Medically reviewed by Sonya Bhole, MDTriple-negative breast cancer more commonly affects people under 40, earlier than routine screenings start.Credit: Olga Pankova / Getty ImagesGuidelines recommend standard screening using mammograms for breast cancer, including triple-negative breast cancer (TNBC), from age 40. However, TNBC more commonly affects those under 40.This can mean that many people, especially Black people who are disproportionately…