Blog

In Greek mythology, Daedalus was an inventor. His inventions—in various iterations from Homer to Pliny—include the axe, plumbline (architectural tool to measure how “plumb” or vertical a line was), glue (fish glue or isinglass, from the floating bladders of fish like sturgeon), and even a colourful dance floor (for Princess Ariadne). However his creative genius was considered too big for a mortal, and he was imprisoned. He attempted to flee the isle of Crete with his son Icarus by designing waxen wings. He instructed his son that the flying altitude was all important—if he flew too low, his wings would get wet in the ocean and curtail his ability to fly; if he flew too high, the sun would melt his wings because they were made of wax. As the story goes, Icarus—consumed by the exhilaration of his newfound ability to fly, and believing he was a veritable superman—does end up soaring too close to the son and perishes.

Melanoma kills one American every hour, although for most Americans it would not feature in their regular lexicon; unlike down under, in New Zealand and Australia—places where everyone has heard of melanoma, the deadly skin cancer. In New Zealand, the annual death from melanoma (329 in 2019) hovers just around the road toll from motor vehicles accidents (341 in 2023).

I have been in skin cancer practice since 1996. I have been humbled to have one of the largest patient series in the world and was honoured–at APAC, Asia Pacific’s largest health forum—with the Ko Awatea International Excellence Award for Leading Healthcare on a Global Scale, with the citation noting my “role in improving skin cancer management, education and patient-centred care internationally, across several countries.” As I said during that award ceremony, these awards are not for me, they are for my patients—people that have come with me all the way deserve more than gratitude. What gives my large patient numbers more potency is the ability to analyse statistics and scores from big data–ultimately it is the human condition revealed in these brief conversations and interactions.

Skin is a finely crafted sense organ, honed by billions of years of evolution. Our only universal organ; and the only sense organ necessary for being. We can exist without hearing, smell, taste or vision but not without touch. Through my explorations in the field of skin cancer, skin bioengineering and skincare, I have learned that humans and human cells have natural imperfections of every kind that end up enveloped within a flawless instrument that has taught me many life lessons. As I mentioned in my TEDx talk, all humans originated in Africa and our skin colours evolved to become darker (to preserve folate in hotter climes) or lighter (to absorb more vitamin D in sun deficient places). But these changes took thousands of years, such timelines posing a challenge to fickle human memories. We live within a definition of our lifespans, so our remembrances often do not reflect reality. We feverishly confuse “culture” as “race” when homo sapiens are a genetically singular species.

I wrote in a previous book, Skin, a Biography (4th Estate, 2013):

It would be easier to understand the Earth’s tilt, and the radiation (both visible and ultraviolet) it is exposed to from the sun, if we imagine a top spinning at a tilt while orbiting an illuminated ball. If you shone a torch at night straight down at the ground, you’d get a smaller circle of light than if you held it at an incline. When held at an angle, the light falls over a wider, more oval area—which explains why the poles end up getting more radiation. Therefore, at different times, the north and the south poles will selectively receive more light, simply because a top that spins at a tilt tends to wobble. However, the southern hemisphere regions are more vulnerable because the ozone layer over it fluctuates and thins out more easily. Why is there greater ozone depletion at the southern hemisphere? This is because the north and south poles have different characteristics: Antarctica is a snowy mountain, while the Arctic is essentially ice floating on water. Snow reflects between 20 to 100 per cent of all wavelengths (depending on how ‘pure’ it is), whereas water only reflects 6 to 12 per cent of visible light (and half that amount of UVB radiation).

Therefore being located close to Antarctica in the southern hemisphere places us at greater risk of melanoma. Fair Celtic skin from the British Isles was not designed to live down under. Green or blue eyes increase your risk of melanoma when compared to dark eye colours by 50%. Redheads have three times the risk, whereas blondes have twice the risk of melanoma when compared to people with dark hair. So what can someone do to reduce their risk? Therein lie lessons in design incompatibility like the story of Icarus.

From my own practice I know that pilots have twice the risk of melanoma. Being high up exposes someone to more solar radiation. One cannot control occupational exposure other than using measures like sunscreens or shades. But there are some lifestyle factors that can make a difference. Meta analyses shows that chronic exposure—such as occurs in farmers or outdoor workers–is not associated with increased risk of melanoma as it causes some crustiness and thickening of skin; but intermittent acute sun exposure is worse.

Recreational sun exposure such as sunbathing, water sports, and vacations have been documented to cause a 60% elevated relative risk of melanoma. In this regard, I must add that I am referring to the more dangerous melanoma skin cancers (and not non-melanoma skin cancers). If you have ever used a tanning bed, research suggests that you already have an approximately 20% increased risk of melanoma; this risk rises by 1.8% with each additional session per year.

Alcohol now appears to be another factor, and this seems independent of skin type. Bloody booze again! I was teaching an international skin cancer course in Australia and the overseas doctors from Europe and America could not believe how much doctors (and people in general) drank down under.

Research suggests that the highest alcohol intake (>3.08 g/day) was associated with a 47% increased melanoma risk compared with the lowest intake (0–0.13 g/day). White wine was worse than red wine, and beer did not show a higher risk specifically. This was explained by the fact that wine has far higher levels of pre-existing acetaldehyde than beer or spirits. Down under one standard drink is 10g (By the way, countries use different standard drink equivalents: Aus/NZ = 10g. UK = 8g. USA = 14g). Simply having a daily drink or greater than 2-4 drinks of white wine a week can therefore increase your risk of melanoma. Your choice of Chardonnay or savoured Sav may be problematic when consumed too often. We conveniently never tend to mention this when we discuss skin cancer, do we? Even worse, in a case of poetic injustice, these tumours tend to be around your midriff where the drink settles. Studies show a positive association between alcohol intake and melanoma risk on the trunk but not for body sites such as the head, neck or limbs. The importance of having alcohol-free days cannot be overstated.

Ultimately, in an Icarian tale retold, evolutionary design catches up with the overlapping ideas of biology and privilege, asking us how much we are prepared to give up today’s addictions to prevent future suffering.

THE END

IMPORTANT: This blog is about science-communication, education, interesting new science, and medical research to do with (mostly) health and skin. It is not individual one-on-one medical advice. Please do not stop any medications without consulting your own doctor.