Why has the skin cancer rate increased?
Two in three Aussies likely to be diagnosed with some form of skin cancer by the time they’re 70 years of age. That makes it seem like Australia is in the grip of what looks like a skin cancer epidemic. I even read somewhere (although I cannot find the reference for the life of me today) that skin cancer rates have increased by almost 80% over the last 25 years.
You have to admit, on the surface of it, it’s a pretty scary statistic. BUT just to be clear, that’s not a melanoma statistic – it covers all skin cancers from the less dangerous basal cell carcinomas, the more nasty squamous cell carcinomas and the most dangerous, melanomas.
In better news, Australia no longer occupies its former position as having the world’s highest skin cancer rate. That title has gone to our cousins across the ditch in NZ. But we’re in the top two.
And even better news, the survival rates for those diagnosed with skin cancer have improved really significantly over the last couple of decades. That’s thanks largely to improved screening/earlier detection and improved medical intervention and treatment protocols.
But it got me thinking as to why the incidence rate has increased. Off the top of m, head my ‘gut’ says that we’re all living longer has a lot to do with it. Although I wonder if that’s the only thing. Also I’m a Dr, so I wanted to see if I could dig up some ‘real’, science-based answers.
It’s really interesting what you find. Some information was exactly as I expected. And some was surprising.
Living longer affects the skin cancer rate
We are seeing more skin cancers because as a population, we’re living much, much longer than we were even just 30 years ago. According to the Australian Institute for Health & Welfare, the mean (the average) age of a melanoma diagnosis is 60 for women and 63 for men. But if we look at the average life expectancy (also according to AIH&W), in say 1980, it was around 69-70 for men and 75-76 for women. And it would be safe to say that a LOT of people just weren’t around past 60-ish to have a skin cancer noticed, having already died from heart disease (which is still the biggest killer of Australians – please make sure you’re getting your blood pressure and cholesterol checked at least annually).
Interestingly, melanoma diagnoses rose around 5% per year during the 1980’s at least in part due to the use of solariums and the resulting increase in the exposure to ultraviolet radiation. Whilst melanoma still continues to be diagnosed the diagnosis growth rate slowed in the 90’s due to increased awareness and education programs, such as ‘slip, slop, slap’.
We’re looking for it
We’re also seeing more skin cancers because both patients and doctors are looking for it. It’s one of the reasons that mortality from melanoma has dropped. We’re now finding melanomas more often before they’ve reached a thickness of 1mm – read: much, much less likelihood of having spread and much, much better patient outcomes.
Climate change affects the skin cancer rate (yes, really!)
The one thing you might be surprised I found though, was a paper related to climate change. The point of the paper was that as the earth warms, winters get milder and there are more milder/warmer days (and yes, the science supports this), people spend more time outside being exposed to the sun – no big surprises there. And there was another Australian study that showed that when the temperature outside was between 19-27 degrees C, the chances of sunburn, rather horrifyingly, doubled. And really, how much of our year do we have beautiful weather (a blessing and a bit of a curse).
But Australians (and New Zealanders) cop it even worse than many other countries because of our relative closeness to Antarctica where the ‘ozone layer’ is at its thinnest and we’re exposed to greater than average doses of ultraviolet radiation. The good news is that it’s repairing, but it will take another several decades to happen.
What does all of that mean for you?
If it’s lovely outside (even in Winter), you still need to protect yourself from the sun. And if you’re lucky enough to live in beautiful, temperate Australia (or NZ) or somewhere else where you have wonderful weather, you need to schedule yourself a skin cancer check up at least annually.
You can call our clinics on:
Northern Beaches - 9999 0336