Olivia Munn Says Breast Cancer Would Have Been ‘Climbing An Iceberg’ Without John Mulaney

Olivia Munn Says Breast Cancer Would Have Been ‘Climbing An Iceberg’ Without John Mulaney
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Olivia Munn, 43, is opening up about her "terrifying" breast cancer diagnosis.

On April 17, the actress shared more about learning that she had luminal B cancer—a fast-moving, aggressive cancer—in both breasts. Within 30 days of her diagnosis, she underwent a lymph node dissection, a nipple delay procedure, and a double mastectomy. (Months later, she underwent a reconstructive surgery.) She's also undergoing hormone suppression therapy to reduce her chances of the cancer returning, which has put her into "medically induced menopause."

“There’s so much information, and you’re making these huge decisions for the rest of your life,” Olivia told People. “I really tried to be prepared, but the truth is that nothing could prepare me for what I would feel like, what it would look like and how I would handle it emotionally. It was a lot tougher than I expected."

In March, the actress first announced in an Instagram post that she was diagnosed with breast cancer in April 2023.

"I was diagnosed with breast cancer," she captioned her post. "I hope by sharing this it will help others find comfort, inspiration and support on their own journey."

She then detailed how she was diagnosed, what her treatment has been like, and how her partner John Mulaney has supported her through it all.

Meet the expert: Jason Aboudi Mouabbi, MD, is a medical oncologist MD Anderson Cancer Center, Houston.

Here's everything to know about Olivia's breast cancer journey so far—and how her advice can help others, according to a medical oncologist.

Olivia was diagnosed with breast cancer in April 2023.

On Instagram, Olivia explained that she underwent genetic testing for breast cancer in February 2023, along with her sister Sara. The test checked for 90 different breast cancer genes. Olivia recalls that their results were good, writing, "I tested negative for all, including BRCA (the most well-known breast cancer gene.)" She also got clear results from her mammogram. But three months later, she was diagnosed with breast cancer.

“I was walking around thinking that I had no breast cancer,” she told People. “I did all the tests that I knew about.”

Olivia adds that she wouldn't have known she had cancer for another year—at her next scheduled mammogram—if her ob-gyn, Dr. Thais Aliabadi, hadn't decided to calculate her Breast Cancer Risk Assessment Score: "The fact that she did saved my life."

What is a Breast Cancer Risk Assessment Score?

Health professionals use the Breast Cancer Risk Assessment Tool (BCRAT), an interactive calculator, to estimate a woman's risk of developing breast cancer.

“Dr. Aliabadi looked at factors like my age, familial breast cancer history, and the fact that I had my first child after the age of 30. She discovered my lifetime risk was at 37%. "Dr. Aliabadi says that if the number is greater than 20%, you need annual mammograms and breast MRIs starting at age 30," she said on Instagram.

Because Olivia's lifetime risk was high, Dr. Aliabadi ordered an MRI, which revealed a tumor in her right breast that was "just a hairline away from my lymph nodes," the actress told People. An ultrasound then revealed two more tumors in her right breast, which biopsies revealed to be Stage 1 invasive cancer. Further review of the MRI confirmed cancer Olivia had cancer in her left breast, as well.

Olivia has encouraged her followers to have their doctor calculate their Breast Cancer Risk Assessment Score.

"I’m lucky. We caught it with enough time that I had options. I want the same for any woman who might have to face this one day," she wrote on IG.

The BCRAT is one of two models that can help estimate a patient's risk of getting breast cancer, Jason Aboudi Mouabbi, MD, a medical oncologist MD Anderson Cancer Center, Houston told Women's Health. The other one is the International Breast Cancer Intervention Study, or IBIS. While the BCRAT tends to underestimate risk, the IBIS tends to overestimate it, he says, so doctors use both to find a common range.

Should I get a Breast Cancer Risk Assessment Score?

Both the Breast Cancer Risk Assessment Tool and the International Breast Cancer Intervention Study tool are available online for free. Dr. Mouabbi encourages everyone to take them—no matter your age. But, he said it may be easier to do so alongside your primary care physician to understand any medical jargon.

If somebody is found to be high-risk for getting breast cancer in their lifetime (generally a score of over 20%), Dr. Mouabbi said there are a number of options. Those may include yearly MRIs (which most insurances will cover with a high BRCAT score), and the use of the estrogen receptor blocking medication Tamoxifen, which will decrease risk of breast cancer by 75%.

Overall, Dr. Mouabbi shared that keeping up with yearly mammograms is the most important step that patients can take to catch breast cancer early. He pointed out that 90% of Stage 1 breast cancers are curable.

