Researchers from Johns Hopkins University School of Medicine (MD, USA) have reported findings that suggest a simple blood test based on the detection of tiny epigenetic alterations could detect early signs of pancreatic cancer. At present the disease is usually only discovered after it has spread to other parts of the body, resulting in a high mortality rate with an overall 5-year survival rate of less than 5%.
The team identified two genes, BNC1 and ADAMTS1, which were detectable in 81% of blood samples from 42 individuals with early-stage pancreatic cancer, but not in patients without the disease or with a history of pancreatitis – a risk factor for pancreatic cancer. Promoter DNA methylation of BNC1 and ADAMTS1 was found to occur in pancreatic cancer cells, leading to gene silencing and the down-regulation of a protein, the role of which is not well understood. The researchers used a nanoparticle-enabled methylation on beads technology to assay the promoter methylation status of these genes in circulating DNA from patient serum, and reported this as a promising strategy for early detection of pancreatic cancer.
Although pancreatic cancer is the fourth leading cause of cancer deaths, there is no reliable modality for its early detection, and rates of survival have shown little improvement over the last three decades. Nita Ahuja, an Associate Professor of surgery, ongology and urology at the Johns Hopkins University School of Medicine, and leader of the study commented, “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. 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 stated that as opposed to being a means of screening the general population, the blood test would be best used in individuals at high risk for developing pancreatic cancer (e.g., those with a family history of the cancer, a previous case of pancreatitis or long-term smokers).
If confirmed, the findings of the research could contribute to reducing mortality from pancreatic cancer. Radiation and chemotherapy have not been very effective against it, and surgery is currently the best chance for survival. Theoretically, the surgery should have a higher chance of success if the cancer is detected at an earlier stage and is therefore smaller in size.
Encouraged by the preliminary results, the team aims to duplicate them in a larger sample of tumors. Ahuja added that she hopes further research will also help to refine the test by increasing both its sensitivity and specificity.
Sources: Yi JM, Guzzetta AA, Bailey VJ et al. Novel methylation biomarker panel for the early detection of pancreatic cancer. Clin Cancer Res. doi: 10.1158/1078-0432.CCR-12-3224 (2013) (Epub ahead of print); A simple blood test may catch early pancreatic cancer.