Australian researchers have developed the world’s first blood test (pdf) to detect melanoma in its early stages, a potential breakthrough for a cancer that, when detected late, has dramatically lower survival rates.
Scientists at Edith Cowan University conducted a small trial with about 209 people, about half of whom had early-stage skin cancer. The test was able to accurately detect melanoma in about 80% of cases, according to researcher Mel Ziman. Larger clinical trials will now be necessary to determine if the blood test works in larger populations, and can eventually be sold commercially.
Melanoma is not the most common kind of skin cancer, but it is the most serious, according to the American Cancer Society. It is mainly caused by exposure to UV radiation and often starts with a change in a mole or a new growth on skin. According to the study highlighting the results of the blood test, published in Oncotarget, early detection of melanoma results in a five-year survival rate as high as 99%, while patients whose melanoma is detected at a late stage have five-year survival rates of only 15–20%.
“If we can remove the melanoma when it is less than 1mm thick, you have a 98-99% chance of survival,” Mel Ziman, one of the researchers involved in the study, told the BBC. But “as soon as it spreads further into the skin, survival rates drop dramatically.”
Currently, people must rely on dermatologists for skin examinations and biopsies to detect melanoma and other skin cancers. This is problematic for people who do not regularly see or have access to a dermatologist, as well as people who have many moles on their body. (The Skin Cancer Foundation recommends looking for warning signs on a regular basis.) It is not surprising that the test was developed in Australia, where melanoma is the fourth most-common cancer in the country, resulting in 1,500 deaths each year. About 14,000 cases were diagnosed in 2017.
The blood test picks up the melanoma by identifying auto-antibodies produced by the body to combat the cancer’s early growth. The study initially examined 1,627 functional proteins, eventually paring it down to 10 that best indicated the presence of melanoma.
The blood test will undergo clinical trials over three years to improve its accuracy to 90%. Researchers said in a release that they hope it could be approved for use within five years.