Melanoma 'big threat' to NZers

One in five Kiwis is at maximum risk of developing potentially deadly melanoma, according to new international research.

A study conducted at the New York University Medical Centre used a database of 600 New Zealanders to pinpoint the six factors most likely to cause the skin cancer.

Dr Darrell Rigel's findings say people with only one of those factors are three times more likely to suffer melanoma than those without.

People with two or more factors are five to 10 times more at risk and those with three or more are 10 to 20 times more susceptible than the general population.

Rigel created the scale using data from a database of 600 Kiwis kept by the MoleMap melanoma surveillance programme.

Some of the factors come as no surprise - for example, having red or blonde hair or a family history of melanoma. Others include freckling on the upper back and a history of scaly or crusty patches of skin on sun-exposed areas which are often pre-cancerous melanoma.

In addition to the six principal factors, the study identified several other important contributing causes to melanoma.

They include use of tanning beds, having funny-looking or a large number of moles and even being financially secure - more money means more time in the sun on summer holiday, according to the study.

Dermatologist and MoleMap founder Dr Mark Gray estimated a third of Kiwis have at least one factor and one in five has three or more, leaving them most at risk.

Gray said dermatologists were always looking for clues about who was most likely to develop melanoma and the results reinforced the need for Kiwis to be more vigilant about sun safety.

"Every day we are confronted with melanoma cases which simply put are caused by human failure - failure to stay out of the sun, cover up or apply sunblock.

"There is no easy way to tell someone that they are going to die from a disease they could have prevented."

Cancer Society skin control adviser Dr Judith Galtry said the organisation supported any research that could help people assess the risk of developing melanoma. She said Australia and New Zealand melanoma management guidelines recommended people at high risk should be checked with a dermoscope by their GP every six months.

Melanoma is the most serious form of skin cancer It is caused by ultraviolet radiation in sunlight but does not always occur in body parts that have received the most sun exposure.

New Zealanders and Australians have the highest rates of melanoma in the world - approximately 2000 Kiwis are diagnosed with melanoma each year and 250 die from it.

It is the fourth most common cancer in New Zealand and most often occurs in people 50 years or older.

If detected early, most melanomas are curable. In later stages, however, they become more serious.