Actress Olivia Munn has revealed that her mother, Kim Munn, was recently diagnosed with breast cancer — just two years after Olivia herself began her own fight against the disease.
In a heartfelt Instagram post shared on Wednesday, the Newsroom star, 45, opened up about her mother’s diagnosis and treatment journey, describing it as “even more heartbreaking” than facing the illness herself. Olivia, who was diagnosed with Luminal B breast cancer in 2023, urged her mother to take the same Tyrer-Cuzick risk assessment test that had played a crucial role in her own diagnosis.
“I never would’ve predicted it would save my mom’s life as well,” Munn wrote, explaining that despite a clear mammogram, her mom’s high risk score prompted her to push for further testing. That led to a stage 1 HER2-positive breast cancer diagnosis.
Kim has since completed 12 rounds of chemotherapy and continues to receive monthly Herceptin treatments, Olivia said. “From my mom being there for me after my double mastectomy, to me doing the same after hers — I can tell you this: going through cancer is incredibly hard. But watching a loved one go through it… that’s even harder.”
Munn included intimate photos and videos of her mother’s treatment, including the emotional moment she rang the bell to mark the end of chemo. She also thanked her mother’s husband, Sam, for joining her in researching every treatment option — from chemotherapy and immunotherapy to the use of cold caps.
“I spent so many nights caring for my mom when the chemo got too rough, wishing I could fight it for her — even for just one day,” Munn wrote. “Realizing you can’t take their place is one of the hardest parts.”
Munn, who shares two children — Malcolm Hiệp and Méi June — with husband John Mulaney, has been open about her own breast cancer battle. Since her diagnosis, she’s undergone multiple surgeries including a double mastectomy, hysterectomy, and oophorectomy.
She credited the breast cancer risk assessment test with saving both her life and her mother’s. “We’re taught about Pap smears and mammograms at 40, but every gynecologist needs to incorporate lifetime risk assessments into regular care,” she urged. “These tests matter. My mom wanted me to share her story in hopes it might help save someone else’s life.”
In her signature blend of humor and warmth, Munn added: “She’s handled everything with so much courage and still drives us nuts — like trying to do laundry and make dinner after her mastectomy. She’s insane, in the best way.”
Munn first disclosed her diagnosis publicly in March 2024, revealing that although she had tested negative for 90 known cancer genes (including BRCA), her OBGYN went the extra step and calculated her risk score — which ultimately led to early detection. “I went from feeling completely fine one day to waking up in a hospital bed after a 10-hour surgery the next. I’m lucky we caught it in time.”
She later told Vogue that she opted for a full hysterectomy after suffering difficult side effects from estrogen-blocking medication. Before the procedure, she froze her eggs for a third time. She and Mulaney welcomed their daughter via gestational surrogate in September 2024.
“I had so many emotions about not being able to carry her,” Munn wrote at the time. “But when I met our surrogate, we connected instantly. She was a real-life angel who carried our daughter safely and helped make our dream come true.”
Munn ended her latest post by thanking the doctors, nurses, and care team who helped guide both her and her mother through their cancer journeys: “To everyone who gives care — professionally or personally — thank you. These gifts would be impossible without you.”
