What is melanoma?

Melanoma is a form of cancer that develops in the skin’s pigment cells (melanocytes).

Melanocytes produce melanin to help protect the skin from ultraviolet (UV) radiation i.e. sunlight. When melanocyte cells aggregate together in the skin during childhood or adolescence they form a mole.

Most moles are quite safe, however sometimes the melanocytes in a mole begin to grow and divide in an uncontrolled way. If they start to grow in a unregulated way, either expanding outwards or down into the lower layers of the skin, they can become a melanoma.

Melanoma is the most serious form of skin cancer and grows very quickly if left untreated. It can spread to the lower part of your skin (dermis), enter the lymphatic system or bloodstream and then spread to other parts of the body e.g. lungs, liver, brain or bone.

What causes melanoma?

The main preventable cause of melanoma is overexposure to UV radiation from the sun or things such as solarium tanning machines (sunbeds). There are many risk factors that increase the chances of melanoma, including people with fair skin, a high mole count, family history and a pattern of sunburns throughout life, especially during childhood.

Importantly, melanoma can occur anywhere on the skin, even in areas that receive little or no sun exposure e.g. inside the mouth or on the soles of your feet.

Is melanoma inherited? 

Melanomas themselves are not passed on from person to person but our risk of melanoma certainly is hereditary - it is strongly affected by our genetic background. Rarely, a specific faulty gene that causes high melanoma risk may be passed from one generation to the next. But for most people it is the combination of a lot of genetic differences that pushes our risk up or down: such as our different skin colours, the way we react to the sun, the number of our moles, and other invisible effects of our genetic makeup.

Can melanoma be prevented?

The good news is that if detected early, melanoma can be effectively treated.

That’s why new moles or existing moles that have recently changed appearance must be checked by an experienced skin specialist. In fact, you should have a regular skin check at least once every 12 months to maximise the chances of picking up melanoma early.

Of course, the most effective way to prevent melanoma is to practice sun safety at all times (especially with children). This means avoiding exposure to the sun during the hottest parts of the day, as well as protecting your skin with sunscreen, clothing and a hat whenever you’re outside (even on cloudy days). See the Preventing Melanoma section of this site for more information.