Moles and melanoma

Posted on 6 August 2013

How often do you check your skin – and your family’s – for changes? You should be doing it at least once a year says Dr Jens Pieper, a Cape-based GP.

What is melanoma and who does it affect?
Melanoma is the most common cancer today, the most dangerous, and the leading cause of death from skin disease. It affects mainly Caucasian races but there’s an increase in melanoma within other races too, primarily in individuals with a lighter skin tone. We are witnessing an overall increase in the incidence of melanoma, with spikes between the ages of 18 and 28 and in middle age, from 45 to 55.

In South Africa, how many new cases of melanoma are diagnosed annually?
There are no accurate statistics for melanoma in SA at present. However it is possible to get a rough idea from local South African labs who diagnose melanoma histologically. If these figures are extrapolated, we see that five years ago (in 2008) there were 32 cases of melanoma diagnosed per 100 000. In 2013, the number has doubled to 68 per 100 000.

How often should we check our skin and what are we looking for?
Ideally, start checking your and your family’s skin with ‘mole mapping’ once a year (children from the age of 12) and at regular annual intervals after that. Mole mapping captures the entire skin’s surface (total body mapping), after which all moles are individually archived in a magnification between 20 and 40 times. Special software modules analyses each mole and gives your doctor a malignancy potential, which will be shared with you. The higher this potential, the sooner you will be asked to return for a follow-up, if your doctor decides not to remove the mole at that stage. In this way, any deterioration into malignancy can be effectively picked up and treated appropriately, before it becomes dangerous. The technique relies on a diagnosis made from a microscopic picture and enables the detection of any changes long before they become visible to the naked eye.

See your doctor immediately if your moles have:
1.    Grown, are of recent origin, are more than 5mm in diameter, or have changed shape and colour.
2.    An irregular border that may also include odd-looking skin around the mole, giving it the appearance of a ‘fried egg’.
3.    Seem lumpy or have an irregular texture, burn, and itch or just ‘feel funny’.

It’s important to note that only about 25% of all melanomas develop from pre-existing moles, whereas the majority of melanomas appear ‘de novo’, or as a new mole. This is where a baseline total body mapping, done six to 12 months earlier is essential to show up the changes – the de-novo mole – during the follow-up.

What’s the procedure for diagnosing melanoma?
De novo moles and other suspicious lesions have to be removed by excision (cutting out), followed by a histological diagnosis from a pathology lab. Only in this way would you know what you are dealing with. Burning or freezing a mole may not remove all the affected tissue, which could then continue to grow.

Are all cases of melanoma fatal – once diagnosed, what’s the prognosis?
Not all cases are fatal and early detection is the key. Melanoma in-situ, early stage, cut out with a wide enough margin will usually produce a cure. The survival rates with invasive melanoma are less favorable and depend on the staging. There are promising new therapies that may improve the overall survival rates in later stage melanomas.

What measures can be taken to prevent melanoma?
Avoid sun and UV exposure by using protective clothing and sunscreens. UV radiation has increased massively due to ozone depletion and three blistering sunburns will increase your chances of getting a melanoma significantly. Wear protective clothing, apply sunblock every day and get mole mapped annually.

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The information provided in this article was correct at the time of publishing. At Mediclinic we endeavour to provide our patients and readers with accurate and reliable information, which is why we continually review and update our content. However, due to the dynamic nature of clinical information and medicine, some information may from time to time become outdated prior to revision.