Blood test may indicate skin cancer relapse

London: Researchers have found that a blood test may be able to sound early warning bells that patients with advanced melanoma skin cancer are suffering from relapse.

"Being able to spot the first signs of relapse, so we can rapidly decide the best treatment strategy, is an important area for research,” said lead study author Richard Marais, skin cancer expert at Cancer Research UK, a leading cancer charity dedicated to saving lives through research.

"Using our technique we hope that one day we will be able to spot when a patient's disease is coming back at the earliest point and start treatment against this much sooner, hopefully giving patients more time with their loved ones," Marais noted.

The findings were published in the journal Cancer Discovery.

The researchers studied the DNA shed by tumours into the bloodstream -- called circulating tumour DNA -- in blood samples from seven advanced melanoma patients.

In this early work they found they could see whether a patient was relapsing by tracking levels of circulating tumour DNA. 

And they found that new mutations in genes like NRAS and PI3K appeared, possibly causing the relapse by allowing the tumour to become resistant to treatment.

Most melanoma patients respond to treatment at first but their cancer can become resistant within a year. 

It is hoped that these approaches will allow doctors to use circulating tumour DNA to tailor treatment for individual patients to get the best result.