When melanoma spreads, survival rates decrease. But the tumor cells responsible have been notoriously difficult to detect. Now, researchers in Australia think they know why.
Although melanoma only makes up around 1% of skin cancers, it is responsible for a significant number of deaths.
The American Cancer Society (ACS) estimate that more than 100,000 people will receive a diagnosis of melanoma in 2020, resulting in approximately 7,000 deaths.
There are several reasons why a person might develop melanoma, but according to the Skin Cancer Foundation, the sun is responsible for most cases. Despite this knowledge, rates of this type of cancer been increasing in recent decades.
Knowing the link between early detection and a 99% 5-year survival rate, a research team at Australia’s Edith Cowan University in Perth has been looking for better ways to diagnose and treat melanoma.
Their findings appear in the British Journal of Cancer.

The first blood test

Back in 2018, the university’s Melanoma Research Group announced the development of the first melanoma blood test.
Existing detection methods for the disease involve a visual scan and biopsies, but these come with issues.
Lead researcher Pauline Zaenker explained at the time: “While clinicians do a fantastic job with the tools available, relying on biopsies alone can be problematic.” Not only are they costly and invasive, but they can be ineffective, too.
Initial trials showed the blood test could detect 79% of early-stage melanoma cases.
It spots autoantibodies made by the body as soon as the cancer develops, and is currently undergoing a clinical trial.
“We envision [the trial] taking about 3 years,” Head Prof. Mel Ziman said, adding: “If this is successful, we would hope to be able to have a test ready for use in pathology clinics shortly afterward.”

Halting the spread

Now though, the same research group has found an effective way to track the development of melanoma and potentially treat it.
Designed in partnership with the Harvard Medical School in Boston, MA, and clinicians from other Australian hospitals, it works by focusing on circulating tumor cells (CTCs) — the cells that allow cancers to spread.
“Cancer spreads around the body when CTCs shed from the primary tumor and travel through the blood to form secondary tumors (metastases) in other organs,” explains lead researcher and Associate Prof. Elin Gray.
Finding these cells, however, is not always easy in melanoma cases. Detection rates can range from as low as 40% to as high as 87%.
“If we can find a way to reliably detect these cells, then we have a chance to stop melanoma in its tracks with a powerful diagnostic tool and perhaps opportunities for therapies in the future,” Prof. Gray says.