Around 10% of pancreatic cancer cases are hereditary or familial. Genetic testing provides insights into inherited predispositions, which can influence personal health management and family planning. This information helps identify those at an increased risk, allowing for more proactive medical approaches.
Why Genetic Testing for Pancreatic Cancer?
Genetic testing for pancreatic cancer aims to identify inherited gene changes, known as germline mutations, passed down through families. This differs from tumor testing, which analyzes mutations present only within the cancer cells themselves and primarily guides treatment decisions for the person with cancer. Discovering an inherited mutation can inform treatment strategies for the affected individual, potentially leading to more personalized care.
Identifying a germline mutation can reveal a predisposition in family members. This knowledge enables at-risk relatives to consider early detection screening programs. Such screenings are designed to find the cancer at an earlier, more treatable stage, which is associated with improved survival outcomes.
Who Should Consider Genetic Testing?
Current guidelines from organizations like the National Comprehensive Cancer Network (NCCN) recommend that any person diagnosed with exocrine pancreatic cancer (adenocarcinoma) undergo genetic counseling and testing, regardless of age or family history. Approximately one in ten individuals with pancreatic cancer will test positive for an inherited mutation.
Genetic counseling and testing are also recommended for individuals with a first-degree relative (parent, sibling, or child) diagnosed with pancreatic cancer at any age. If the person with pancreatic cancer cannot be tested, their first-degree relatives may still proceed. Testing may also be considered for individuals with second-degree relatives (grandparents, aunts, uncles, nieces, or nephews) who have had pancreatic cancer.
Genetic counseling is advised if there’s an inherited genetic syndrome linked to pancreatic cancer in the family, or if multiple family members in the same or consecutive generations have been diagnosed with the disease.
Other indicators include pancreatic cancer occurring in two or more generations on the same side of the family, or an early onset diagnosis, generally before the age of 50. Genetic counseling is also a consideration if an individual has been diagnosed with more than one primary cancer.
Even if previous genetic testing yielded negative results or was conducted before 2014, individuals diagnosed with pancreatic cancer may benefit from additional genetic counseling and expanded testing due to advancements.
Understanding Genetic Test Results and Screening
If a genetic mutation is identified through testing, family members can then consider genetic counseling and testing themselves. The results of genetic testing provide valuable information for establishing personalized screening and surveillance plans. For instance, individuals with specific mutations in genes like BRCA1, BRCA2, or PALB2 are often recommended to begin pancreatic cancer screening at age 50, or 10 years earlier than the youngest relative diagnosed with pancreatic cancer.
For those with Familial Atypical Multiple Mole Melanoma (FAMMM) syndrome, screening might start at age 40, or 10 years earlier than the youngest affected relative. Individuals with Peutz-Jeghers syndrome may begin screening at age 35, or 10 years earlier than the youngest relative with pancreatic cancer. Heterozygotes for an ATM pathogenic variant with a first or second-degree relative diagnosed with pancreatic cancer are advised to start screening at age 50, or 10 years prior to the youngest relative’s diagnosis. Genetic counseling helps interpret these results and discuss the potential benefits and harms of screening, ensuring individuals make informed choices about their health management.