Scientists develop new blood test to detect, locate cancer early

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New York: Scientists have developed a new method of novel blood test which can easily detect the deadly disease cancer and also locate where the tumour is growing in the body.

This new method is an advance way to eliminate the need for invasive surgical procedures like biopsies.

Cancer blood tests work by screening for DNA released by dying tumour cells and detect traces of tumour DNA in the blood of cancer patients.

However, it does not indicate where the tumour resides in the body.

Kun Zhang, professor at the University of California-San Diego in the US said, "Knowing the tumour's location is critical for effective early detection".

When a tumour starts to take over a part of the body, it competes with normal cells for nutrients and space, killing them off in the process.

As normal cells die, they release their DNA into the bloodstream, and that DNA could be used to identify the affected tissue, the researchers said.

The new blood test screens for a particular DNA signature called CpG methylation haplotypes.

Each tissue in the body can be identified by its unique signature of methylation haplotypes.

If we integrate both cancer cell and other cells signals we could actually determine the presence or absence of a tumour, and where it is growing, Zhang explained.

For the findings, scientists put together a database of the complete CpG methylation patterns of 10 different normal tissues -- liver, intestine, colon, lung, brain, kidney, pancreas, spleen, stomach and blood.

They also analysed tumour samples and blood samples from cancer patients and looked for signals of the cancer markers and the tissue-specific methylation patterns.

The test works like a dual authentication process -- the combination of both signals above a statistical cutoff -- is required to assign a positive match, the researchers noted.

The study was published in the journal Nature Genetics.

(With IANS inputs)