Simple blood test may catch early stage pancreatic cancer

Scientists, including one of Indian-origin, have developed a simple blood test to detect the earliest signs of pancreatic cancer.

Pancreatic cancer is nearly always fatal because it isn't usually discovered until it has spread to other parts of the body.

The blood test developed by Johns Hopkins researchers is based on detection of tiny epigenetic alterations.

"We have mammograms to screen for breast cancer and colonoscopies for colon cancer but we have had nothing to help us screen for pancreatic cancer," said Nita Ahuja, an associate professor of surgery, oncology and urology at the Johns Hopkins University School of Medicine and leader of the study.

"While far from perfect, we think we have found an early detection marker for pancreatic cancer that may allow us to locate and attack the disease at a much earlier stage than we usually do," Ahuja said.

For their study, Ahuja and colleagues were able to identify two genes, BNC1 and ADAMTS1, which together were detectable in 81 per cent of blood samples from 42 people with early-stage pancreatic cancer, but not in patients without the disease or in patients with a history of pancreatitis, a risk factor for pancreatic cancer.

By contrast, the commonly used PSA antigen test for prostate cancer only picks up about 20 per cent of prostate cancers.

Researchers found that in pancreatic cancer cells, it appears that chemical alterations to BNC1 and ADAMTS1 - epigenetic modifications that alter the way the genes function without changing the underlying DNA sequence - silence the genes and prevent them from making their protein product, the role of which is not well-understood.

These alterations are caused by the addition of a methyl group to the DNA.

Using a very sensitive method called Methylation on Beads (MOB) developed by Jeff Tza-Huei Wang, a professor at the Whiting School of Engineering at Johns Hopkins, the researchers were able to single out, in the blood, even the smallest strands of DNA of those two genes with their added methyl groups.

The technique uses nanoparticle magnets to latch on to the few molecules being shed by the tumours, which are enough to signal the presence of pancreatic cancer in the body, the study found.

Researchers found BNC1 and ADAMTS1 in 97 per cent of tissues from early-stage invasive pancreatic cancers.

The study was published in the journal Clinical Cancer Research.