SYDNEY - Merkel cell carcinoma (MCC), a rare skin cancer is more aggressive than the deadly skin disease melanoma, according to an Australian study revealed on Friday.

Scientists in Western Australia (WA) discovered that survival rates for people with MCC were far worse than those with melanoma, which has been widely regarded as the most deadly form of skin cancer.

They also found that WA had the highest rates of MCC in the world, with 215 cases diagnosed between 1993 and 2007.

Among those cases, just 64 percent of patients were still alive after five years compared to 90 percent of those with melanoma.

Lead researcher Professor Lin Fritschi from the WA Institute for Medical Research, said while MCC was an aggressive form of skin cancer it was still relatively uncommon.

"We don't want everyone worried because we had 215 cases in 13 years," she told Australian Associated Press (AAP).

Fritschi said the rate of melanoma in Western Australia was much higher, with more than 1000 cases diagnosed each year.

MCC occurs most often on the sun-exposed face, neck, arm and lower leg. It takes the form of pink lumps on the skin - compared to melanomas which are blackish in color.

Those most likely to develop MCCs are older men, people with a history of skin cancer and those with suppressed immune systems due to liver and kidney transplants.

Fritschi said that MCCs were often mistaken for the less aggressive and most common form of skin cancer, basel cell carcinomas (BCCs).

However, even when they were correctly diagnosed, removed and the patient treated with radiotherapy, the tumours were still prone to reappear.

The study by Fritschi and her research colleagues has been accepted for publication in the British Journal of Dermatology.