How successful is Mohs surgery?

Mohs surgery is one of the most successful procedures for the removal of skin cancer, but who is it suitable for? Why, and how is it performed? Expert dermatologist and dermatological surgeon Dr Raj Mallipeddi explains how Mohs surgery is utilised to remove tumours, and what patients can expect after the procedure is completed. 

What is Mohs surgery?

Mohs surgery is a specialised technique which is used to remove skin cancer. It was invented by Dr Frederic Mohs in the United States. It involves excising or removing a skin cancer with a certain margin. Following the removal, the tissue is processed into ‘slides’, which the Mohs surgeon will analyse. By mapping exactly what was removed and comparing it to the patient’s skin, he or she can decide if any tumour may be left behind, letting them go back and remove more tumour until the skin is totally clear. This allows the tumour to be completely removed at a cellular level, which achieves the highest likelihood of cure.

What kind of cancer can Mohs surgery treat?

Mohs surgery tends to be used for higher risk types of skin cancer. These are skin cancers which may be in difficult areas such as the eyes, nose, lips, ears or other parts of the face, and it is used particularly in cases where we need to try and preserve as much skin as possible.

There are also more aggressive types of skin cancer which, on pathology, show that there may be roots under the skin, which we cannot see simply by looking at the surface. By using the microscopic control, this allows us to accurately map out and remove all the tumour cells.

How successful is Mohs surgery?

Mohs surgery is highly effective and is considered to be the gold standard for many higher-risk skin cancers. For skin cancers which are primary or previously untreated, Mohs surgery has a 99% success rate. For those skin cancers which have been treated by other methods but have come back or recurred, this rate may drop slightly.

Mohs surgery is successful not just because of the cure rate, but because of the nature of the related scarring. Sometimes, by taking less skin, we can create smaller wounds in the patient, potentially meaning more minimal scarring. There are multiple advantages to this when surgery is used appropriately. By cutting the skin, invariably, some form of scar will result – which is true of any type of surgery. Most patients, however, are interested in what the scar will look like once it’s fully healed. By minimising the amount of skin removed, this will potentially help create less of a scar.

However, it is important to note that it is not necessarily the removal of the skin cancer by Mohs surgery which causes or creates scarring, but rather the reconstructional closure of the wound once the tumour has been removed.

How is the wound closed after Mohs surgery?

There are different methods by which a wound can be closed. When the wound is very small or superficial, it can, in fact, be left to heal by itself over a period of often a few weeks. This heals beautifully to leave very subtle marks. Other methods include:

1. Closing a wound with stitches made side to side.
2. Using techniques such as using flaps of skin where cuts are made in different directions, to pull skin in.
3. Making a skin graft, where skin is taken from somewhere else to then be sewed on to the defect to effectively resurface it.

Depending on how well the surgery is performed, and the method employed, the degree of scarring may vary, but other factors depending on the individual will affect scarring, such as how well their own body heals. On occasion, we experience unexpected complications such as an infection, which can impact on the final degree of scarring.

What is the recovery like following Mohs surgery?

The recovery following surgery will very much depend on what was performed during the Mohs surgery and the reconstruction following tumour removal. Some tumours are removed quickly, in one stage for example, whereas others may require multiple stages and this will determine how big the final defect may be. This will then determine what type of reconstruction is required and a more complicated or extensive reconstruction will inevitably involve more recovery.

Often, a bandage is applied for two days, after which it can be removed. Anti-scar gels, which are often silicone-based, can be used for several months to optimise the scarring.

Ultimately, the recovery will depend on the extent of surgery and the type of reconstruction which was performed.