A blood test can be the key in predicting whether or not melanoma, a type of skin cancer, will relapse, a new study is reporting.

For this study, the team at the Cancer Research U.K. Manchester Institute examined the effectiveness of using a blood test to determine whether or not a patient has developed resistance to a form of treatment or will relapse. The blood test was designed to detect any changes in the DNA that ends up circulating in the bloodstream after being shed by tumors.

The blood test would ideally allow doctors to begin early treatment plans for melanoma patients that could end up extending their lives.

"Being able to spot the first signs of relapse, so we can rapidly decide the best treatment strategy, is an important area for research," lead author, Richard Marais, who is a skin cancer expert at Cancer Research U.K., said in the press release. "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."

The researchers collected blood samples from seven patients with advanced melanoma who were from the Christie NHS Foundation Trust. They found that by tracking the levels of circulating tumor DNA, they could estimate a patient's risk of relapse. The researchers were also able to tie mutations in the NRAS and PI3K genes to the development of tumor drug resistance.

"One of the sinister things about melanoma is that it can lay dormant for years and then suddenly re-emerge, probably as it escapes from the control of the body's immune system," Dr. Peter Johnson, chief clinician at Cancer Research U.K., said. "Being able to track cancers in real time as they evolve following treatment has huge potential for the way we monitor cancers and intervene to stop them growing back."

Marais added, "Our work has identified a way for us to do this but we still need to test the approach in further clinical trials before it reaches patients in the clinic."

The U.S. Centers for Disease Control and Prevention (CDC) reported that 67,753 Americans were diagnosed with skin melanomas with 9,251 deaths in 2012, which was the last time that official statistics were reported.

The study, which was funded by Cancer Research U.K. and the Wellcome Trust, was published in the journal Cancer Discovery.