Researchers from the University of Dundee, UK, presented the work that could lead to such a blood test at the 9th National Cancer Research Institute (NCRI) Cancer Conference in Liverpool, UK.
The test would examine DNA shed from tumor cells into the bloodstream and look for chemical alterations to the gene TFP12, which normally plays an anti-cancer role by preventing healthy skin cells growing out of control.
Melanoma is the least common form of skin cancer, but it is the one responsible for the most deaths.
The cancer is much more difficult to treat once it starts to spread. But detecting whether it has started to spread is also very challenging.
Anti-cancer gene acquires chemical tags that switch it off
However, Dr. Tim Crook, a consultant medical oncologist at Dundee, and colleagues found that in patients with melanoma, the TFP12 gene acquires chemical “tags” known as DNA methylation. These tags switch off the gene’s ability to help prevent healthy cells turning into cancer cells.
Plus, they also discovered that the extent of methylation in the gene reflects whether or not the melanoma has started to spread.
TFP12 methylation was lower in tumors in their early stages, whereas more advanced tumors showed more highly methylated forms of the gene.
The team concluded that measuring the extent of TFP12 methylation in DNA shed from tumor cells that ends up in the bloodstream could be a way to test how advanced the melanoma is.
Dr. Crook says:
“By using a blood test, we have the basis of a simple and accurate way of discovering how advanced the disease is, as well as an early warning sign of whether it has started to spread. This would give doctors and patients important information much sooner than is possible at the moment.”
“There’s increasing evidence that the latest treatments are more effective in these early stages,” he says, adding, “if we can identify patients whose cancer has only just started to spread, this would significantly improve the chances of beating the disease.”
In the same study, the team also discovered another gene, NT5E, that undergoes methylation changes as melanoma progresses.
As the cancer first develops, NT5E is methylated and switched off, but then, if it becomes unmethylated again, it spurs the cancer to spread more aggressively.
The researchers suggest NT5E offers a potential target for new melanoma treatments, particularly for tackling more advanced stages where the cancer has spread to the brain, lungs and other organs.
Panel of biomarkers for melanoma
Another of the researchers, Charlotte Proby, professor and Cancer Research UK dermatologist at Dundee, says:
“The switching on and off of certain genes seems to affect when, where and why the melanoma spreads. Our goal is to develop a panel of similar biomarkers that will help us to accurately detect those patients needing extra treatment to fight their melanoma.”
The Leng Foundation, The Medical Research Council, Barts and the London Charity, The Brain Tumour Research Charity (BTRC) and Tayside Tissue Bank all supported the study.