Olivia Munn says she had zero symptoms before she took a risk assessment test that helped detect her Stage 1 breast cancer, and she has since urged other women to take it.
The "Your Friends & Neighbors" star revealed she had been diagnosed with breast cancer in an Instagram post in March 2024. Munn learned she had Stage 1 breast cancer the year prior, in April 2023, after taking the lifetime risk assessment test, a questionnaire that estimates a person's lifetime risk of developing breast cancer, using personal information such as age, family history of breast cancer, date of first menstruation, and whether or not you've ever given birth, according to the National Institutes of Health.
Speaking with "Good Morning America" on Monday, Munn encouraged others to take the assessment themselves.
"The impetus for wanting to talk about it was that I had something that I knew would help women, something that was free -- the lifetime risk assessment test, it's a free online test -- and after a clear mammogram, clear ultrasound, it still detected my breast cancer," she said.
She added, "I'm doing great right now."
While the lifetime risk assessment test may help a doctor estimate one's breast cancer risk, it cannot determine whether or not they will get breast cancer.
This risk assessment is a widely available tool online, but doctors urge anyone who is worried about their breast cancer risk to talk to their health care provider, rather than try to evaluate it on their own, as there may be other things beyond the tool's input to consider.
A provider will also be able to discuss the results, potentially offer further diagnostic testing or screening, or may recommend other ways to better estimate cancer risk.
Munn previously revealed in an Instagram post that her risk assessment score was 37.3%, higher than the 20% high-risk threshold that typically prompts a recommendation for additional breast cancer screening or diagnostic tests.
After her diagnosis, Munn said she underwent a double mastectomy, an ovariectomy and a partial hysterectomy. She said her risk score is now zero.
She said she's now taking medications that come with "tough" side effects.
"And I say all that to kind of bond with anybody out there who's going through that or feeling comfort in their own journey," she said, "because it's not something that I've easily found. But I'm doing great."
Despite the struggles, Munn credits her family, including her husband, comedian John Mulaney, whom she married in 2024, for their steadfast support.
"I couldn't have gotten through this and climbed the mountain without him," Munn said of Mulaney.
She added, "He's been there through so many difficult parts of my life and made it, strangely to say, like, fun. Everything was just really -- [he's] just made everything light."
Munn and her husband share two children, Malcolm, 4, and Mei Mei, who will turn 2 this fall.
