Overview of Melanoma & Treatment

Overview of melanoma and its treatment in New Zealand

This article provides an overview of melanoma and its current treatment in New Zealand. Other articles in the Diagnosis and Treatment section of this site look in more detail at surgery and further treatment,  new treatments under development and how medicines are brought to market in New Zealand.

Melanoma

Melanoma is the most aggressive form of skin cancer. It is characterised by the uncontrolled growth of melanocytes, the pigment-producing cells which colour skin, hair and eyes. Melanoma is treatable if diagnosed early but if the cancer spreads to other parts of the body (metastasises) the prognosis is poor. Malignant melanoma is the leading cause of death from skin cancer, accounting for nearly 80% of all skin cancer deaths.

Recent studies indicate that New Zealand has the highest incidence rates of melanoma in the world, twice the incidence rate of the US and four times the incidence of Northern Europe In 2007, 2173 new cases of melanoma were registered and 292 deaths from melanoma were recorded in New Zealand. It is the fourth most commonly registered cancer in New Zealand, more common than lung cancer.

There are multiple risk factors for melanoma, all of which are interrelated, making them difficult to separate by importance. However, the main risk factors include: exposure to ultraviolet radiation (UVA and UVB), a history of sunburn in childhood and adolescence, using sunbeds, having many irregular or large moles, a personal or family history of melanoma or being fair-skinned and red-headed.

Early melanoma may not have any noticeable symptoms but melanomas usually appear as a changed or new mole.

Symptoms can often be described by the ABCDE system: (However not all melanoma show these characteristics.)

• Asymmetry: two halves of the mole are different from one another
  
• Border: the edges of the mole are poorly defined. It is ragged, notched, blurred or an irregular shape.
  
• Colour: the colour is uneven with shades of black, brown and tan. Melanomas may also be white, grey, red, pink or blue.
  
• Diameter: there is a change, particularly an increase, in size. Melanomas are usually bigger than the end of a pencil (6mm).
  
• Elevation: as melanoma progresses, part or all of it will become elevated.
  

Melanoma’s disease stage is determined by the thickness, depth of penetration and the degree to which the melanoma has spread to lymph nodes and distant sites in the body. How far advanced the melanoma is when it is diagnosed strongly influences the patient’s outcome. For people who are treated early, when melanoma affects only the superficial layers of the skin, the prognosis is excellent and the disease is often curable. Once the cancer becomes invasive and spreads to other parts of the body, melanoma is very difficult to treat and is usually fatal.

Current Treatment Options for Melanoma

Current treatments for the management of melanoma include surgery, radiotherapy, chemotherapy and immunotherapy. These therapies may be used alone or in combination depending on the stage of the disease.

• Surgery: Melanoma is usually first treated with surgery to remove tumours. This may be a curative treatment option for patients whose melanoma has been diagnosed at an early stage.
• Radiotherapy: This treatment option uses radiation to kill melanoma cells. It can be precisely targeted at just the melanoma, which means it does very little damage to normal tissue. Radiation therapy is usually given over several weeks. Metastatic melanoma responds to radiotherapy but this is only the treatment of choice in certain circumstances.
• Chemotherapy: Chemotherapy aims to destroy cancer cells with specific anti-cancer drugs which stop cancer cells from growing and reproducing, while minimising damage to normal cells. The treatment can be given before or after surgery and is usually given intravenously. Dacarbazine (DTIC) is the common chemotherapy used to treat advanced melanoma. However, DTIC has shown limited success in the treatment of melanoma, and is not thought to improve overall survival.
• Immunotherapy: This involves a group of drugs, such as interferon, that stimulate the body’s immune system. Immune system processes are thought to be important in the development of many cancers. Immunotherapy treatments such as interferon-α may improve outcomes for some patients with malignant melanoma, but are also associated with severe side effects.
  

New Treatment Options for Melanoma

Despite the current lack of effective therapies for metastatic melanoma, scientists have made remarkable progress in unravelling the complex molecular biology of the disease.

This understanding has led to prospective new treatments, some of which look very promising. The most exciting and most advanced of these therapies include vemurafenib (Roche) and GSK2118436 (Glaxo SmithKline), both of which target the BRAF mutation, as well as Yervoy (ipilipumab, Bristol Myers-Squibb), which works to stimulate the body’s own immune response to attack the cancer. See New Treatments

If you have further questions about melanoma and its treatment, we encourage you to talk to your own clinical team.