Return of sun revives the spectre of a killer

By Martin Johnston

Trying to persuade the young to protect themselves against the risk of melanoma far in the future is an ongoing challenge.

Photo / Getty Images
Photo / Getty Images

Gambling with your health is second nature to young people. The potential threat of deadly melanoma is too far in the remote distance of adulthood to deter them from the present allure of having a sun-tanned body.

"Lectures don't work," my 14-year-old daughter told me when I nagged her about sunscreen and hats after her first, fortunately mild, dose of sunburn for the summer.

The Health Promotion Agency, one of the SunSmart organisations, has devised an alternative to parental lectures, which it hopes will turn the tide on teenagers' chronically sun-dumb behaviour and New Zealand's sad status as the country with the world's highest incidence of melanoma, the most serious form of skin cancer.

In the decade to 2009, its annual incidence of the disease rose from about 35 new cases per 100,000 people, to 38. Over 2000 new cases are diagnosed each year, and more than 300 people die from melanoma.

Otago University research among children has shown high rates of sun-smart knowledge, such as using sunscreen to avoid skin cancer, but their behaviour doesn't match their knowledge: only half reported using it. Half said they wore headgear to stop sunburn and only a quarter wore the recommended wide-brimmed hat, bucket hat or cap with flaps.

Cap with flaps! What worse fashion crime could there be for a teenager!

A third said their friends thought a suntan was a good thing and the same proportion reported having a dose of sunburn the summer before.

"Teenagers aren't terribly motivated by the threat of skin cancer that may or may not happen down the track," said Health Promotion Agency adviser Wayde Beckman.

To tap into the need for something more immediate, the agency has begun a new scheme at summer events and on Facebook called "Don't let the sun get under your skin." Teenagers are invited into a camera booth and two face shots are taken: one under normal light and a second under special lighting that can show invisible sun damage that can lead to early wrinkling and skin damage.

The picture can't predict cancer risk, but the message that is delivered - without parental lecturing - is that the sun exposure that causes skin damage can also cause skin cancer.

"They are appealing to their vanity," said Barbara Hegan, the Cancer Society health promotion adviser on skin cancer control. "That's consistent with what the research points to."

But the agency is hardly taking the country by storm. It ran the camera tent at three events last summer, its first season, and will take it to 12 this summer, including a surfing competition at Auckland's Piha beach next month. It is trying to make the most of the 120 to 150 people snapped per day by encouraging some to agree to having the photos of their sun-damaged faces exposed to the world - and their friends - on Facebook.

Ms Hegan said, when asked if New Zealand was doing enough to promote the sun-smart message, "We do our best with what we've got."

Dr Richard McKenzie of the National Institute of Water and Atmospheric Research (Niwa) links New Zealand's high melanoma rate to its being significantly closer to the equator and thus subject to more UV than the ancestral home in northern Europe of much of the country's white-skinned population.

Melanoma in New Zealand is so overwhelmingly a Pakeha disease that the Ministry of Health says "there would be little point in comparing ... rates between ethnic groups".

Niwa says our summer UV levels historically have been increased by the dispersed effects of the seasonal ozone hole over Antarctica, but this problem is gradually abating. We also have higher summer UV levels than equivalent latitudes in the Northern Hemisphere do, partly because of Earth's elliptical orbit around the sun. This puts the south slightly closer to the sun during the southern summer than the north is during the northern summer. Another factor is comparatively clear air over New Zealand.

Otago University epidemiologist Dr Mary Jane Sneyd said not only was the melanoma rate rising but lesions at diagnosis were thicker - "in spite of about 20 years of health promotion campaigns which were aimed at prevention first and early diagnosis".

"Thicker melanomas have a poorer prognosis, a much higher death rate," she said.

"As a country, New Zealand has the highest incidence rate of melanoma in the world. Queensland [a state but not a nation] has a higher rate."

Dr Sneyd has developed a melanoma-risk prediction model, like the statistical model now used by doctors for predicting a person's five-year risk of having a heart attack or stroke.

She wouldn't give details because she was trying first to have the model published, but said it drew from among the established melanoma risk factors such as number of blistering sunburns - "whether you sit out in the sun and fry yourself or not" - skin type, number and type of moles, age, family history of melanoma and personal history of non-melanoma skin cancer.

"It will give the GP an idea what sort of risk the person is at, whether they need to be really proactive at prevention, whether they need to be proactive in early diagnosis."

Most people who are diagnosed with melanoma are cured - by having the lesion and a wide margin around it surgically removed before cancer cells have spread.

