Simple Blood Test May Catch Early Pancreatic Cancer
Disease usually found too late to save lives (October 23)
Reporting on a small preliminary study, Johns Hopkins researchers say a simple blood test based on the detection of tiny epigenetic alterations may reveal the earliest signs of pancreatic cancer, a disease that is nearly always fatal because it isn’t usually discovered until it has spread to other parts of the body.
The findings, if confirmed, could be an important step in reducing mortality from the cancer, which has an overall 5-year survival rate of less than 5% and has seen few improvements in survival over the last three decades.
Researchers were able to identify two genes, BNC1 and ADAMTS1, which together were detectable in 81% of blood samples from 42 people with early-stage pancreatic cancer, but not in samples from patients without the disease or from patients with a history of pancreatitis, a risk factor for pancreatic cancer. In contrast, the commonly used prostate-specific antigen (PSA) test for prostate cancer detects only 20% of those cancers.
The investigators found that, in pancreatic cancer cells, it appears that chemical alterations to BNC1 and ADAMTS1 silence the genes and prevent them from making their protein product. These alterations are caused by the addition of a methyl group to the DNA.
Using nanoparticle magnets, 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.
Specifically, the researchers say they found BNC1 and ADAMTS1 in 97% of tissues from early-stage invasive pancreatic cancers. Surgery is the best chance for survival in pancreatic cancer because radiation and chemotherapy are not effective against it. The smaller the cancer — the earlier it is detected — the more likely it is that surgery will be successful and that the patient will survive.
The investigators note that once BNC1 and ADAMTS1 are identified in a patient’s blood, further tests will be needed to locate the actual tumor.
Source: Johns Hopkins University; October 23, 2013.