Should you consider genetic testing for cancer?

Your genes are more than just biological blueprints — they’re part of your story. They help shape who you are, from your height and hair color to the traits that make you uniquely you. But did you know your genes also hold clues about your health, including your risk for cancer?

Genetic testing — while not a crystal ball — can provide a window into that risk.

“For a lot of people, genetic testing can bring peace of mind,” says Brynna Morales, MS, LCGC, a board-certified genetic counselor at MultiCare Cancer Institute. “The results can help you make decisions about your health and understand if there’s an increased cancer risk that you could pass on to future generations.”

Find out if cancer genetic testing might be right for you and what to expect from the process.

Why does cancer happen?

Each cell in your body contains genes — a set of instructions that tell cells how to function, including how and when to divide. Cells divide as we grow and age to maintain healthy tissue.

Sometimes when cells divide, changes happen to genes. These changes, called mutations, can cause cells to grow out of control, leading to cancer.

Most cancer-causing mutations happen by chance, or through the natural aging process. Environmental and lifestyle factors, like tobacco use, can also increase the risk of these mutations.

In some cases, people can inherit cancer-causing mutations. These are known as inherited cancer syndromes and can raise the risk of developing certain types of cancer.

“These mutations can be passed down from one generation to the next,” says Morales. “Hereditary cancers consist of about 5-10 percent of all cancers that we know of.”

Common types of hereditary cancers

Genetic testing can determine if you have an inherited cancer risk. There are more than 50 known types of inherited cancer syndromes. Here are the two most common.

Hereditary breast and ovarian cancer syndrome

This cancer syndrome refers to people who carry the BRCA1 and BRCA2 gene mutations, which increase the risk of breast and ovarian cancers.

In general, women have about a 12 percent risk of breast cancer and a 1 percent risk of ovarian cancer in their lifetimes, explains Morales. For women with a BRCA mutation, that risk climbs to more than 50 percent for breast cancer and over 20 percent for ovarian cancer.

Yet it’s a common misconception that these gene mutations only affect women.

“They actually increase the risk of male breast cancer and prostate cancer,” Morales says. “And for all people, BRCA1 and BRCA2 can up the risk of pancreatic cancer and melanoma, an aggressive form of skin cancer.”

Lynch syndrome

Caused by inherited mutations across several genes, Lynch syndrome is the most common inherited cancer syndrome, according to the American Cancer Society. It increases the risk of several types of cancer, including colon and endometrial cancers.

Benefits of genetic testing for cancer

Discovering you have an inherited risk of cancer can be upsetting, so why would you want to pursue genetic testing?

“If you know you have an inherited cancer risk, you can take action to prevent cancer from developing or catch it early when it may be more easily treated,” Morales says.

Let’s say you undergo genetic testing and test positive for an inherited cancer syndrome. Depending on the type and your particular situation, here are potential steps you could take to support your health:

• Make proactive changes to your lifestyle, such as limiting alcohol consumption or eating a more nutritious diet, to lower your risk of cancer
• Increase surveillance by starting cancer screenings at a younger age or getting more frequent screenings
• Consider undergoing risk-reducing procedures

If you’ve already been diagnosed with cancer, learning about an inherited gene mutation can inform your course of treatment and strategies for preventing recurrence.

It’s also important to remember that if you undergo genetic testing, you may not be the only one to benefit.

“Finding out you have an inherited cancer risk and sharing those results with family members may empower them to get tested — and take steps to better manage their risk,” Morales says.

When to consider genetic testing for cancer

MultiCare’s cancer genetics team will see anyone, by referral, for a hereditary cancer risk assessment — whether or not you have a personal or family history with cancer.

Your doctor or other health care provider may recommend cancer genetic testing if you:

• Were diagnosed with cancer before the age of 50, or someone in your family was diagnosed before this age
• Have been diagnosed with a rare cancer, such as pancreatic or ovarian cancer
• Have multiple family members with the same type of cancer
• Have a relative with more than one type of cancer
• Have a family member with an inherited cancer syndrome

How does cancer genetic testing work?

Genetic testing for cancer usually starts with a referral from your primary care doctor, OB/GYN or other health care provider. From there, you’ll meet with a genetic counselor who will ask about your personal health history and your family’s cancer history, going back about three generations.

“Sometimes all people know is family lore about a relative’s condition,” Morales says. “But even that word of mouth is helpful when we’re trying to assess predisposition for cancer.”

Even if you don’t know your family’s health history, you can still pursue genetic testing.

“Finding out you have an inherited cancer risk and sharing those results with family members may empower them to get tested — and take steps to better manage their risk,”

After your initial appointment, your genetic counselor will determine if you meet criteria for genetic testing and explain your options. Many insurance plans cover genetic testing, but it’s a good idea to verify with your carrier. You can also choose to self-pay at a cost of about $250.

“Genetic counselors are trained in both the science of genetics and the psychosocial aspects of this experience,” Morales says. “Testing can support peace of mind, and it can also bring anxiety. We help people navigate these feelings and consider the risks and benefits, so they can make the right choice for them.”

Testing involves a simple blood draw or cheek swab. Once the lab has processed your results, your genetic counselor will contact you to review them and discuss next steps.

What do cancer genetic testing results mean?

Test results may come back positive, negative or uncertain. An uncertain result means that a genetic mutation was identified but its significance is unknown.

“We treat an uncertain result as a negative result because most of the time these changes don’t end up being cause for concern,” Morales says.

Also, while cancer genetic tests are useful tools, they don’t capture the full story of your cancer risk.

“Even if you have an inherited mutation, it doesn’t mean you’ll definitely go on to develop cancer,” Morales said. “On the other hand — if you test negative — it doesn’t mean that you’ll never develop cancer, or that you don’t have increased risk based on other factors in your life.”