Melanoma

Melanoma is a skin cancer that begins in the cells that give your skin its colour. These cells (melanocytes) clump together to make the brown spots we call moles. Melanoma can develop in an existing mole or can start as a new spot.

Melanoma begins in a deeper layer of the skin than non-melanoma skin cancer. It can grow and spread more quickly than non-melanoma skin cancer. It can spread to other parts of your body through your bloodstream if it is not treated early.

Melanoma is the most serious type of skin cancer and the most life-threatening.

The main cause of melanoma is lifetime exposure to ultraviolet (UV) light from the sun, including sunburns at any age. Aotearoa New Zealand has very high UV levels and a high rate of melanoma. Tanning sunbeds are another strong source of UV light.

Excessive UV light damages the cells (the building blocks) in your skin. They then grow in an abnormal or uncontrolled way and become cancerous.

Most melanomas are in people older than 50. The risk increases as you age, but younger people can also get melanoma. 

You have a higher personal risk of melanoma if you:

• have a light skin colour
• have blonde, light or red hair, and blue eyes
• form freckles and sunburn easily
• have lots of moles (50 or more)
• have large, irregularly shaped or unevenly coloured moles
• have had skin cancer before
• have whānau who have had skin cancer
• spend a lot of time outdoors
• have lowered immunity from other health conditions or medicines.

Melanomas are often first noticed as an unusual looking freckle or mole that might itch or bleed.

Signs a mole could be a melanoma include it:

• is new
• looks different to the others around it
• is changing in size, thickness, shape or colour
• has started to itch, bleed or cause pain
• has an uneven (asymmetrical) shape or an irregular edge
• has different colours within it (possibly black, blue, white or red)
• is not healing after being knocked or damaged.

If you are concerned about any spots on your skin, have them checked by your healthcare provider.

Melanoma New Zealand has an ABCDEFG early detection system for melanoma and a video guide to skin self-checks. Use them when you check your own skin.

Early detection – Melanoma New Zealandexternal link

You can find images of melanomas on DermNet. 

Melanoma — DermNetexternal link

Your healthcare provider will examine your skin and any moles that are new or have changed.

They may be able to reassure you there is no skin cancer, or you could have something that needs a closer look. They may use a dermatoscope (a small skin microscope) to give them a better view.

If you have a suspicious mole that could be melanoma, your healthcare provider is likely to recommend surgery to remove all of it. This is called a diagnostic excision. 

You will be given a local anaesthetic to numb the skin. The mole is removed whole with a narrow margin of healthy skin. It is sent to a laboratory to confirm whether it contains cancer cells and what type. You will be given stitches (sutures) to help your skin heal.

You may be referred to a more specialised healthcare provider for this surgery.

• The laboratory report should guide whether you need any more investigations or treatments. 
• If it is found to be melanoma, you are likely to need another surgery to take a wider margin of healthy skin from the site.
• If the melanoma was in its early stages and was removed successfully before it had spread, you might not need any further treatment. It might be cured. The specialist would want to keep an eye on the site to make sure it does not come back.

Stages of melanoma

If you have melanoma it will be placed in a category (stage) from 0 to 4. The treatment you need will depend on the stage.

Melanoma may be staged through a combination of:

• the laboratory looking at it once it is removed to see how deep and thick it is
• blood tests
• looking at the nearby lymph nodes (this is called sentinel node biopsy)
• scans such as ultrasound and CT scans.

The melanoma will then be classed as:

Stage 0 — abnormal cells are only found in the epidermis (outer layer of your skin) — this is called melanoma in situ.

Stage 1 — the melanoma is no more than 2 mm thick.

Stage 2 — the melanoma is more than 2 mm thick, with no spread to your lymph vessels or lymph nodes.

Stage 3 — the melanoma has spread to your lymph vessels or lymph nodes. It can be any thickness.

Stage 4 — the melanoma has spread to other parts of your body.

Melanoma on most parts of the body can be cured with local surgery (diagnostic excision) if they are found at an early stage (0, 1 or 2). This is possible for 90% of early-stage melanomas.

Most malignant melanomas need a bigger area of surrounding skin to be removed once the laboratory has confirmed the diagnosis. This is called a wide local excision. It is often done by a plastic surgeon.

If the remaining skin cannot be pulled together and stitched you may need a skin graft. This means taking skin from another part of your body to put over where the melanoma was removed from.

Advanced melanoma

When melanoma spreads beyond the skin to other parts of the body it become more difficult to treat. If your cancer is more advanced, you may be referred to an oncologist (a cancer specialist). They may recommend additional treatments.

For more advanced melanoma you may need a combination of treatments, including:

• surgery
• drugs that kill cancer cells (chemotherapy)
• drugs to stimulate your immune system (immunotherapy)
• radiation therapy (x-ray therapy).

Depending on the stage of melanoma, you may need surgery to remove all the lymph nodes in the surrounding area. Lymph nodes are important sites in the spread of cancer.

If your melanoma was stage 1 or 2 (not spread outside the skin), you will need to have a check-up every 3 to 6 months for 5 years after your surgery. Your healthcare provider will do this, unless you choose to see a private dermatologist or plastic surgeon.

As part of your follow-up your healthcare provider will explain self-examination. This is how to check for any new or changing moles or lumps on your skin.

If your melanoma was more serious – stage 3 or 4 (spread locally or around your body), you will be followed up by hospital specialists. This will be a plastic surgeon or an oncologist (cancer doctor).

You can reduce your risk of skin cancers whatever your age. Keep yourself and your tamariki (children) safe from the sun.

Be sun safe

• Try to avoid the sun between 10am and 4pm, September to April.
• Find shade outdoors, if possible.
• Cover up by wearing long-sleeved tops and pants.
• Wear a wide-brimmed hat and UV-protective sunglasses.
• Use sunblock of at least SPF 30 on exposed skin.

Do skin checks

Check your own skin about every 3 months. This will help you spot any changes early. Regular skin self-checks are important for all adults, but particularly if you:

• are aged over 50
• have a family history of skin cancer
• are at higher risk of getting skin cancer
• have had skin cancer.

Even if your melanoma has been cured, you may get another one. It is important you keep checking your own skin and to attend follow-up appointments with your healthcare provider.

Melanoma New Zealand has an ABCDEFG early detection system for melanoma and a video guide to skin self-checks. Use them when you check your own skin.

Early detection — Melanoma New Zealandexternal link

Photographic checks

If you have a higher risk of melanoma, you may consider having a photographic skin check (mole map) with with a healthcare company that specialises in this. 

Once someone has been diagnosed with cancer, we know there are some difficult days ahead. No matter where you are on the cancer pathway, there is always someone to connect with for support.

There are local services available to help make things easier for you and your whānau.

Melanoma New Zealand provides support including free counselling for you, your whānau, and your friends.

Counselling services — Melanoma New Zealandexternal link

There are a number of benefits of belonging to a support group.

• Cancer support (search) — Healthpointexternal link
• Health-based support groups