CHICAGO — A new study shows 25% of breast cancer cases happen before the age of 50.

Researchers at the Radiological Society of North America’s annual meeting in Chicago also reported that more than 20% of breast cancers were found in women ages 18 to 49.

Researchers highlight that there’s a high number of cases in women under 40, a group at this time that does not have any screening guidelines.

The team looked at around 1,800 breast cancers in women under 50 over an 11-year period as part of the study.