Signs and risk factors of melanoma

Signs of melanoma

 The ABCD and EFG rule is a tool used by doctors to help them look for characteristics of skin damage when diagnosing melanomas.

ABCD signs

Asymmetry Are the halves of each spot different?
Border Are the edges uneven, scalloped or notched?
Colour Are there differing shades and colour patches?
Diameter Is the spot greater than 6 mm across, or is it smaller than 6 mm but growing larger?

EFG signs

Some types of melanoma, such as nodular and desmoplastic melanomas, don’t fit the ABCD guidelines.

Elevated Is it raised?
Firm Is it firm to touch?
Growing Is it growing quickly?

How do I spot a melanoma?

New moles mostly appear during childhood and through to the age of 30 to 40. However, adults of any age can develop new or changing spots. It is important to get to know your skin and check it every 3 to 6 months.

To check your skin, make sure you are in a place with good light, undress completely and use a full-length mirror to check your whole body. For areas that are hard to see, use a handheld mirror or ask someone to help. It is also a good idea to take a photo of your moles and spots so that you can compare them with an older photo to see if one has changed.

How melanoma looks can vary greatly. Look for spots that are new, different from other spots, or raised, firm and growing. If you have lots of moles, a melanoma usually stands out and looks different from other moles. A melanoma is usually brown or black, but it can also be pink.

Even if your doctor has said a spot is benign in the past, check for any changes in shape, size or colour. If you notice a new or changing spot, get it checked as soon as possible by your doctor.

Who is at risk?

While anyone can develop melanoma, the risk is higher for people who have:

• unprotected exposure to UV radiation when the UV index is 3 or above, particularly a pattern of short, intense periods of sun exposure and sunburn, such as on weekends and holidays
• had significant UV exposure when they were young
• lots of moles (naevi), especially if the moles have an irregular shape and uneven colour
• pale or freckled skin, especially if it burns easily and doesn’t tan
• fair or red hair, and blue or green eyes
• a previous melanoma or other type of skin cancer
• a strong family history of melanoma (see below)
• a weakened immune system due to medical conditions or from using immunosuppressive medicines for a long time.

Family history and melanoma

Less than 2% of melanomas are linked to an inherited faulty gene. You could have an inherited faulty gene if 2 or more close relatives (parent, sibling or child) have been diagnosed with melanoma, particularly if they were diagnosed with more than one melanoma, or if they were diagnosed with melanoma before the age of 40.

People with a strong family history of melanoma should take extra care with sun protection and regularly check their skin carefully for new moles or skin spots. From their early 20s, they should consider having a professional skin check by a doctor.

If you are concerned about family risk, talk to your doctor about being referred to a family cancer clinic. Visit Centre for Genetics Education to find a family cancer clinic near you. To learn more, call Cancer Connect on 13 11 20.