Olivia Munn Shares Breast Cancer Diagnosis, Underwent Double Mastectomy

Olivia Munn is opening up about her battle with breast cancer. In a message shared to Instagram, the actress, 43, revealed that she had undergone a double mastectomy procedure—in addition to three other surgeries—following her diagnosis with Luminal B cancer, which she called “aggressive [and] fast moving.”

“I was diagnosed with breast cancer,” Munn captioned a post on Instagram, which featured photos and videos from her hospital stay as well as a lengthier message detailing her treatment. “I hope by sharing this it will help others find comfort, inspiration and support on their own journey.”

Munn learned of her cancer just a little over a year ago during a visit with her OBGYN, Dr. Thaïs Aliabadi. “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,” the actress wrote. “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 I was diagnosed with breast cancer.”

“Dr. Thaïs Aliabadi, decided to calculate my Breast Cancer Risk Assessment Score,” Munn added. “The fact that she did saved my life. 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%. Because of that score I was sent to get an MRI, which led to an ultrasound, which then led to a biopsy. The biopsy showed I had Luminal B cancer in both breasts. Luminal B is an aggressive, fast moving cancer.”

Munn said she “went from feeling completely fine one day, to waking up in a hospital bed after a 10-hour surgery the next.” The actress and mom of one explained that her health has improved significantly in the time since. “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.”

A-list stars flooded Munn’s post with messages of support. “You are very generous to share your story. I believe in doing so, you’ve saved lives” Jessica Chastain wrote. Gabrielle Union echoed that sentiment, saying “Thank you for sharing mama. We gotchu.” Munn’s husband of three years, John Mulaney, also showed his admiration, writing “Thank you for fighting so hard to be here for us. Malc and I adore you.”

Munn concluded her message by thanking Mulaney, saying “I’m so thankful to John [Mulaney] for the nights he spent researching what every operation and medication meant and what side effects and recovery I could expect. For being there before I went into each surgery and being there when I woke up.”