Inside Olivia Munn's Inspiring Breast Cancer Journey After Her Diagnosis at 43
"I had no idea how healing it would be to come out with my story," the TODAY with Jenna & Friends guest co-host said.
Olivia Munn has been using her platform and her own personal journey to help raise invaluable awareness about breast cancer.
Despite initial tests saying she was in the clear, Munn was ultimately diagnosed with an aggressive form of breast cancer at 43 years old. Since then, Munn has undergone several surgeries, including a double mastectomy and hysterectomy. She also went through hormone suppression therapy and froze her eggs.
Throughout this life-changing journey, Munn has also been raising her two children with husband John Mulaney. Munn gave birth to their son, Malcolm Hiệp Mulaney, in November 2021, before she was diagnosed with breast cancer. The couple then welcomed their second child, daughter Méi June Mulaney, in September 2024 via surrogate.
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Munn has shared that motherhood is what influenced her approach to her treatment. “You start thinking about your mortality differently once you have a baby,” Munn told Vogue in May 2024. “It was a big decision to make, but it was the best decision for me because I needed to be present for my family … It’s my motherhood, and I don’t want to miss any of these parts if I don’t have to.”
Today, Munn has said she's “grateful” she feels healthy, appearing as a guest co-host on TODAY with Jenna & Friends and walking red carpets with Mulaney, including at the SNL 50: The Anniversary Special. Read on to look back at what Munn has shared about her breast cancer journey and the risk assessment score she’s credited with saving her life.
Olivia Munn was diagnosed with breast cancer in April 2023 and had a double mastectomy 30 days later
Munn revealed in an Instagram post that she’d been diagnosed with breast cancer in April 2023 after her OB/GYN advised her to calculate her Breast Cancer Risk Assessment Score.
“In February of 2023, in an effort to be proactive about my health, I took a genetic test that checks you for 90 different cancer genes,” she wrote in March 2024. “I tested negative for all, including BRCA (the most well-known breast cancer gene). My sister Sara had just tested negative as well. We called each other and high-fived over the phone. That same winter I also had a normal mammogram.”
Two months later, however, Munn received a breast cancer diagnosis. “In the past 10 months I have had four surgeries, so many days spent in bed I can't even count and have learned more about cancer, cancer treatment and hormones than I ever could have imagined," she continued, adding that she kept her diagnosis and treatment private at the time because she “needed to catch my breath and get through some of the hardest parts before sharing.”
Munn said her cancer would have gone undetected for another year when her next mammogram was scheduled, but her OB/GYN, Dr. Thais Aliabadi, decided to calculate her Breast Cancer Risk Assessment Score. “The fact that she did saved my life,” Munn wrote, calling her doctor her “guardian angel.”
Munn’s score — a lifetime risk of 37% — then led to an MRI, an ultrasound, and then a biopsy, which found Luminal B cancer in both breasts. “Luminal B is an aggressive, fast moving cancer,” Munn wrote, adding that she underwent a double mastectomy 30 days later.
“I’m lucky. We caught it with enough time that I had options,” she continued. “I want the same for any woman who might have to face this one day. Ask your doctor to calculate your Breast Cancer Risk Assessment Score.”
What is a Breast Cancer Risk Assessment Score?
Also known as the Tyrer-Cuzick Risk Assessment Calculator, the breast cancer risk questionnaire Munn referred to evaluates several factors including your age, reproductive history, as well as personal and family medical history. The Gail Model is another tool to estimate a woman's risk of breast cancer, and both tests are free and available online.
If a score is 20% or greater, as was the case for Munn, a patient would be considered “high risk” for developing breast cancer and a medical professional may advise further tests such as annual mammograms, an MRI, or ultrasound.
“I had no idea how healing it would be to come out with my story and to see how many women have gotten this test and how many women’s lives this could save,” Munn shared on The Kelly Clarkson Show in May 2024.
Mulaney also shared during an interview with CBS Sunday Morning in March 2025 that it’s been “astonishing” to see how much this test has helped other women. “[The risk calculator] is really the only reason her cancer was discovered,” Mulaney said. “Seeing so many women, publicly and privately, come to her that they discovered how high their risk was because of that. It’s astonishing.”
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Olivia Munn has urged women to advocate for themselves after her breast cancer diagnosis
During an October 2024 appearance on TODAY, Munn shared with Savannah Guthrie that in addition to calculating your breast cancer risk score, she’s also learned how important it is to advocate for yourself during her breast cancer journey.
“They say advocate for yourself … but what does that really mean?" she said. "What I’ve learned is that means you gotta go to your doctor and you inundate them with information and you don’t stop until they give you the tests that you need. Don’t let them send you off, don’t let them tell you that it’s nothing to worry about. You have to keep fighting for yourself.”
Olivia Munn says she has “years to go” in her breast cancer treatment
Roughly two years after she was first diagnosed, Munn shared in February 2025 that while she still has “years to go” in her breast cancer treatment, she’s feeling healthy.
“I’d like to propose a toast to good health. A toast to healthy days,” Munn said at TIME’s Women of the Year gala, going on to share a story about her daughter Méi suffering through “a lot of discomfort” and stomach pains. Crediting her “mother’s intuition,” Munn decided to switch her formula and shared that within hours Méi was feeling better.
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“It’s one of my most proud moments as a mother ever … she was smiling and she was healthy, and then I realized that I’d felt pretty good all day too,” she said. “I have years to go in my cancer treatment, but on that Friday my joints didn’t ache, and I wasn’t too hot or too cold from going into a surgical menopause, and my brain fog had cleared, at least for that day anyway … As I held my daughter, I was so grateful that I was healthy enough to see every minute of it all.”