What is Luminal B breast cancer?

Olivia's biopsy revealed that she had Luminal B breast cancer, one of four breast cancer subtypes (luminal A, luminal B, HER2-positive, and TNBC). Luminal A cancer cells are driven by hormones like estrogen and progesterone and tends to multiply more slowly, according to Dr. Mouabbi. Meanwhile, Luminal B can also be driven by a growth hormone, and is typically a more aggressive cancer. About 10 percent of breast cancer cases are Luminal B, according to the National Cancer Institute (NCI) Surveillance, Epidemiology, and End Results (SEER) database.

According to the Mayo Clinic, luminal B breast cancer "are likely to benefit from chemotherapy and may benefit from hormone therapy and treatment." Dr. Mouabbi confirmed that luminal B cancers require a "more urgent treatment approach."

Olivia said the experience made her realize what was truly important in life. "You realize cancer doesn’t care who you are. It doesn’t care if you have a baby or if you don’t have time," she told People. "It comes at you, and you have no choice but to face it head-on."

Olivia had four surgeries, including a double mastectomy.

Within 30 days of her breast cancer diagnosis, Olivia underwent three surgeries: A lymph node dissection, a nipple delay procedure, and a double mastectomy. A lymph node dissection removes an area of the lymph nodes that is cancerous or has a high likelihood of having cancer spread to it, according to the Canadian Cancer Society. Meanwhile, a nipple delay procedure creates new circulatory connections to the nipple, so it no longer depends on the breast tissue for its blood supply, per St. Vincent's Hospital. It is intended to spare the nipples ahead of a double mastectomy.

Olivia told People that she's "glad" she opted for the nipple delay surgery, although she didn't have to. "I want to give myself the best shot of keeping the parts of me that I can keep," she said.

The actress also underwent a double mastectomy in order to remove all of the known cancer and greatly reduce the risk of it returning. She had reconstructive surgery in the early fall.

"I know a lot of women want to go bigger, but [I said] go smaller," she told People. "It’s so important to say what you want out loud—and don’t stop. Even as the anesthesia was making its way into my body, the last thing I said was, 'Please go smaller.'"

Her breast cancer treatment put her in medically-induced menopause.

Olivia hasn't received radiation or chemotherapy so far, but she did begin hormone suppression therapy in November, after her double mastectomy. The experience put her body into a medically-induced menopause.

“I’m constantly thinking it’s hot, my hair is thinning, and I’m tired a lot,” she said, per People.

Medically-induced menopause is an anti-estrogen therapy that blocks the release of luteinizing hormone from the pituitary gland in the brain, Tracy O’Connor, M.D., previously told WH. “That stops the ovaries from making estrogen and helps to reduce the risk of cancer recurrence in premenopausal women with hormone-sensitive cancers,” she says.

Olivia says her son, Malcolm, 2, has remained her inspiration throughout it all.

"If my body changes, I’m still his mom. If I have hot flashes, I’m still his mom. If I lose my hair, I’m still his mom," she says. "That’s really what matters the most to me. I get to be here for him."

Her partner John Mulaney has been at her side.

Olivia specifically called out her partner, comedian John Mulaney, for supporting her throughout her journey.

"It would’ve felt like climbing an iceberg without him," Olivia says. "I don’t think he had a moment to himself, between being an incredibly hands-on father and going to and from the hospital—taking Malcolm to the park, putting him to nap, driving to Cedars-Sinai, hanging out with me, going home, putting Malcolm to bed, coming back to me. And he did it all happily."

In response to her announcement, John left the sweetest comment on her IG post. "Thank you for fighting so hard to be here for us. Malc and I adore you. ❤️."

Olivia's seen an outpouring of support from her friends.

Olivia's post is full of well wishes from her famous friends and followers.

Actress Jessica Chastain commented, "You are very generous to share your story. I believe in doing so, you’ve saved lives. So much love to you and your family 💕." Mindy Kaling also commented, "I love you. ❤", and Kaley Cuoco added, "Thank you for sharing this! Wow❤❤❤❤❤🙌🙌🙌🙌🙌." Gabrielle Union also commented, "❤️ Thank you for sharing mama. We gotchu ❤️"

Stylist Rachel Zoe wrote, "Wow Olivia you have already saved lives by sharing this. You are a brave warrior and I send you endless love healing and strength 🙏🏻❤️". And Olympic skier Lindsey Vonn added, "You are brave and strong and I’m thankful you are ok. Sending all the love ❤."

Rooting for you, Olivia!

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