Surgical Treatment for Melanoma

Melanoma is primarily treated with surgery. Surgical treatments can be divided into three main categories:

  • Surgical treatment of the primary melanoma
  • Surgical treatment of the lymph nodes
  • Surgical treatment of metastases (spread of melanoma).

    A detailed explanation of the new drug treatments is found on the next page: Drug Treatments for Melanoma

Surgical Treatment of the Primary Melanoma

Why Does My Small Melanoma Need Such a Big Excision?

When melanomas grow on the surface of the skin they enlarge in diameter. This happens because melanoma cells multiply and develop muscle fibres, which gives them the ability to move along the surface of the skin. Some melanoma cells move more quickly than others and spread further away from the main tumour. This results in a melanoma which is surrounded by individual scattered cells that are not visible. The deeper a melanoma has penetrated into the skin, the wider the scatter on the surface. When treating the primary melanoma, it is necessary to ensure that all the invisible scattered cells are removed, otherwise the melanoma will regrow in the same site. This is done by excising (cutting out) a safety margin around the biopsy site of the primary melanoma. This is termed a wide local excision. The size of safety margin is determined by the depth of the original melanoma because the deeper the melanoma, the wider the scatter effect on the surface. Thin melanomas need a 0.5 cm margin, while thicker melanomas require a 2 cm margin of safety. Most of the time the defect that is created with a wide local excision can be closed with a skin flap. In the lower leg, however, there is often not enough stretch in the surrounding skin to be able to do a flap, so one has to resort to doing a skin graft.

Surgical Treatment of the Lymph Nodes

Why do I Need All of My Surrounding Lymph Nodes Removed?

Until very recently (July 2018), it was thought that it was necessary to do a completion block/lymph node dissection (remove all the remaining lymph glands from a lymph node area where melanoma has spread) in all patients with lymph node/gland metastases, even patients where there were only small deposits of melanoma in the sentinel lymph node. It was thought that this could improve the overall cure rate, but we now know that it does not, because a significant percentage of patients who have spread to lymph glands also have undetected spread elsewhere in the body. Patients who have small melanoma metastases detected in their sentinel lymph gland do not need to immediately proceed to a completion block dissection. It is safe to monitor these patients by doing regular ultrasound scans of the remaining lymph glands every 3 to 6 months. If, while screening, new melanoma is detected in any of the remaining lymph glands, it is then necessary to proceed to do a completion lymph gland dissection. In patients who have large deposits of metastatic melanoma in lymph glands (that can be easily felt on clinical examination), it is necessary to remove those glands as part of a completion block dissection. This prevents further spread and controls the melanoma in that area. This surgery is performed under general anaesthesia and usually takes about two and a half hours. Patients are required to stay in hospital for at least a night.

Surgical Treatment of Systemic Melanoma Metastases

Is Surgery an Option if My Melanoma has Spread?

If a melanoma has managed to spread via the blood stream to a distant organ (systemic metastasis) and that metastasis can be removed surgically (i.e. the metastasis is not in a part of the body where too much damage would be done to normal structures while taking out the metastasis), surgery remains a great option because one is then 100% sure that the metastasis has been completely removed. Even if a cure is not achieved, the survival time with surgery can be significantly longer than that obtained with a combination of drugs and radiotherapy. Where possible, surgery is offered as a treatment for spread to organs. Only if surgery is not technically possible, or if there are too many sites of spread, or one has a high risk of developing other metastases does one consider the need for treatment with drugs or radiotherapy.