Olivia Munn Says Her Mom Has Breast Cancer After Taking Same Test

• Olivia Munn recently shared her mother was also diagnosed with breast cancer.
• The actress has been open about her breast cancer journey and revealed that her mom, Kim Munn, took the same risk assessment test.
• Understanding your family history and other genetic risk factors for breast cancer could be lifesaving.

Olivia Munn has been open about her breast cancer journey since being diagnosed in 2024.

The actress and activist recently shared that her mother, Kim Munn, had also been diagnosed after taking the same risk assessment test she credits with saving her life.

The actress, 45, shared her mother’s diagnosis in an Instagram post on July 9.

“You may know that when I talk about my own battle with cancer I bring up the Lifetime Risk Assessment test that saved my life. I never would’ve predicted it would save my mom’s life as well,” Olivia Munn wrote in the caption.

Olivia Munn was diagnosed with Luminal B breast cancer in both breasts. Because this form of breast cancer can be aggressive, the “Your Friends and Neighbors” star underwent a double mastectomy.

She also had a hysterectomy, which removed her uterus, and a bilateral salpingo-oophorectomy, which is the removal of both ovaries and fallopian tubes. Both procedures can help prevent cancer recurrence.

Around 5–10% of all breast cancer cases are associated with people who have a family history of the disease.

“[Genetic] tests look at the genes you were born with; therefore, one test will be truly lifelong,” said Louise Morrell, MD, medical oncologist and chief medical executive at the Lynn Cancer Institute, part of Baptist Health South Florida.

Healthline recently spoke with Morrell to learn more about genetic risk factors influencing the risk for breast and other types of cancer, and the importance of genetic testing.

This interview has been edited and condensed for clarity and brevity.

Morrell: There are very powerful genetic mutations that cause a high risk of breast cancer, known as BRCA genes. These occur in about 3-4 out of 1,000 [people] and account for only 5% of all breast cancers.

There are also less potent cancer genes that contribute to breast cancer at a much lower rate, which are found in about 10% of the breast cancer population.

Morrell: Generally, the highly potent cancer genes such as BRCA are ‘cancer syndrome’ genes and have an increased risk of multiple cancers, such as the presence of pancreas and prostate cancer, might be a clue that there is a gene that also causes breast and ovarian cancer.

Morrell: Most cancers remain unexplained by family history, but other factors can identify individuals who will benefit from screening tests. More importantly, a negative test for a well-known gene does not rule out the contribution of familial factors.

The most common [misconception] is the belief that we will advise removal of the breasts for [the] BRCA [gene].

While some individuals choose this option, most do not, and are advised that breast cancer screening with MRI can make a difference.