Ask the Expert: Is Cancer in My Genes?

Odds are that someone in your family tree has been diagnosed with cancer. Does this cancer run in your family? Are you and your children at risk?

The risk of developing some cancers can be genetically passed down in DNA. Through genetic testing, you can learn if your genes increase your risk of developing hereditary cancers. The results of these tests do not mean that you will or will not definitively develop cancer of any kind. However, understanding your unique risk can help you and your doctors be proactive about your lifestyle choices, health screenings and testing for other family members. If you ever face a cancer diagnosis, genetic testing can help your doctors determine the most effective course of treatment.

“Genetic testing can provide insight into your health and help identify family members who may be at higher-than-average risk. This information has the potential to save lives,” says Bianca V. Perez, an advanced practice registered nurse (APRN) at Sylvester Comprehensive Cancer Center, part of the University of Miami Health System. “They say knowledge is power, and individuals who understand their risks can make informed decisions about their health care.”

Every day, Perez and her colleagues at Sylvester help patients and their families better understand their genetic cancer risks and take action to help lower that risk, prevent cancer from developing and detect these diseases at their earliest and most treatable stages. Today, as the APRN for the Genetic Predisposition Syndrome (GPS) Clinic, she addresses some of the most common questions and concerns about genetic testing and cancer risk.

Are certain types of cancers more likely to be genetic?

“We know that about 5 to 10% of cancers are due to inherited changes in a cancer predisposition gene. These changes are often referred to as “mutations” and can be passed down from either mother or father,” Perez says.

“There are certain cancers that are more likely to be hereditary, including ovarian and pancreatic cancers. Estimates show that roughly 20% of ovarian cancers are due to inherited changes in certain genes, and about 10% of pancreatic cancers are due to underlying hereditary factors.”

People in my family have had cancer. Should I get genetic testing?

“Individuals with a significant personal or family history of cancer should consider undergoing genetic counseling and testing to better assess their cancer risk,” Perez says.

This includes individuals with a personal or family history including:

• Multiple relatives with the same type of cancer
• Cancers diagnosed at a young age (younger than 50)
• Family members diagnosed with more than one type of primary cancer (such as colon and endometrial cancers)
• Family members diagnosed with cancers associated with hereditary cancer syndromes (such as breast and ovarian cancers)
• Male breast cancer
• A known inherited genetic mutation in a close relative
• Personal or family history of multiple colon polyps

There are many more personal and hereditary circumstances for which genetic testing is recommended.

“Anyone who has survived ovarian or pancreatic cancer, for example, should undergo a type of genetic testing called germline testing, which looks for inherited predispositions to cancer.”
– Bianca Perez, APRN

“If you have been diagnosed with any type of cancer, we recommend discussing the potential benefits of germline testing with your oncologist or a health care provider who specializes in genetics.

“In addition, certain populations may benefit from genetic testing,” she says. “For example, individuals with Ashkenazi Jewish ancestry should consider genetic testing, as they may be at higher risk of having an inherited susceptibility to cancer.

“The best way to determine if a cancer in your family occurred due to an inherited mutation is to undergo genetic testing,” Perez says. “We always recommend testing the family member who has or had a cancer diagnosis because this provides the best chance of identifying a familial mutation. Of course, this is not always feasible. If you feel you may benefit from genetic testing, consider making an appointment with Sylvester’s High-Risk Clinics or the GPS Clinic or with a genetics provider near you.”

How can I document my family history of cancer?

“At our High-Risk and Genetic Predisposition Syndrome Clinics, we go over each patient’s family history and create a three-to-four generational pedigree detailing their family’s cancer history. This can help determine if the patient would benefit from genetic testing,” Perez says.

“Before your consultation, we recommend obtaining the cancer history of your siblings, parents, children, aunts, uncles, cousins and grandparents. If a member of your family has undergone genetic testing, it would also be beneficial to review it with your provider during your pretest genetic counseling visit.”

As an example, let’s say a patient comes into Sylvester’s High-Risk or Genetic Predisposition Syndrome Clinic for a consultation about her hereditary cancer risk.

The patient is a female in her 40s. Her father was diagnosed with prostate cancer in his 70s, and her maternal grandmother died of breast cancer before age 50. What can you do with this information?

“This is a typical case scenario that is seen in our High-Risk Clinic,” Perez says. “While we would continue to obtain details regarding any other cancers in this patient’s family, this information alone would qualify her to undergo genetic testing since she has a second-degree relative with a breast cancer diagnosis before the age of 50.

“If she decides to proceed with testing, we would await the results and use that information (along with other details of her personal history) to calculate a personalized risk assessment to see if she qualifies for supplemental breast cancer screenings.

“If we find that this woman has an inherited mutation in a BRCA1 or BRCA2 gene, and she develops the disease in the future, she may be eligible for selective, targeted therapies that have proven beneficial in the management of breast cancer,” she says. Patients referred for treatment at Sylvester will experience a multidisciplinary approach to their care and will be able to consider preventive surgeries. Perez explains that her team works closely with surgeons and other specialists.

“If this patient’s genetic testing results are negative, a risk assessment should still be performed because she could be considered high-risk based on her family history alone. This information may also impact the screening recommendations for her children once they reach adulthood.”

Germline testing revealed that I carry a genetic mutation for cancer. What can I do about this?

“Lifestyle changes can absolutely play a role in reducing your risk for developing cancer,” Perez says. “It’s important to note that not everyone who inherits a susceptibility to a particular cancer will go on to develop the disease. We are still learning why some individuals develop cancer and others don’t.”

Here’s what has been shown to be beneficial in reducing cancer risk:

• being physically active
• eating a balanced diet
• maintaining a healthy weight
• avoiding tobacco use
• limited or avoiding alcohol consumption

“At our clinics, we offer courtesy visits with a health coach so patients can have a detailed discussion regarding lifestyle modifications at no cost of their own,” she says.

Scenario: I’ve lost family members to cancer. I have the gene for it, and now I’m afraid.

“It’s normal to experience some anxiety when you are found to have an inherited susceptibility to cancer,” Perez says. “You may experience feelings of uncertainty and fear of the future. That’s why it’s essential to have a supportive health care team to help you navigate through these feelings and provide detailed risk assessments.

“In addition, it’s important to emphasize that there’s no guarantee that you will develop cancer. However, understanding your individual risk through genetic testing allows for a more personalized cancer screening plan and an overall proactive approach to your health care,” she says. “You can benefit from options such as increased surveillance, risk-reducing measures and earlier intervention ¾ all of which play a role in improved health outcomes.

“As science continues to evolve, we can  expect to have even more options in treatment and prevention strategies to reduce the cancer burden in our community.”

Dana Kantrowitz is a regular contributor to UHealth’s news service.

Tags: Bianca Perez, cancer care in Miami, cancer risk, genetic predisposition, Sylvester Comprehensive Cancer Center