Melanoma incidence: signs for a decline?

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Published: 22 Nov 2018
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Prof David Whiteman - QIMR Berghofer Medical Research Institute, Brisbane, Australia

Prof David Whiteman speaks with ecancer at the EADO 2018 congress in Barcelona about the changing rates of melanoma incidence.

Prof Whiteman explains some countries which have had years of rising melanoma incidence, such as Australia and Denmark, have seen rates plateau or even decline in recent years due to an increase in public education.

He also shares differing trends across population groups, including that in Australia, New Zealand and the Southern Hemisphere men have double the rate of melanoma compared with women, with the difference particularly considerable among older age groups.

ecancer's filming has been kindly supported by Amgen through the ecancer Global Foundation. ecancer is editorially independent and there is no influence over content.

Two countries in particular where we’re starting to see changes in melanoma incidence are in Australia and New Zealand in the southern hemisphere, which historically have had very, very high rates of melanoma, the highest in the world. But it looks like in the last four or five years rates in those two countries are no longer going up and they might even be going down, certainly in New Zealand. Then in the northern hemisphere really the standout is Denmark. In Denmark rates have been quite high and they’ve been climbing year on year for the past 15-20 years. But the last four or five years they also have seen a plateau in their rates of melanoma which is quite contrasting with the neighbouring countries of Sweden and Norway where in those two countries rates are still climbing upwards at quite a fast rate. So whatever they’re doing in Denmark seems to be working.

Would you say there has been a long-term systematic education?

That’s right. In Denmark they’ve been aware of their melanoma problem for at least two decades and they have been instituting various public education campaigns and also campaigns directed at doctors to identify melanomas. So it seems that those activities are starting to change the rate of melanoma in Denmark.

Are there any countries that have seen an increase in melanoma cases?

Certainly in the UK melanoma rates are climbing steeply and are continuing to climb steeply and they’ve been climbing really quite steeply for at least twenty years or so. It’s attributed to various things, one is the availability of cheap holidays that people in the UK can get to the Mediterranean or the Canary Islands and really when they go there it seems the behaviour of Brits on holiday can be one that’s not sun safe. And measurements have been done, people can get extremely high doses of UV, a one or two week holiday, on skin that is completely unprepared for such an insult. So that’s one likely activity, another is the availability of sunbeds and tanning parlours in the UK and that goes for other parts of northern Europe and North America as well. That seems to be targeted particularly at younger women, that activity and that exposure, so those kinds of things have led to what we think is high levels of UV exposure and therefore high levels of melanoma.

Has analysis revealed any melanoma trends in different population groups?

Yes, they are very interesting questions. They’re not always easy to answer because it depends on what data have been collected by the cancer registries. There are definitely differences by gender, so in Australia, New Zealand and the southern hemisphere men have about double the rate of melanoma compared with women. That’s particularly noticeable in older age groups so as men and women move beyond middle age the curves start to separate and in Australia and New Zealand men have very high rates of melanoma. In Europe, and particularly in the UK, that difference between the sexes is actually much less marked and, in fact, in many historical northern hemisphere locations women have actually had higher rates of melanoma than men. So at the current time approximately equal rates in men and women, so that’s between the genders but certainly with age as well melanoma has an early spike. So there’s a spike of melanoma incidence in young adulthood, up to the 20s or 30s and then it really starts to rise again in late middle age and older age, so people in their 60s and 70s have extremely high rates of melanoma. That’s seen in all countries where melanoma is recorded.

What is the take home message?

The take home message is that melanoma rates can change and it looks like they can be turned around but it takes a lot of effort. It takes a systemic, sustained, committed public health approach to educating the public and to making the environment safer and making it one in which you can actually get your messages to take purchase and change behaviour. Of course, you have to start these campaigns early in a person’s life because the effects of sunlight are cumulative and so if you lose your resolve and you take your foot off the pedal people can easily slip back into a bad pattern of sun exposure. So they take a long-term commitment and it will take decades to see the benefit. So it’s a very hard one, particularly for politicians to want to fund because the payback will be long after they leave office. The benefits will not be seen until a generation has passed. But we know that that can happen and there are plenty of precedents from tobacco control in lung cancer and screening for cervical and breast cancer so that if you make the investment based on good science and you’re prepared to stick the course then you will get the benefits but you have to commit to it.