Olivia Munn's "no symptoms" cancer diagnosis fueled lifesaving mission

Olivia Munn is known for commanding the screen, but in recent years, she's taken on a more personal role: cancer survivor, advocate, and mother.

In April 2023, Olivia Munn discovered she had Stage 1 breast cancer after taking the Lifetime Risk Assessment test, a free online Q&A that takes minutes to provide a score estimating your risk of developing breast cancer in your lifetime.

Anything above 20% is considered high risk. Munn's risk score was x37.3%.

"No symptoms. And I had a clear mammogram and a clear ultrasound," Munn told "CBS Sunday Morning."

Once she learned the diagnosis, she fought back with everything she had. She got a double mastectomy, an ovariectomy and a partial hysterectomy. Now her score is zero.

Instead of recovering quietly, she sounded the alarm, posting online about her cancer and telling everyone who'd listen about the risk assessment test. In the years since Munn started sharing her story, the number of women taking the test has increased by 4,000 percent.

"Knowing that it's really changed so many people's lives. It's been the most amazing thing. There's no way I could have ever predicted it," she said. 

In 2021, she started dating comedian John Mulaney. The two were married in 2024, and he has been by her side every step of the way during her breast cancer fight.

"There's no better person in the world to me than my husband. He is-- I mean, you've met him. He wanted to come to every single doctor's appointment. He had his little notebook. You know? And he's got his notebook that he writes all of his ideas for jokes and anything that comes to him through the day," Munn said. 

Munn said Mulaney jotted down notes about cancer and hormone therapy and helped lighten the mood.

"You know, having the humor to go through it and having someone who's so funny, it really– it just lightens everything," she said.

Their son Malcolm is 4 and daughter Mei Mei will be 2 in the fall. Being a parent reminds her how fast life can change.

"I say it's not the Christmases and the birthdays and the New Year's that we remember. Like, life happens on a Tuesday. Like, it just happens. And you cannot expect it. And so every day, you should just be so present and grateful," Munn said, reminding parents to enjoy all the "tiny, little moments" with their children.

She continued, "And once you are faced with the possibility of death and not being here, it's-- for me, all I wanted were the little moments."

Thanks to Munn and her determination to share her story, countless other women can have a few more little moments, too.

Despite the challenges, Munn said she feels incredibly lucky. She doesn't view her experience as something cancer has taken from her, but rather as a reminder of how fortunate she is to still be here.

"I'm so lucky that I'm in this chaos, and that I haven't slept in a few days, and that I'm exhausted. It's a true privilege to just be alive in the world," Munn said.

These days, Munn is keeping busy on set, filming her role as a devious divorcee in the Apple TV+ series "Your Friends and Neighbors," which returns for its second season on Friday, April 3, 2026.