Editor’s note: Knowledge is power, but keeping up with all the different types of genetic and molecular tests and profiling can be daunting for even the savviest patients and their caregivers. Here, we break down the different types of analyses that patients can opt to undergo, and how the information gained can benefit the patients and their family members, as well as provide valuable information to support people who will be diagnosed in the future.
To understand the types of testing that are available to pancreatic cancer patients, it’s important to first know what the tests measure. Most cases of cancer arise due to mutations, or mistakes, in genes, which are segments of DNA.
For pancreatic cancer, around 5 to 10 percent of cases are thought to be hereditary, which means a risk for the disease runs in the family. When a mutation occurs in a person’s gamete (egg or sperm), it is referred to as a germline mutation. Germline mutations can be passed down from parents to children and occur in every cell of an affected person’s body.
Germline mutations can be detected through genetic testing. Because the alterations to a person’s DNA are consistent throughout their whole body, this analysis is typically done on a sample of blood or saliva.
People who are considered at high risk for pancreatic cancer due to a strong family history of the disease, or who are concerned about a potential inherited risk, can undergo genetic testing. It’s important to speak with your doctor and/or a genetic counselor to select the best tests and next steps that are right for you.
Recent data suggest that individuals who have already been diagnosed with pancreatic cancer, regardless of their family history, should undergo germline genetic testing as well. This recommendation stems from an unexpected finding that germline mutations were found at a similar rate in pancreatic cancer patients whether they did or did not have a family or personal history of pancreatic cancer. These mutations are still relatively rare, however, and found in about 5 to 8 percent of all pancreatic cancer patients.
Another type of mutation, called a somatic mutation, occurs after somebody is born and can happen in any cell of the body, except for gametes (egg or sperm). Somatic mutations can be caused by carcinogens like cigarette smoke or UV rays from the sun, or can just occur randomly, and are not passed down through a family.
Somatic mutations that contribute to a patient’s pancreatic cancer can be identified through molecular profiling of a piece of tissue obtained from their tumor. Molecular profiling allows doctors to pinpoint the exact biological changes that occurred to make a healthy cell in the pancreas turn cancerous.
This is also sometimes called tumor testing, genomic testing or biomarker testing. This information can then help guide personalized treatment decisions for the patient that may not have been considered otherwise.
PanCAN’s Know Your Tumor® precision medicine service can provide patients and their healthcare teams with information about both germline and somatic mutations.
Through molecular profiling of the tumor tissue, recently published data showed that about half of patients who received Know Your Tumor reports had an alteration in their tumor that could influence their treatment decisions. And more than a quarter of patients had a “highly actionable” mutation, which means there’s scientific and clinical evidence of a treatment being effective in pancreatic or other cancer patients with that same alteration.
In addition to tumor tissue analysis, patients can also opt for germline testing through Know Your Tumor. This information can be useful to determine whether the patient’s children or other relatives should be tested to see if they may be at an elevated risk for the disease.
“Since every pancreatic tumor is different, we at PanCAN strongly recommend molecular profiling of your tumor to help determine the best treatment options,” said Lynn Matrisian, PhD, MBA, chief science officer at PanCAN.
“We’ve had patients undergo our program and discover extremely rare – but very actionable – alterations that they never would have known about otherwise. And those patients are still doing very well because of treatments targeted to their alterations.”
Matrisian added, “It’s also important for patients to know if they have any genetic alterations within their germlines, which can impact their future risk of other cancers and can have implications for their family members’ cancer risk.”