“X-Men” actress and breast cancer survivor Olivia Munn, 46, knows firsthand what cancer research can make possible. Now she’s thinking about what it could mean for the next generation, including her daughter.

“I have endless gratitude for all of the medical advances that have brought me this far, and I feel so much hope for how much further we can go,” Munn, 45, wrote in a recent social media post.

Read More

 

View this post on Instagram

 

A post shared by o l i v i a (@oliviamunn)

“I hold onto the promise of all it might mean for my daughter’s generation and for all the girls who will grow up in a world shaped by what we do today.”

Munn shared the message while praising a woman named Sara Nicole Vintage, who uses her love of vintage fashion to raise money for cancer research.

Munn’s own breast cancer was found after her doctor calculated her Breast Cancer Risk Assessment Score, and a biopsy revealed an aggressive cancer in both breasts.

“I wouldn’t have found my cancer for another year – at my next scheduled mammogram – except that my OBGYN…decided to calculate my Breast Cancer Risk Assessment Score. The fact that she did save my life,” Munn said in an Instagram post.

Munn’s double mastectomy in May 2023 was the first of five surgeries, and she has since been on endocrine therapy, a treatment she has pointed to as a product of research funding.

Munn explains that her cancer type — hormone‑receptor–positive breast cancer — forced her into a treatment plan centered on shutting down hormone production throughout her body.

 

When a tumor is “hormone receptor-positive,” it means tests reveal the cancer is positive for either the estrogen and/or progesterone receptor. Cancers of this type need estrogen and/or progesterone to grow.

“When you have hormonal breast cancer, your cancer is feeding on hormones and estrogen, and if you do a mastectomy, any little cell left in your body — we need to starve it out. So, let’s shut down the hormone production in your ovaries, and let’s also shut down the testosterone in your body that turns into estrogen,” Munn explained on the “Allure Perspectives” podcast.

For many women, this approach is lifesaving, but for Munn, it came with consequences she describes as “extremely debilitating.”

Lupron and the Reality of Medically Induced Menopause

Munn was prescribed Lupron (leuprorelin), a type of hormone therapy for breast cancer. It acts as an ovarian suppression drug that stops the ovaries from making the hormone estrogen.

Munn says the side effects were overwhelming.

Some known side effects of Lupron may include tiredness or fatigue, hot flashes, spotting, and muscle or joint pain.

“I couldn’t get out of bed, and if I did get out of bed, I’d get something to drink and get right back in it, and I had a small baby, and it was extremely difficult.”

She calls Lupron “extremely debilitating,” describing a level of exhaustion that made daily life nearly impossible — especially while caring for her young child.

Advocating for Herself and Choosing Surgery Over Medication

Munn says her doctors were excellent, but she learned quickly that she had to ask hard questions and push for clarity.

“I had tremendous doctors, and it’s all about asking the right questions and advocating for yourself.”

After her double mastectomy (removal of both breasts), she had already frozen her eggs — a step she took in case she experienced future fertility challenges. Her oncologist tried to preserve her fertility for as long as possible, but Munn felt strongly that she could not continue the hormonal medication.

She told her doctor she wanted an ovariectomy — the removal of her ovaries — to avoid the medication that was draining her physically and emotionally.

Her doctor’s response changed everything:

“My doctor replied, ‘You don’t have to take this one,’ which was a big decision.”

That opened the door for Munn to choose surgery instead of continuing Lupron.

Olivia’s Breast Cancer Diagnosis Despite a ‘Clear’ Mammogram

Munn learned she had an aggressive form of cancer in both of her breasts after receiving a breast cancer risk assessment. She credits the cancer risk assessment for saving her life. The diagnosis was stunning because she had recently received a clear mammogram.

The Breast Cancer Risk Assessment Tool, also called the Gail Model, allows doctors to estimate a woman’s risk of developing invasive breast cancer over the next five years.

Munn says that since going public with her cancer journey, she continues to be approached by other women who are now asking their doctors about the cancer risk assessment since learning of Munn’s, including a young mother of three.

“Every time I go out, there’s at least one person…there was this woman who’s young. She has three kids, and she says because of my story, she went out and took the test and learned she has stage 0 breast cancer,” Munn explained in an Instagram story.

“We both had this moment. I know what you’re going through, but we’re so excited that you found it early,” Munn continued.

“It’s hard to explain knowing that this diagnosis that put so much fear into me has been able to be turned into something that’s saving people’s lives,” Munn told “Meet the Press” host Kristen Welker.

Since Munn shared her story publicly, the National Cancer Institute attributes an uptick in women inquiring about a cancer risk assessment to the “X-Men” actress.

