), which is applied using a pressurised canister. No anaesthesia is necessary for small tumours and the application of the freezing spray is felt as a burning sensation. With larger tumours, anaesthetics may be used as may temperature measuring devices in order to monitor the extent of freezing within the cancer. Cryosurgery, like Electrodessication and Curettage, is quick, efficient and cost effective. However, this method should be avoided when treating lesions in high recurrence areas.

The post-operative cosmetic result, follow up care, and healing time is very similar to Electrodessication and Curettage.

The overall chance of a cure with this procedure is 92.5% (as with Electrodessication and Curettage, this figure would be lower in high recurrence areas and with the treatment of larger and more aggressive tumours).

Cryosurgery, in a few cases, has lead to nerve damage and numbness, but in general has no side effects, except for scarring.

Laser Vaporisation is a technique involving the use of the carbon dioxide laser to vaporise away abnormal tissue after the area has been anaesthetised. It may be combined with curettage and is particularly useful in cases of multiple/superficial tumours. Sometimes it can be useful in the treatment of patients with Gorlin Syndrome.

Surgical excision is a technique that involves the use of a scalpel to excise (cut out) the cancerous tissue. The area of the cancer is numbed using a local anaesthetic, and a small measurement of 2-4 mm of normal skin surrounding the lesion is made. The cancer plus surrounding normal skin is then removed by incision with the scalpel blade. Stitches are placed to bring the adjacent wound edges together. In some cases, extra skin may be mobilised or taken from a distant site, in order to cover the surgical defect (flap or graft). Pain during treatment is minimal and post-operatively, may feel comparable to that of a bruise. Surgical excision may require 1-2 post operative visits (including suture removal), and heals more rapidly than that of ED&C and cryosurgery.

The cosmetic result is superior to the previously mentioned techniques, but is dependent upon the size and location of the tumour. The overall chance of a cure with surgical excision may range from 94-98% (This statistic would be lower in high risk areas of the face, and with the treatment of larger and more aggressive tumours.

The long term side effects include scarring, and rarely, nerve damage. An advantage of excision is that the margins of the excision specimen can be checked microscopically by a pathologist.

Micrographic (Moh's) Surgery - In 1941, Frederick Moh's described a microscopically guided method of tracing and removing BCCs. The aim of surgery is to completely remove skin cancer. It is a specialized procedure reserved for those tumours designated as being difficult, more aggressive, large, unusual, recurrent, previously incompletely removed or located at cosmetically sensitive or anatomically important sites. The procedure is a form of surgical excision that has been modified with mapping the margins of the tissue specimen to determine whether tumour remains.

This technique spares normal tissue because of the microscopic control involved. The pain, post-operative cosmetic result, follow up care, and healing time are similar as with standard surgical excision.

The overall chance of a cure with micrographic (Mohs) surgery is 99%.

Radiation therapy, or x-ray therapy, is used much less frequently than in the past, and still may be useful in the treatment of certain BCCs in some patients.

However, when used in some patients with Gorlin (Nevoid Basal Cell Carcinoma) syndrome, radiotherapy may lead to the rapid development of new basal cell carcinomas and therefore should only be used under special/exceptional circumstances! This treatment modality will not be discussed further because of this drastic adverse side effect.

Topical 5-fluorouracil (5-FU) is a topical chemotherapy agent used commonly to treat precancerous lesions known as actinic or solar keratoses. With regard to the treatment of true cancers, it is only effective for the superficial type BCCs. It is usually applied twice daily for 6-12 weeks but the exact regime may vary according to the patients needs, and works by destroying the actively growing cancer cells.

Reported cure rates range from 80-95% when true superficial type BCCs were treated. Side effects include scarring, pigment loss at the treated site, and allergic reactions.

This treatment should be reserved for patients with superficial type BCCs in which no other treatment modality is practical. In addition to being a treatment option, 5-FU may have some preventative value when used daily and/or in combinations with topical Retin A.

This methodology should be strongly considered for patients with Gorlin Syndrome.

View further information about Topical 5-flurouracil (5-FU) at:

http://www.dermnetnz.org/treatments/imiquimod.html

http://www.dermnetnz.org/lesions/basal-cell-carcinoma.html

Oral retinoids, (Roaccutane and Neotigason), are systemic agents derived from vitamin A that are most frequently used for treating severe acne and extensive psoriasis.

These medications have been shown to help prevent the development of new BCCs. Unfortunately, this preventative effect requires very high drug doses with increased frequency of side effects. Also, when the drug is discontinued, relapse of the cancer(s) occurs. Side effects can involve the eyes, bones, liver, nervous system, and muscles. Despite these limitations, oral retinoids should also be a strong consideration for prevention of BCCs in patients with Gorlin Syndrome.

Photodynamic therapy (PDT) is a promising non-surgical technique that involves the systemic or topical application of a photosensitising drug that is preferentially retained in tumours, and with exposure to light of the correct wavelength, results in selective destruction of cancerous cells.

Initial studies with PDT show good cure rates and excellent cosmetic results for superficial tumours. It may become applicable in certain cases of Gorlin Syndrome, but not in children.

Interferon is a naturally occurring human mediator that is under experimental studies for the treatment of BCCs. This substance is injected directly into the cancer three times each week for 3 weeks. Some reports have shown complete resolution of treated tumours, but others demonstrate mixed results.

Side effects include fever, chills, decreased white blood cell count, and pain at the site of injection.

We are indebted to the Gorlin Syndrome Group Medical Advisory Board for their assistance with the production of the above information.