Researchers from QIMR Berghofer Medical Research Institute have found that Australia no longer has the highest per capita rates of invasive melanoma in the world, after being overtaken by New Zealand.
The study, which has been published in The Journal of Investigative Dermatology, found that rates of invasive melanoma in Australia have started to decline and are predicted to keep falling over the next 15 years. Invasive melanoma is the deadliest form of skin cancer, which is capable of spreading to other parts of the body.
Researchers compared the rates of melanoma in six populations over a 30-year period from 1982 to 2011. The six populations were Australia, New Zealand, the United Kingdom, Norway, Sweden, and the caucasian population of the United States.
The researchers found that melanoma rates in Australia increased from about 30 cases per 100,000 people in 1982 and peaked at nearly 49 cases per 100,000 people in 2005. The rates then declined to about 48 cases per 100,000 people in 2011. Invasive melanoma rates in New Zealand reached about 50 cases per 100,000 people in 2011.
Professor David Whiteman, who led the study, said Australia was the only one of the six populations where melanoma rates had begun to fall overall.
“We think the main reason for this decline is that Australia has put a huge effort into primary prevention campaigns since the 1980s,” Professor Whiteman said.
“Australians have become more ‘sun smart’ as they have become more aware of the dangers of melanoma and other skin cancers. Schools, workplaces and childcare centres have also introduced measures to decrease exposure to harmful UV radiation.
“This has contributed to a decline in melanoma rates in people under the age of about 50.
“Unfortunately, rates of melanoma are still increasing in people over the age of about 50. This is probably because many older people had already sustained sun damage before the prevention campaigns were introduced, and those melanomas are only appearing now, many decades after the cancer-causing exposure to sunlight occurred.”
However, despite the fall in average melanoma rates per 100,000 people, the overall number of invasive melanomas diagnosed in Australia is still rising and is expected to increase from 11,162 cases per year from 2007-11, to 12,283 cases per year from 2012-16.
Professor Whiteman said this was due to the ageing of the Australian population, as well as overall population growth.
“Melanomas occur most commonly in older people. As Australia’s population ages, the number of melanomas diagnosed will continue to increase,” he said.
“The picture in Australia at the moment is mixed. While it’s good news that average melanoma rates have started to fall, the fact that the actual number of cases is still rising is bad news.
“Australians can’t afford to become complacent. It’s crucial that people of all ages protect themselves from the sun by wearing a hat and protective clothing, using sunscreen, and, where possible, by staying out of the sun during the hottest part of the day.
“As the numbers of people being diagnosed with melanoma increases, governments will need to invest significant amounts of funding in melanoma treatment in the years to come. A strong case can therefore be made to invest more in melanoma prevention.”
The researchers also used recent trends to predict invasive melanoma rates between 2011 and 2031.
Australia’s melanoma rates are predicted to keep falling to about 41 cases per 100,000 people in 2031. New Zealand’s rates are expected to start declining from about 2017 onwards and reach approximately 46 cases per 100,000 people by 2031. Rates in the UK, Sweden, Norway and the caucasian population of the USA are predicted to keep increasing until at least 2022.
The numbers of people dying from melanoma are also increasing across all six populations, but are highest in Australia and New Zealand.
The study was funded by the National Health and Medical Research Council (NHMRC).