The outlook becomes bleaker if there is any spread. Typically the disease is fatal within a year for about 50 per cent of people in whom it has spread to any organs when diagnosed; and within five years for more than 30 per cent if it has spread to lymph nodes at diagnosis.

But new hope of medical treatment is gradually building for those with terminal melanoma, although Pharmac, the Government's buyer of medicines, is not convinced the benefits are enough to justify the high cost.

The new class of drugs are called B-RAF inhibitors. They are targeted at the 40 to 60 per cent of malignant melanoma patients who have a particular gene mutation which makes their tumours susceptible to the medicine. Roche's version, vemurafenib, is registered for use in New Zealand, and GlaxoSmithKline makes dabrafenib, which is still experimental, although GSK has sought registration in the United States and Europe.

"B-RAF inhibitors represent probably the biggest advance we've seen in melanoma for 20 years," said Roche (NZ) general manager Stuart Knight.

Cancer specialist Dr Mike McCrystal said one of his metastatic melanoma patients was still alive after three years of B-RAF tablets, although he was an exception.

"You sometimes get fantastic responses, but very brief - on average seven to eight months. You can see things responding beautifully in front of your eyes, things that were pretty resistant to other forms of treatment, just melting, but before long you will see things growing again. The cancer seems to develop a resistance pattern fairly quickly."

Despite that, the new drugs had transformed the treatment of metastatic melanoma. "Often we were looking at a situation where we couldn't help at all. These days you can buy people a little bit of time."

Pharmac's pharmacology and therapeutics advisory committee (PTAC) in February recommended refusal of Roche's application for state funding of its drug, despite noting the great need for new melanoma medicines because of the poor response of most patients to the currently funded therapy dacarbazine.

"The committee considered that overall vemurafenib was a very high-cost treatment that provided only small, short term, benefit," PTAC's minutes state.

Mr Knight said Roche was still evaluating if it could come up with a new proposal to address PTAC's concerns, although he noted Pharmac's cancer committee endorsed funding vemurafenib, subject to the priority of this being dependent on successful pricing talks.

Roche charges more than $14,000 including GST a month for its drug. However, it does not charge for the first month, nor for the eighth and any succeeding months of treatment.

GSK gives its drug to several patients at no charge on a "compassionate programme" because it is not yet registered, but there is concern about how long it takes to get on the scheme for people who often haven't got long to live anyway.

GSK New Zealand's medical director, Dr Ian Griffiths, said it was running the scheme because the options for people with advanced melanoma were so limited and its drug was still going through regulatory approval.

"The quid pro quo for us is that it provides us with some information ... on what the outcomes are."

Enrolling patients was time consuming because of the need for the patient to be tested to confirm they had the genetic mutation, the need for other clinical information to be gathered, and the patient and doctor consent requirements.

While the B-RAF inhibitors struggle to gain a foothold in New Zealand's cash-tight state-funding system, further developments are on the horizon with the so-called MEK-inhibitor class.


Q&A: Sun safety

Q: Why is the sun such a problem for our skin?

Ultra-violet radiation (UV) from the sun is crucial for life, but too much of it can kill us. UV radiation from the sun or indoor tanning devices is considered to be the likely cause of more than 90 per cent of skin cancers in New Zealand, including melanoma, the most deadly form.

Q: What are our main protections from the sun?

Health authorities advise to regularly apply broad spectrum sunscreen when outside during the day from September to April, wear a wide-brimmed hat, long sleeves and sunglasses and get into the shade. These measures are often needed on cloudy days too.

Q: Is getting a suntan dangerous?

Maybe. Blistering sunburn increases the risk of melanoma in later life.

Q: What about solariums?

Using a sun-lamp or sun-bed increases the risk.

Q: How can we reduce skin cancer risk?

By UV protection, especially for the fair-skinned, by being aware of sinister changes in moles and freckles and by having a regular skin check with a doctor.

Q: Isn't sun exposure important for vitamin D?

Ultra-violet B radiation from the sun is the main source of vitamin D for most people in New Zealand. Low vitamin D levels are linked with weak-bone disorders and there is growing evidence of links to many other conditions, including cardiovascular disease and multiple sclerosis.

Q: How much sun should we get for vitamin D?

The Health Ministry and Cancer Society advise that from May to August, most people should aim to get some midday sun, such as by walking - physical activity promotes increased vitamin D production - with the face, arms and hands uncovered. From September to April, take outdoor physical activity in the early morning or late afternoon to avoid the peak UV time. But some, including those who have a history of skin cancer or sun-damaged skin should use protection at all times.

- NZ Herald

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