What are the advantages of Mohs surgery for skin cancer?

The goal of Mohs surgery is to remove skin cancer, whilst doing minimal damage to surrounding healthy tissue.

It is especially useful for skin cancers that have a high risk of recurrence or that have recurred after previous treatment or are located in areas where you want to preserve as much healthy tissue as possible, such as around the eyes, ears, nose, mouth, hands, feet and genitals.

Here, leading plastic surgeon Mr Niall Kirkpatrick explains the benefits of the surgical procedure…
 

What are the advantages of Mohs surgery?

Mohs micrographic surgery is considered the most effective technique for treating many basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs), the two most common types of skin cancer.

As Mohs surgery examines 100% of tumour margins at the time of surgery it spares healthy tissue that would normally be removed with conventional surgery and thus leaves the smallest wound possible. This can reduce the scarring in repairing the wound or reduce the complexity of reconstruction in certain parts of the body.

It is particularly useful in treating infiltrative basal cell carcinomas where the edges of the tumour can be difficult to see such that conventional surgery risks incomplete removal, and also treating very large tumours whereby removing as little healthy skin as possible can minimise the size of the wound.

The cure rate with Mohs surgery, cited by most studies, is between 97% and 99.8% for primary basal-cell carcinoma and up to 95% for recurrent basal cell carcinoma. This compares to a cure rate of approximately 90% for a primary tumour removed by conventional surgery.
 

What other ways are basal cell carcinomas and squamous cell carcinomas treated?

Traditionally, operations for treating skin cancer surgically involve removal of the area affected by the skin cancer together with a suitable margin of healthy unaffected skin around and below the skin cancer, in order to try and ensure that the cancer has been completely removed.

Once removed, the skin is sent to a laboratory for examination by a pathologist to confirm whether the tumour has been completely removed. It usually takes between 1-2 weeks for the pathology report to become available. If the report shows that the skin cancer has not been fully removed a further procedure may be necessary.
 

Are there alternative treatments?

Radiotherapy may be an option for some patients. Radiation oncologists quote cure rates from 90 to 95% for BCCs less than 1 or 2 cm and 85 to 90% for BCCs larger than 1 or 2 cm.

Photodynamic therapy is a treatment that can be used for some skin cancers. It uses a drug, called a photosensitiser which is injected into the bloodstream and taken up by the cancer cells. A specific wavelength of light is then shone onto the area 24-72 hours later. When the photosensitisers are exposed to the specific wavelength of light they produce a form of oxygen that kills nearby cells.
 

How do I know if Mohs surgery is right for me?

Mohs surgery is regarded as the gold standard for treating many basal cell carcinomas and squamous cell carcinomas, including those in cosmetically and functionally important areas as mentioned before. Mohs is also recommended for basal cell carcinomas or squamous cell carcinomas that are large, aggressive or growing rapidly, that have indistinct edges, or have recurred after previous treatment.

Some surgeons are also successfully using Mohs surgery on certain cases of early melanoma; a type of melanoma called lentigo malignant melanoma. This type of melanoma stays close to the surface of the skin for a while. When treating melanoma, the surgeon uses a modified type of Mohs surgery called slow Mohs. It’s called slow because the patient must wait longer for the results. It’s not possible for the surgeon to look at the removed skin and know straight away whether it contains cancer cells. More time is needed.
 

Who shouldn’t have Mohs surgery?

Mohs surgery should really be reserved for the treatment of skin cancers in anatomic areas where tissue preservation is of utmost importance such as the face, hands, feet, nipples and genitals. Mohs surgery is not indicated on the trunk or extremities for uncomplicated, non-melanoma skin cancer of less than one centimetre in size.