NEW BLOOD TEST THAT COULD DIAGNOSE FIVE DIFFERENT CANCERS

A new blood test that detects five different forms of cancer is one step closer to becoming a reality and could save millions of lives around the world.

The team of scientists developing the new diagnostic tool have branded their discovery of a 'striking DNA signature' in five forms of the disease, an 'important step'.

The signature occurs in colon, lung, breast, stomach and endometrial cancers, researchers at the National Human Genome Research Institute found.

When tumors develop in any of these areas, one specific gene - known as' ZNF154 '- changes its chemical signature.

It raises hopes that a simple blood test to diagnose these, and other forms of the disease, may become a reality in the near future.

Researchers found when a person was suffering cancer, higher amounts of methylation occurred - a process where a gene is switched 'off'.

They describe methylation as controlling the expression of genes 'like a dimmer on a light switch'.

Higher levels of methylation, like that found in some tumors, decreases a gene's activity.

n 2013, Dr Elnitski and her team discovered a methylation signature around the ZNF154 gene in 15 types of tumor, in 13 different organs - and deemed it a possible universal cancer biomarker.

Biomarkers are biological molecules that indicate the presence of disease.

Dr Elnitski's group identified the methylation signature using DNA taken from solid tumors.

 In this new study, the researchers developed a series of steps that uncovered telltale methylation marks in colon, lung, breast, stomach and womb cancers.

They showed that all the tumor types and sub types consistently produced the same methylation mark around the ZNF154 gene.

Scientific director at the NHGRI, Dr Dan Kastner said: 'Finding the methylation signature was an incredibly arduous and valuable process.

'These findings could be an important step in developing a test to identify early cancers through a blood test.' 

Current   blood  tests  for  cancer  are    specific  to  Tumor   type.

  doctors have to first find the tumor, remove a sample of it and determine its genome sequence. 

Once the tumor-specific mutations are known, they can be tracked for appearance in the blood.

Once the tumor-specific mutations are known, they can be tracked for appearance in the blood.

The new blood test offers much more potential.

No prior knowledge of cancer is required - meaning the blood test could be the first test used to diagnose the disease.

It would be less invasive and instrusive than other screening methods like colonoscopies, and mammograms and it could be used to follow individuals at high risk for cancer.

In addition it could be used to monitor the activity of a tumor during treatment.

Once the blood test is developed, studies will be needed to ensure it does not indicate the presence of cancer when the disease is not there, or indeed miss it when it is present.

 Dr Elnitski said: 'We have laid the groundwork for developing a diagnostic test, which offers the hope of catching cancer earlier and dramatically improving the survival rate of people with many types of cancer.'