LOS ANGELES — Actress Olivia Munn announced Wednesday that her mother has been diagnosed with breast cancer, crediting the same risk assessment test that led to her own cancer diagnosis in 2023 with potentially saving her mother's life.
Munn, 44, shared the news in an Instagram post, revealing that her mother, Kim Munn, was diagnosed with Stage 1 HER2 breast cancer after scoring 26.2% on a Breast Cancer Lifetime Risk Assessment test. HER2-positive breast cancer is a fast-growing form of invasive breast cancer, according to the Cleveland Clinic, which accounts for about 15-20% of invasive breast cancer cases.
"After my own breast cancer diagnosis in 2023, I urged my mother and sister to take the Breast Cancer Lifetime Risk Assessment test," Munn wrote. "My mother scored 26.2%. Her yearly mammogram had just come out clear but because of that high score I insisted she get an MRI."
The MRI revealed the cancer, despite a clear mammogram result. Munn's mother has since completed 12 rounds of chemotherapy and will continue monthly Herceptin transfusions until fall. She also underwent a double mastectomy.
Munn described caring for her mother during treatment as "heartbreaking," writing that she "spent many nights taking care of my mom when the chemo became too much, wishing I could fight the fight for her."
The actress, known for her roles in "The Newsroom," "Magic Mike" and "X-Men: Apocalypse," was diagnosed with Luminal B breast cancer in both breasts in 2023. She underwent a double mastectomy and four surgeries over 10 months before publicly sharing her diagnosis in March 2024.
Munn said her doctor saved her life by calculating her Breast Cancer Risk Assessment Score, which led to an MRI and biopsy that revealed the aggressive, fast-moving cancer. She had tested negative for 90 different cancer genes, including BRCA, just months before her diagnosis.
The actress has been in a relationship with comedian John Mulaney since 2021 and they got married in 2024. The couple has two children: son Malcolm, born in November 2021, and daughter Méi, born via surrogate in September 2024.
Munn's Instagram post included photos from her mother's treatment journey, including images from her first day of chemotherapy and the moment she rang the bell signifying the end of treatment.
"Going through cancer is really hard," Munn wrote. "But there's something about watching a loved one go through it that is even more heartbreaking."
"To anyone out there who is taking care of someone or has made it their profession to do so, thank you," she added. "These fights can fear near impossible without you."
