Personalized uterine cancer care: The role of genetic and biomarker testing

Every uterine (endometrial) cancer is unique, and understanding the specifics of your tumor can make a big difference in choosing the right treatment. Your care team uses genetic testing and biomarker testing to gather important information about your cancer. These tests can reveal how the tumor behaves, whether it carries inherited gene changes, and which treatments are most likely to be effective for you. This blog will explain what these tests are, how they’re done, and why they matter in guiding your care based on expert guidelines.

How testing is typically done

Genetic and biomarker testing for uterine (endometrial) cancer is usually done using blood, saliva, or a tissue biopsy, and sometimes a combination of these. A tissue biopsy, taken from the tumor itself, is often used for biomarker testing, while genetic testing is usually done through blood or saliva to look for inherited gene changes. A liquid biopsy can also be used, which looks for tumor DNA circulating in the blood.

How genetic testing differs from biomarker testing

Genetic testing looks for inherited gene changes that you may have received from a parent. While most cases of uterine (endometrial) cancer are not hereditary, testing for Lynch syndrome is important because it can indicate a higher risk for certain cancers, including uterine (endometrial) cancer. Knowing your genetic risk can also be helpful for family members.

Biomarker testing looks for changes that occur in the cancer cells themselves, called somatic mutations. These are not passed down to family members. Biomarker testing is usually done on a tissue biopsy, but a liquid biopsy can be used if a tissue biopsy isn’t possible. The results of biomarker testing can guide treatment decisions and help your care team determine which therapies are likely to work best.

Important biomarkers to assess

The NCCN Guidelines recommend testing all uterine (endometrial) cancers for the following biomarkers:

• POLE mutations: Tumors with POLE mutations often have a high number of mutations, which may make them respond better to certain immunotherapies.
• Mismatch repair deficiency (dMMR): This occurs when the tumor cells can’t properly fix DNA mistakes, which may suggest eligibility for immunotherapy.
• p53 mutations: Abnormalities in p53 are associated with more aggressive disease and can help guide treatment planning.

Other biomarkers can also be assessed, although they are less common:

• NTRK fusions and RET fusions: These gene changes can drive tumor growth and targeted therapies exist that specifically block their effects.
• Tumor mutational burden (TMB): A high number of mutations in the tumor may make it more likely to respond to immunotherapy.
• HER2 expression: HER2-positive tumors may respond to therapies that specifically target the HER2 protein.

For recurrent or advanced uterine (endometrial) cancers, the NCCN Guidelines also recommend hormone receptor testing. This can help your care team understand whether hormonal therapies might be effective as part of your treatment plan.

Moving forward with your care

Genetic and biomarker testing give your care team a detailed roadmap of your diagnosis, helping them choose treatments that are most likely to work for you. These tests can also identify options for clinical trials or targeted therapies that might not otherwise be considered. 

While the results can feel overwhelming at first, understanding the molecular and genetic details of your tumor puts you in a stronger position to make informed decisions about your treatment.

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