Is pancreatic cancer hereditary?
Sometimes yes—sometimes no.
A recent study published in JAMA found that just over 5% of patients with pancreatic cancer carried hereditary mutations. In patients with pancreatic cancer who also had a family history of pancreatic cancer, nearly 8% of patients were found to carry hereditary mutations.
Which genes were associated with an increased risk for pancreatic cancer?
- BRCA1 and BRCA2: The BRCA genes are best known for their association with high risks for breast and ovarian cancer, but BRCA2 mutations in particular are also known to be associated with an increased risk for pancreatic cancer. About 2% of patients with pancreatic cancer were found to have mutations in the BRCA2 gene. Less than 1% of patients with pancreatic cancer were found to have mutations in the BRCA1 gene.
- ATM: The ATM gene is often included on hereditary breast cancer panels but is also recognized to be associated with an increased risk for pancreatic cancer. Just over 2% of patients with pancreatic cancer in this study were found to have mutations in the ATM gene.
- MLH1: This is one of several genes associated with Lynch syndrome. Less than 1% of individuals with pancreatic cancer in this study were found to have a mutation in the MLH1 gene.
- CDKN2A: Mutations in this gene are also associated with a high risk for melanoma. Less than 1% of individuals with pancreatic cancer in this study were found to have a mutation in the CDKN2A gene.
Is any of this new?
The reported associations between these genes and an increased risk for pancreatic cancer is not new, but this study does provide further support for these associations, particularly as this is one of the largest case-control studies to date (3,030 patients with pancreatic cancer). Current NCCN Guidelines do recommend consideration of genetic counseling and germline testing for all individuals with pancreatic cancer.
Why does genetic testing related to pancreatic cancer matter?
Identifying a hereditary cancer mutation can help with early detection and, in many cases, prevention of cancer.
Unfortunately, to date there is no routine and effective screening available for pancreatic cancer, although specialized centers may use screening protocols involving ultrasound and/or MRI for certain high risk patients. All six of the genes associated with pancreatic cancer in this study, however, are also associated with increased risks for other cancer for which there are well established interventions to help reduce risk. If you or a family member have pancreatic cancer and a hereditary cancer mutation is found, targeted testing for the identified mutation can also be done for other family members.
Generally, the same hereditary cancer mutation identified in the blood will also be found in the tumor. In some cases, these mutations can be helpful therapeutic targets and therefore may impact treatment options that a medical oncologist would discuss with you.
Genetics + Environment + Chance
As with many health conditions, cancer can be thought of as a product of Genetics + Environment + Chance. We do have some control over some of the these environmental risk factors. Smoking, type 2 diabetes, and obesity are all important risk factors for pancreatic cancer. There are of course, in turn, genetic risk factors for type 2 diabetes and obesity—but diet and exercise can help to reduce the risk of pancreatic and other cancers.
- If you have a personal or family history of pancreatic cancer, hereditary cancer testing may provide you and family members with valuable information. Take our quiz and we will follow up with you.
- Even if you don’t meet NCCN guidelines for genetic testing, relatively low-cost testing options that are still high quality are available and could be considered.
- Have a few questions? You can schedule a free 10-minute consultation online.
- Do you have a story related to pancreatic cancer in your family and how genetic testing was (or was not) helpful to you? Check out our Patient Stories podcast. We would love to interview you and share your story.
For Healthcare Providers
- If you are caring for patients with a personal or family history of pancreatic cancer, consider referring to genetic counseling and hereditary cancer testing.
- If you are caring for a patient with pancreatic cancer, be sure to ask about a family history of BRCA– and Lynch-related cancers: breast, ovarian, prostate, melanoma, colon, endometrial, stomach.
- If you have a genetic counselor within your hospital or medical practice, reach out to them to talk about when and how to refer patients with pancreatic cancer, and how you can work together better.
- Questions about a specific case? Feel free to email me with questions. I would be happy to discuss.
- Looking for more support for your practice to keep up with all the rapid changes in genetics? Check out the new Grey Genetics support packages to find the option that works best for your practice.
References & Further Reading:
Hu C, Hart S. “Association Between Inherited Germline Mutations in Cancer Predisposition Genes and Risk of Pancreatic Cancer.” JAMA 2018; 319(23) 2401-2409.
Syngal S, Furniss CS. “Germline Genetic Testing for Pancreatic Ductal Adenocarcinoma at Time of Diagnosis.” JAMA 2018; 319(23) 2383-2385.
Jenkins, Kristen. “Genetic Testing in Relatives of Pancreatic Cancer Patients?” Medscape. June 21, 2018.
Wallis, Claudia. “Why Pancreatic Cancer is on the Rise.” Scientific American. April 1, 2018.
related and published after this blog post was written:
Yurgelun, MB, Chittenden, AB. “Germline cancer susceptibility gene variants, somatic second hits, and survival outcomes in patients with resected pancreatic cancer.” Genetics in Medicine, July 2, 2018.