The Role Family History Plays in Your Cancer Risk

Cancer is a widespread disease that impacts nearly every family. The American Cancer Society estimates there were 1.9 million new cases and more than 600,000 cancer deaths in 2021.

If someone in your family has had cancer, you may wonder if you are also at risk. According to Loyola Medicine certified genetic counselor, Anastasia Kathrens-Gallardo, MS, it depends on many factors.

“Most of the time, cancer occurs due to some combination of random DNA changes, environmental factors and lifestyle choices,” says Kathrens-Gallardo.

“Only about 5% to 10% of all cancers have a hereditary cause, but that can be higher for some cancer types.”

What is Hereditary Cancer?

Hereditary cancer occurs when a parent passes an abnormal gene to their child through a sperm or egg cell. Genes are stretches of DNA that play a specific role in cellular function. When the gene is defective, it can lead to cancer.

Cancers that are not hereditary also involve genetic changes (mutations). But they do not affect the sperm and egg cells and do not pass from parent to child.

What are the Types of Inherited Cancer?

Many types of cancers can be hereditary. Some types of cancer, like ovarian cancer, may be more likely to have a hereditary component. Kathrens-Gallardo says about 20% of ovarian cancers are associated with inherited gene changes.

Other common cancers that may have a hereditary cause include:

• Breast
• Colon or colorectal
• Endometrial (uterine)
• Pancreatic
• Melanoma or other skin cancers
• Prostate
• Stomach

A person with an inherited gene change may be at risk of developing multiple types of cancers. For example, people with Lynch syndrome have up to a 60% risk of developing colorectal cancer over their lifetime. They also have an elevated risk of many other cancer types, such as endometrial (uterine), ovarian, stomach and others.

When is Genetic Testing Recommended?

When reviewing a patient’s family history to determine if genetic testing is appropriate, Kathrens-Gallardo looks for:

• A family member who was diagnosed with cancer before age 50 (especially breast, colon or endometrial).
• A relative who has had multiple diagnoses of cancer. This might include separate incidences of cancer in both breasts or two unrelated cancers in different locations.
• Multiple people on the same side of the family with the same type of cancer (usually three or more).
• Someone in the family with a rare type of cancer, such as male breast cancer or pheochromocytoma of the adrenal gland.

Anyone with Jewish ancestry should also consider genetic testing, according to Kathrens-Gallardo. About two-thirds of Jewish people in the U.S. have Ashkenazi heritage.

This group is more likely to carry mutations in the BRCA1 and BRCA2 genes which significantly increase the risk of breast, ovarian, prostate and pancreatic cancer.

What are the Benefits and Limitations of Genetic Testing?

As a genetic counselor, Kathrens-Gallardo discusses the benefits and risks of genetic testing with each patient. “One of my jobs is to educate patients about the test and whether it makes sense for them,” she says.

“Genetic testing can give patients important information about their chances of developing cancer in the future. But it also has some limitations.”

The main benefits of genetic testing are:

• You will have a better understanding of your cancer risk.
• You can develop a plan to help prevent cancer or detect it early.
• Your family can also receive genetic testing and guidance about prevention and early detection.

The drawbacks of receiving a genetic test include:

• A negative test result doesn’t necessarily mean you are not at risk. Your test will look for known genes, but there may be others that scientists have not discovered yet.
• A positive test may impact your ability to purchase life insurance, if you don’t already have a policy.
• You may experience anxiety or psychological distress if your test is positive. Loyola offers psychology services to help people cope with their test results.

What is the Process for Genetic Testing?

Currently, there are about 90 known genes that cause hereditary cancer. Kathrens-Gallardo says the number of genes associated with each type of cancer varies.

“If a person’s family history indicates a risk for breast cancer, at minimum, I order a panel which includes at least eight hereditary breast cancer genes,” she says.

“In some cases, we may offer testing for additional cancer risk genes. The most comprehensive panel we offer can test for up to 84 hereditary cancer genes."

The actual test is quick and painless. Most people receive a blood draw, but saliva testing is also available. The laboratory analysis usually takes about two to three weeks.

After, your genetic counselor will call you to explain what your result means and discuss your next steps.

In most cases, the test costs about $250 but is usually covered by insurance. Our team helps patients check their insurance benefits and apply for financial assistance as needed.

What Happens if you Test Positive?

A positive result means you have a gene that increases your cancer risk. You will receive an estimate which tells you how likely you are to develop certain types of cancer.

Your genetic counselor will explain what this estimate means, help you put it into perspective and will also help you make a plan for cancer screening and prevention.

For example, the average person has a 13% risk of breast cancer over their lifetime. Your test may indicate that your risk is 20%.

Kathrens-Gallardo says people respond differently to these risk estimates. Some patients feel this risk is enormously high, while others are not overly concerned.

After Kathrens-Gallardo talks to the patient, she sends the results to the referring physician who provides further consultation.

Loyola offers two specialized clinics that offer access to genetic counselors and physicians with deep expertise in specific types of cancers.

Patients receive one-on-one guidance to evaluate their test results and make a plan for their future care. These clinics include:

• Cancer Risk Assessment and Prevention Program for women at high risk of hereditary breast and ovarian cancer.
• Gastrointestinal Cancer Risk Assessment Program for people at risk of inherited gastrointestinal cancer, including those with Lynch Syndrome.

A negative (normal) genetic test results is reassuring, but does not rule out cancer risk.

Even patients who test negative receive personalized information about their cancer risk based on their personal and family history. Your genetic counselor may recommend extra or earlier cancer screening based on your family history alone.

How Accurate are At-Home Test Kits for Hereditary Cancer Genes?

You can purchase test kits that identify some genes associated with hereditary cancers. Kathrens-Gallardo advises caution when ordering these kits.

For example, one popular kit will tell you if you have certain BRCA1 or BRCA2 mutations. But it doesn’t test for all the mutations in BRCA1 or BRCA2.

It also doesn't test for the many other genes related to hereditary breast cancer. A negative test result could give you a false sense of security.

Genetic Counseling at Loyola Medicine

Loyola’s genetic counselors bring deep knowledge, experience and compassion to patients who are trying to understand their cancer risk. At Loyola, you’ll also receive:

• Comprehensive support before, during and after your genetic test
• Test results from a reputable laboratory with the highest quality control standards
• Access to cancer experts to help you interpret your test result and decide your next steps

Find out more about Loyola Medicine’s Hereditary Cancer Genetics Evaluation Program

Anastasia Kathrens-Gallardo, is a genetic counselor at Loyola Medicine. She is certified through the American Board of Genetic Counseling. With a focus in cancer genetics screening, Kathrens-Gallardo helps people and their families understand their cancer risk. She’s passionate about making sure patients feel empowered to manage that risk.

Kathrens-Gallardo earned her Master of Science (MS) degree in genetic counseling from Northwestern University’s Feinberg School of Medicine.

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