NEW YORK – The National Comprehensive Cancer Network has updated its guidelines for genetic testing to assess the risk of breast, ovarian and pancreatic cancer.
"These NCCN guidelines still have a strong focus on BRCA1 and [BRCA]2 mutations, but also now include other high- and moderate-penetrance genes associated with breast, ovarian, and pancreatic cancer," Mary Daly from Fox Chase Cancer Center and the chair of the guidelines panel said in a statement.
The NCCN recommends genetic testing for all pancreatic cancer patients, but now, updated criteria include greater recognition of genetic risks associated with pancreatic cancer, and mention the cancer in the guideline title. The update includes more information on the genes associated with pancreatic cancer and what screening or management approaches clinicians should take if individuals have pathogenic or likely pathogenic mutations in these genes.
The pancreatic cancer-linked genes included in the guidelines are ATM, BRCA1/2, CDKN2A, MSH2, MLH1, MSH6, EPCAM, PALB2, STK11, and TP53. Recent studies have shown that between 4 percent and 10 percent of individuals with pancreatic cancer have inherited genetic risk mutations.
Data from these studies "have, surprisingly, shown that classic 'high-risk' features of inherited cancer risk (e.g. young age at diagnosis, strong family histories of cancer) are often absent in individuals with pancreatic cancer who carry these mutations," Matthew Yurgelun from Dana-Farber/Brigham and Women’s Cancer Center, and a member of the NCCN guidelines panel, said in a statement.
"Based off of these data, there is now a compelling reason for all individuals with pancreatic cancer to be offered genetic counseling and germline testing for such variants — particularly given the possibility that their at-risk family members could greatly benefit from known, effective cancer risk-reducing interventions (e.g. surgical removal of the ovaries for female BRCA1/2 mutation carriers)," Yurgelun added.
With regard to individuals of Ashkenazi Jewish descent, the NCCN has been recommending genetic testing for those with breast cancer or prostate cancer. In the updated version, the NCCN now recommends that individuals with Ashkenazi Jewish ancestry, regardless of their familial cancer history, may be tested within research studies for the three cancer-linked founder mutations in BRCA1/2 that show up in this population at increased rates. For those that cannot access a study, they can receive commercial testing with appropriate pre- and post-test counseling and follow-up management. "Testing should not be offered outside of a medical framework or clinical trial," the group said.
The guidelines are now organized by disease and syndrome type, and have streamlined information on what steps individuals who meet testing criteria should take. The NCCN panel also notes that genetic mutations can influence cancer treatment, and state that testing may be clinically indicated if it helps guide systemic therapy decisions.
In this update, the NCCN experts also took the opportunity to continue to caution about the growing popularity of direct-to-consumer genetic testing, its limitations, and the potential need for confirmatory testing. "More and more patients are presenting to clinic[s] having already had themselves tested through direct-to-consumer labs," Robert Pilarski from the Ohio State University Comprehensive Cancer Center and vice-chair of the guidelines panel said in a statement. "Providers need to be aware that the tests offered by many of these labs are not equivalent to traditional genetic testing, and the results may need to be confirmed in another laboratory before being used for clinical care."