New Genetic Risk Markers for Pancreatic Cancer Found
Scientists at Dana-Farber Cancer Institute are reporting a new discovery that could help improve screening methods for pancreatic cancer. After conducting a large DNA analysis of people with and without pancreatic cancer, the researchers have identified “several new genetic markers that signal increased risk of developing the highly lethal disease.”
According to the report, which was published online in Nature Genetics, the markers are “variations in the inherited DNA code at particular locations along chromosomes.” The researchers found several variations in DNA code that could influence an individual’s risk for pancreatic cancer.
This study is important because further examination of these DNA variants may help explain on the molecular level why some people are more or less susceptible to pancreatic cancer than the average person, says Brian Wolpin, MD, MPH, first author of the report. He notes that the second important factor to this finding is that it allows for a potential to identify people at increased risk who then might be candidates to undergo MRI or ultrasound scanning to look for early, treatable pancreatic tumors.
“Currently there is no population screening program for pancreatic cancer, which in 80 percent of cases is discovered when it’s too late to allow curative surgery – the cancer has already spread,” Wolpin said.
At this point, the only healthy individuals who get screened for pancreatic cancer are members of “high risk families,” which are those with multiple family members with the disease. “But the field has been struggling to find factors that can identify people at highest risk in the general population, when a strong family history is not present,” Wolpin said.
According to the study:
The study findings represent analyses of DNA from 7,683 patients with pancreatic cancer and 14,397 control patients without this cancer, all of European descent, from the United States, Europe, Canada, and Australia. The scientists used sequencing technology to examine more than 700,000 sites of the genome known to have single nucleotide polymorphisms (SNPs) – differing versions of a single letter of DNA code. These variations can alter the expression of a gene or the content of its message, and the researchers looked for variants that were associated with the risk of having pancreatic cancer. Research of this type is called a genome-wide association study, or GWAS.
Wolpin said the results confirmed the presence of four risk-associated SNPs that had been identified in a previous, smaller GWAS study. In addition, five new risk markers were discovered and a sixth that was of borderline statistical significance.
The risks linked to each SNP or marker were largely independent and additive, so that they may have utility in future attempts to identify individuals in the general population at higher risk for pancreatic cancer. The average lifetime risk of pancreatic cancer is 1.5 percent.
The researchers long-term goal is to create a “risk stratification tool,” something that could be used in doctor’s office to identify individuals who should undergo screening for pancreatic cancer.