Melanoma blood test could detect early skin cancer

Currently, the most effective way to detect melanoma is by examining the skin and taking a biopsy. A blood test could pick up the cancer much sooner, giving patients better chances of survival.

Researchers from West Australia’s Edith Cowan University have described the test as a “breakthrough”.

Lead researcher, PhD candidate Pauline Zaenker from the university’s Melanoma Research Group, said the test could provide doctors with a powerful tool to detect melanoma before it spreads throughout the body.

Australia has the second highest rate of melanoma in the world, with 14,000 new diagnoses and almost 2000 deaths each year.

Ms Zaenker said identifying melanoma early was the best way to prevent these deaths.

“Patients who have their melanoma detected in its early stage have a five-year survival rate between 90 and 99 per cent, whereas if it is not caught early and it spreads around the body, the five-year survival rate drops to less than 50 per cent,” she said.

“This is what makes this blood test so exciting as a potential screening tool because it can pick up melanoma in its very early stages when it is still treatable.”

At present, the main way melanoma is detected is by a visual scan by a clinician, with any areas of skin that are of concern excised and sent for a biopsy.

Ms Zaenker said while clinicians do a fantastic job with the tool available, relying on biopsies alone can be problematic.

“We know that three out of four biopsies come back negative for melanoma,” she said. “The biopsies are quite invasive, with a minimum of 1cm by 1cm of skin excised from the patient.”

The blood test works by detecting biomarkers – autoantibodies the body produces in response to the melanoma.

In a trial involving 105 people with melanoma and 104 healthy controls, the blood test was able to detect early stage melanoma in 79 per cent of cases.

“The body starts producing these antibodies as soon as melanoma first develops, which is how we have been able to detect the cancer in its very early stages with this blood test,” Ms Zaenker  said.

“No other type of biomarker appears to be capable of detecting the cancer in blood at these early stages.” 

One person who knows first-hand the importance of developing new ways to detect skin cancer is MelanomaWA chief executive  Clinton Heal, who has had 34 secondary tumours removed since he was diagnosed with melanoma at the age of 22.

“At MelanomaWA we see first-hand the importance of early detection and how it’s critical to the long term survival of people diagnosed with melanoma,” he said.

“My primary melanoma was not detected early, and I believe a simple blood test could have drastically improved my melanoma diagnosis and subsequent treatment since.”

Melanoma Research Group head Professor Mel Ziman said he hoped to see a follow-up clinical trial within three years, and a test ready for use in clinics shortly afterwards.

“The ultimate goal is for this blood test to be used to provide greater diagnostic certainty prior to biopsy and for routine screening of people who are at a higher risk of melanoma, such as those with a large number of moles or those with pale skin or a family history of the disease.”

The Cancer Council warns melanomas often have an irregular edge or surface, and may be blotchy and brown, black, blue, red, white or light grey. Left untreated, they could spread deeper into the skin and be carried in lymph vessels or blood vessels to other parts of the body.

At least two in three Australians will be diagnosed with skin cancer before the age of 70.

Cancer Council Australia chief executive Professor Sanchia Aranda described the research as an "interesting development", with larger clinical trials needed to test its impact on survival in the real world.

"It is unlikely that population based screening would be cost-effective, so research would also be needed to determine who would benefit," she said.

"At the moment many melanomas are easily detected early through changes to new or existing spots or moles, so it’s important all Australians keep a close eye on their skin and see their doctor straight away if they notice anything unusual."