The five-minute quiz that helped catch Olivia Munn's cancer

Actor Olivia Munn recently shared in an Instagram post that a free risk-assessment tool her doctor used revealed that she had a higher chance of developing breast cancer. It led to testing and eventually treatment-that likely spared her from more serious outcomes.

- ALICE PARK

The Breast Cancer Risk Assessment Tool isn't new. It's been around since 1989 for women ages 35 to 74, and it doesn't even require a doctor. The online questionnaire, available through the National Cancer Institute (NCI), asks about a woman's age, her family history of breast cancer, when she began menstruating, how old she was when she had her first child (if applicable), and if she's had any breast biopsies. It then estimates her risk of getting breast cancer in five years and over the course of her life.

"This calculator is a great first step that women can do on their own and discuss the results with their primarycare doctor or gynecologist," says Dr. Jennifer Litton, professor of breast medical oncology at MD Anderson Cancer Center.