Melanoma Is More Common Than Lung Cancer in Australia (Update1)

Melanoma cases almost tripled in Australia the past two decades, making the potentially fatal skin tumor more common than lung cancer, a government report shows.

Doctors diagnosed 9,524 melanoma cases in 2003 compared with 3,803 in 1983, the Australian Institute of Health and Welfare in Canberra said in a review released today. The incidence rate was 47 new cases per 100,000 people in 2003, 67 percent more than two decades earlier.

The findings indicate a 26-year effort to educate people about the sun's harmful ultraviolet radiation has failed to halt melanoma, even as an anti-smoking campaign cut the incidence of lung tumors, the country's biggest cancer killer, by more than 15 percent since 1983.

``We expect that almost every Australian will get at least one skin cancer,'' James Bishop, professor of cancer medicine at the University of Sydney, said in an interview in Singapore last month. ``It's the Australian disease.''

Australians have the highest rate of skin cancer in the world because of factors such as high ultraviolet radiation levels, lightly pigmented skin and an outdoor lifestyle. Most cases of skin cancer in Australians are the result of excessive sun exposure during childhood, according to the nation's Cancer Council.

The incidence of melanoma in Australia is about six times the level in the U.K. and about three times the rate of the U.S., Bishop said. The incidence of skin cancer, including forms of the disease that don't spread to other tissues, is about four times as prevalent as all other cancers, he said.

Solar Radiation

Australia records some of the highest levels of solar ultraviolet radiation in the world. Relatively clear atmospheric conditions and the influence of ozone depletion over Antarctica contribute to higher levels of solar UV radiation in the southern hemisphere than at similar latitudes in the northern hemisphere, according to the government's Radiation Protection and Nuclear Safety Agency.

Harmful UV rays reach ``extreme'' levels most days between December and January in the most populous cities of Sydney, Melbourne and Brisbane, meaning there is enough ultraviolet radiation to cause sunburn in 15 minutes.

Doctors remove about 720,000 potentially cancerous skin lesions each year and treat more than 382,000 people for melanoma as well as the less severe forms, basal cell carcinoma and squamous cell carcinoma, for which national records aren't kept. In 2003, melanoma killed 1,146 of the country's 20 million people, according to the government report.

Costliest Cancer

``Skin cancer is Australia's most expensive cancer in terms of overall burden on the health system,'' said Ian Olver, chief executive officer of Cancer Council Australia. Many of those who die from melanoma are under 40.

Melanomas less than 5 millimeters (0.2 inch) wide that are treated before the tumor invades the deeper layers of skin, or dermis, are almost all curable. Only one in five patients receiving initial treatment for the most advanced stage of the disease is alive in five years, according to the American Cancer Society.

There were an estimated 106,000 new cases of all types of cancer in Australia last year, compared with 78,857 in 1996, the government report said. Cancers probably killed 39,200 people in 2006, up from 34,857 a decade earlier. In 2003, 6,988 people died from lung cancer and 4,372 of colorectal cancer.

Tobacco Smoking

Lung cancer was the most common form of the metastatic disease in men in 1983, affecting 84.5 per 100,000 people. The incidence measured on an age-standardized basis fell 32 percent to 57.1 cases per 100,000 in 2003, according to the government's statistics, largely because of a decline in tobacco-smoking. The incidence of lung cancer in both sexes was 40.4 per 100,000 in 2003 on an age-standardized basis, the report said.

In 1945, almost three-quarters of adult men and a quarter of adult women smoked, according to the Institute of Health and Welfare. In 2004, 23 percent of males and 19 percent of females aged over 14 years were smokers.

``It's pretty easy to persuade people that smoking is bad for you and that stopping doing it would be a good idea,'' said Bruce Armstrong, professor of public health at the University of Sydney. In contrast, ``the average person thinks sun exposure is great; it's a real part of life. The notion that you shouldn't expose yourself to the sun is far less attractive.''

Public service messages first aired on television in Australia encouraged people to ``slip on a shirt, slop on sunscreen, and slap on a hat'' when they go out into the sun. The campaign improved melanoma awareness and school-age children especially take more precautions to avoid sun damage, Armstrong said.

Going Backwards

``For a while, we seemed to be gaining on the problem and there was more sun protection happening,'' he said. ``That trend has in fact turned around and started to go back again towards less sun protection and more sun exposure, which just illustrates the problem. It is an uphill battle.''

The average age of melanoma diagnosis was 61.3 years for men and 57.5 years for women in 2003. Armstrong said prevalence of melanoma in older men is accelerating.

``As men got older, as they get more disposable income, they increase their level of recreational sun exposure,'' adding to any skin damage that occurred during childhood, he said.

Melanoma is one of the cancers most likely to be diagnosed in people in Australia aged 20 to 35 years, said Bishop at the University of Sydney.

``About 80 percent of teenage girls think that a tan is attractive,'' he said. ``This is a problem that we're dealing with, and we have to get in and change the culture.''

The desire for a year-round tan is fueling demand for solariums or sunbeds. The number of shops offering tanning services in the country's biggest cities more than tripled in the decade to 2006, and increased as much as 10 times in Perth, according to a study published in April in the Australian and New Zealand Journal of Public Health.
source:www.bloomberg.com