The Taranaki rate is 70.3 per 100,000 people. The next-worst, the Waitemata District Health Board region has a rate of 50.2 while the overall New Zealand rate is 51.8.
“So, yes, Taranaki has the highest rate in the world,” said Auckland melanoma specialist surgeon and Melanoma Foundation of New Zealand trustee Richard Martin, who conducted the research with two other Auckland experts.
“The number in Taranaki stands out like a beacon. Taranaki is a rural community, with a lot of elderly men who have been farmers,” he said. “Men over 60 have the highest rate of melanoma.”
Melanoma occurred on the faces, scalps and necks of older men and were associated with chronic patterns of sun exposure.
The rate was 49.8 for the Bay of Plenty and 42.8 for Nelson-Marlborough. Southland had the lowest, at 20.1.
The research, Cutaneous melanoma in New Zealand: 2000-2004, was first published last year in the Royal Australasian College of Surgeons Journal of Surgery and analysed New Zealand Cancer Registry data from 2000 to 2004.
A study of 1995-1999 data put the Taranaki rate at 46.7 per 100,000, the country’s fifth highest. Mr Martin said data for 2005-2009 would shortly be available for analysis and results would be published early next year. “It will be very interesting to see what has happened in Taranaki during the next study period,” he said.
Acknowledging Taranaki was not the only district with retired farmers, Mr Martin said perhaps the Taranaki District Health Board could investigate the high melanoma rate in the region. “Is there something unique about Taranaki?” he said.
The study said despite public health campaigns in New Zealand, the thickness of melanomas at diagnosis had increased from 0.60mm in 1995 to 0.80mm in 2004 and posed a higher mortality risk. Mr Martin said the key to surviving melanoma was early detection. “The earlier it is picked up, the better the outcome. People should be aware of changing lesions and new lesions and get them seen early.”
The study said New Zealand’s high rate of melanoma could be caused by a combination of fair-skinned people living at latitudes equivalent in the northern hemisphere to Spain and North Africa, the ozone hole over the country and a lack of pollution to absorb ultra violet radiation.
Public awareness campaigns, changes to sun-seeking behaviour and earlier detection were essential to improved prognosis. Australia had better awareness of and education about melanoma and it seemed sun protection messages were not being absorbed in New Zealand, it said.