How Munn Was Introduced to the Breast Cancer Risk Assessment

The Breast Cancer Risk Assessment she credits for catching her breast cancer is a “statistical model that allows healthcare professionals to calculate the probability of a woman developing breast cancer over the course of their lifetime,” Dr. Ruth Oratz, breast medical oncologist, NYU Langone Health’s Perlmutter Cancer Center; clinical professor of medicine, NYU Grossman School of Medicine, tells SurvivorNet.

In 2024, she wanted to be proactive about her health and underwent genetic testing.

Genetic tests can be as simple as a saliva swab or a blood sample. The results help your care team determine if you have a specific mutation that puts you at higher risk for cancer. The results help doctors tailor treatment and are helpful for breast cancer patients.

“I tested negative for all (different cancer genes), including BRCA,” Munn said.

The BRCA1 and BRCA2 gene mutations are among the most important genes to look for in breast cancer. Together, they are responsible for about half of all hereditary breast cancers. These genes prevent cells from dividing haphazardly and uncontrollably in a person without mutations. Mutations prevent these genes from doing their job and can allow unchecked growth of breast, ovarian, and other tissues.

However, two months after undergoing genetic testing, Munn was diagnosed with Luminal B breast cancer in both of her breasts.

According to research in “Breast Cancer,” luminal B tumors are of a “higher grade” and tend to have a worse prognosis. This type of breast cancer is estrogen-positive (ER), meaning the hormone estrogen fuels it. It can also be progesterone (PR) negative, meaning it is not fueled by progesterone. This type of breast cancer also tends to have a higher expression of the Ki-67 protein, making it grow quickly. Hormonal therapy and chemotherapy are often used to treat this type of cancer.

Luminal is one of several types and is distinguished by its molecular makeup. Other types of breast cancer include:

• Luminal A breast cancer
• Luminal B breast cancer
• Luminal B-like breast cancer
• HER2-enriched breast cancer
• Triple-negative or basal-like breast cancer

Each type has a specific, individualized molecular structure. The different types of molecular structure of breast cancer may inform the treatment path.

Munn’s Hormone Therapy

For many women diagnosed with breast cancer, the disease is fueled by hormones—specifically estrogen or progesterone. These are known as hormone receptor-positive cancers, and they represent the most common subtype of breast cancer.

“For women who have hormone-positive breast cancer, it means that they have a cancer that needs estrogen to grow,” Dr. Elizabeth Comen, medical oncologist at Memorial Sloan Kettering Cancer Center, explained to SurvivorNet.

WATCH: Understanding Hormone Therapy

Hormone therapy is designed to block or lower the hormones that help cancer cells grow. It’s a cornerstone of treatment for hormone receptor-positive breast cancer, and it plays a vital role in both treatment and prevention.

“Endocrine therapy has significant benefits in reducing the risk of breast cancer recurrence and improving breast cancer survival,” says Dr. Eleonora Teplinsky, head of Breast Medical Oncology at Valley Health System.

These therapies work in two main ways:

• Lowering estrogen levels in the body
• Blocking estrogen receptors on cancer cells so the hormone can’t fuel tumor growth

WATCH: Hormone Therapies for Breast Cancer: Aromatase Inhibitor

Types of Hormone Therapy

One widely used drug is Tamoxifen, which blocks estrogen’s ability to bind to cancer cells. It’s used not only to treat breast cancer but also to help prevent it in women with a strong family history or other risk factors.

Another class of drugs, called aromatase inhibitors, works by stopping the body from producing estrogen altogether. These are typically prescribed to postmenopausal women and include:

• Anastrozole (Arimidex)
• Letrozole (Femara)
• Exemestane (Aromasin)

All are taken as daily pills and have been shown to slow or stop the growth of estrogen-sensitive tumors.

Hormone Therapy Side Effects Can Mimic Menopause

As Munn hinted at, hormone therapy comes with side effects, and one of them can mimic menopause.

Depending on the endocrine or hormone medication, each one may have its own side effects. Typical side effects for certain types of hormone therapy drugs may include:

• Bone pain
• Joint pain
• Loss of appetite
• Nausea and/or vomiting
• Fatigue
• Constipation

What To Ask Your Doctor

If you have been diagnosed with breast cancer, you may have questions about keeping your strength through treatment. Here are a few questions to help you begin the conversation with your doctor:

• What treatment will I be receiving?
• What side effects are associated with this treatment?
• Are there steps I can take daily to help minimize these side effects?
• What physical activity routine do you recommend for me during treatment?
• Do you have recommendations for someone who doesn’t particularly enjoy exercise?
• Can you recommend a dietitian who can help me with healthy eating tips and weight maintenance?
• I’ve been having trouble sleeping. Do you have any treatment recommendations

Learn more about SurvivorNet's rigorous medical review process.

---