Australia and New Zealand have the highest rates of skin cancer in the world.
Between 12,000 and 14,000 Australians are diagnosed with melanomas, the potentially lethal form of skin cancer, every year, and around 1,500 will die from them.
While people with fair skin and freckles are most at risk, even those with dark skin can develop them.
But, now, researchers at Edith Cowan University in Western Australia have come up with a blood test to help detect early-stage melanomas, which could change that death toll dramatically.
The five-year survival rate from a melanoma tumour detected at an early stage could be as high as 99 per cent, compared with 15 to 20 per cent for a later-stage diagnosis.
The head of Edith Cowan University's Melanoma Research Group, Professor Mel Ziman, ((ZIH-mun)) says the new test relies on identifying so-called "auto-antibodies."
"Your immune system’s white blood cells produce antibodies to (fight) foreign invading pathogens like bacterial viruses. But they also produce antibodies to (fight) abnormal cancer cells. They're called auto-antibodies. The immune system then amplifies this signal, producing multiple auto-antibodies to the cancer cells. And these auto-antibodies are expressed at very early stages of the cancer, they're easily accessible in the blood, and so it provides a fantastic chance for identifying early-stage cancer."
Blood taken from more than 200 people, half with melanoma and half without, was tested for 10 "biomarkers," or proteins, although Professor Ziman says the researchers plan to expand the tests.
She says, in more than four out of five cases, the blood test detected early-stage melanomas.
She is also optimistic the new method could be used to help people living outside metropolitan areas get more accurate diagnoses.
Cancer Council Australia chief executive Sanchia Aranda ((SAN-chee-uh ah-RAN-dah)) says she is keeping an open mind about the test for now.
Professor Aranda says, while she is optimistic, many questions remain, including the cost-effectiveness and who would get one.
And she says there is a question of accuracy.
"There are lots of different aberrations that can occur when cancers are being developed, and not all patients produce exactly the same biomarkers in every situation, so it’s that sense that, if it’s not 100 per cent foolproof, you’re probably going to want to have the biopsy taken."
People normally go to their doctors if they have concerns over moles.
Doctor then examine them for what is called the "ABCDE" -- asymmetry, irregular borders, colour, diameter and whether they are evolving, or changing.
Professor Ziman says, under the present system, diagnosis at an early stage can prove challenging for small or thin melanomas, for people with several moles or for people with colourless melanomas.
And she says health professionals' opinions can be dangerously subjective.
"Before they have a biopsy would be the most beneficial time for the blood test to be taken. The problem is that, currently, a patient doesn’t have access to a dermatologist immediately after a suspicious lesion is identified, and so there's a bit of inaccuracy in what’s a melanoma at that stage. So a blood test would help in that identification."
If a clinician suspects a mole may be something more, the next step is a biopsy, where the lesion is cut out of the skin.
Negative biopsies cost Australian health authorities more than $70 million every year.
But patients whose blood tests are positive need follow-up biopsies to confirm the results.
Professor Ziman says she wants to make sure those procedures, which she calls "invasive and expensive," are avoided as much as possible.
But the Cancer Council's Professor Aranda says biopsies are still the best method for now of ensuring a possible cancer is extracted from a patient.
"Because the biopsies are fairly straightforward in small lesions, you have the added advantage that, not only is the biopsy taken, it's actually ... the lesion's excised at the same time, and you only need to get more extensive surgery if, in fact, the cancer’s been found to spread through the tissue surrounding the original lump. And if that’s the case, then no (number) of blood tests could have told you that that was the case. You’ve got to have the lesion excised to do that."
The blood test is not expected to become widely available for another three years.
In that time, Edith Cowan University researchers hope to hold clinical trials and find a commercial partner to produce the test.
Professor Aranda says having certainty is non-negotiable, though.
"While we are optimistic about these new sorts of tests, we’re very many years away from answering the questions about the utility in clinical practice, because you don’t want to make mistakes with identifying a patient as not having melanoma when, in fact, that lesion goes on to behave in malignant ways."
