Genetic Testing in Ovarian Cancer

This article is for people who are living with ovarian cancer and their caregivers or anyone who wants to learn more about genetic testing in ovarian cancer. The goal of this activity is to help you talk to your doctor about genetic testing in ovarian cancer.

You will learn about:

• What ovarian cancer is

• What gene mutations are and how they may lead to cancer

• Important gene mutations in ovarian cancer

• What genetic testing is and how it is used in ovarian cancer

• Talking to your doctor and healthcare team about genetic testing and questions you can ask

Ovarian cancer happens when cells in your ovaries start growing out of control and form a tumor. The ovaries are 2 small, oval-shaped organs on either side of your uterus. They make and store your eggs and make hormones that control the release of your eggs (ovulation) and your periods (menstrual cycles).

Ovarian cancer is sometimes used to refer to cancers in the fallopian tubes and the peritoneum. The fallopian tubes are thin tubes that carry eggs from your ovaries to your uterus. The peritoneum is tissue that lines the outside of the organs in your belly (abdomen).

Every cell in your body contains genes. Genes are made of short pieces of DNA, which are like instruction books that tell your genes how to make proteins. Proteins control how your cells work and grow.

You have thousands of different genes, and each gene has 2 copies, with 1 copy inherited or passed down from each of your biological parents. Every known gene has a scientific name and a nickname made of letters and sometimes numbers.

A gene mutation is a change to a gene's DNA that causes it to stop making a certain protein or to make a protein that doesn't work right. Gene mutations can be inherited (passed down from a parent) or acquired (happen over time).

Inherited mutations are found in all your cells before you're born and can be passed down to your children. Acquired mutations happen later and can't be passed down to your children. They may happen when a cell makes a mistake while copying its DNA to make a new cell or has damage to its DNA that it can't repair.

Inherited mutations are also called germline mutations, and acquired mutations are called somatic mutations.

Ovarian cancer can start when a gene mutation makes a faulty protein that causes a cell in your ovaries to make new cells faster than normal. These new cells will have the same mutation and will keep growing until they form a cancerous tumor.

It usually takes more than 1 gene mutation to cause cancer. Having mutations that keep cells from fixing DNA damage can make cancer more likely.

Genetic testing is the only way to find out if you have gene mutations that can cause ovarian cancer. Testing is done by looking at tumor cells collected during surgery or at a sample of your blood or saliva (spit).

Tumor testing gives the most information about gene mutations because it can find inherited and acquired mutations. Saliva or blood genetic testing can only find inherited mutations.

Your doctor may refer you to a genetic counselor to learn about your choices for genetic testing, why genetic testing is important, and what the results could mean for you and your family.

People who have ovarian cancer are often tested for mutations in their BRCA1 and BRCA2 genes. These genes normally make proteins used to repair DNA, which helps protect against cancer. Mutations that keep BRCA1 or BRCA2 from making these proteins can lead to certain cancers.

BRCA1 or BRCA2 mutations are inherited or acquired. People who have inherited BRCA1 or BRCA2 mutations may have family members who have a history of ovarian, breast, or prostate cancer.

Your doctor may also want to test for other gene mutations linked to ovarian cancer and for homologous recombination deficiency, or HRD. Having HRD means your tumor's cells have trouble fixing DNA damage.

Results from genetic testing can help tell your doctor how fast your cancer is likely to grow and which treatments may work for you. For example, some ovarian cancer medicines may work better in tumors with or without certain gene mutations.

If you have an inherited gene mutation, your parents, brothers, sisters, or children could have the same mutation. Your doctor or genetic counselor may recommend telling them about your test results in case they want to get genetic testing. Not everyone who has a genetic mutation will develop cancer, but knowing if you have one can be helpful.

After a few weeks, your genetic testing results should be ready for your doctor or genetic counselor to review with you. Results can be negative, positive, or uncertain.

Negative results mean testing didn't show any inherited or acquired mutations known to cause ovarian cancer.

Positive results can mean testing found:

• One or more inherited (germline) mutations

• One or more acquired (somatic) mutations

• Inherited and acquired mutations

• HRD in your tumor

Sometimes results are uncertain, which means they found mutations other than the ones commonly linked to ovarian cancer. If your results were negative or uncertain, your doctor may recommend more tests.

Questions you can ask your doctor and healthcare team about genetic testing in ovarian cancer include:

• Do I need genetic testing?

• How is testing done and how long does it take to get results?

• What will a positive or negative result mean for me and my family?

• What if the results come back as uncertain?

Congratulations!

You have successfully completed the program Genetic Testing in Ovarian Cancer.

View Additional Materials on this topic that you may find useful:

Cancer

Ovarian Cancer

The Genetics of Cancer

Genetic Testing for Breast and Ovarian Cancer

The BRCA1 and BRCA2 Genes

BRCA1 and BRCA2 Gene Testing

Homologous Recombination Repair