10/21/2025
Though breast cancer in the United States occurs primarily in middle-aged and older women, age is not the only risk factor for a breast cancer diagnosis. Many risk factors beyond age may contribute to a breast cancer diagnosis, and sometimes there are no discernable risk factors at all.
The average age of U.S. women diagnosed with breast cancer is 62 years old.
Half of U.S. women who develop breast cancer are 62 years of age or younger when they are diagnosed.
About 9% of all new breast cancer cases in the U.S. are diagnosed in women younger than 45 years old.
Younger people, particularly those under age 35 at the time of their original breast cancer diagnosis, face a higher risk of breast cancer recurrence.
