‘My cancer was not in those pictures’: how breast density affects mammograms

‘There’s a lot that’s not understood about breast density and why some [people] have more dense breasts than others,’ says Dr Angela DeMichele, professor of medicine at University of Pennsylvania. Photograph: Nakamura Tsune/Artvee

In 2017, 55-year-old Leslie Ferris Yerger underwent a routine mammogram and breast ultrasound. Both came back clear. Two months later, she had an unrelated Dexa scan to measure her bone density. The technician noticed an abnormality in her hip. After additional testing, Yerger was diagnosed with stage four breast cancer – an advanced stage of the disease in which the cancer has spread beyond the breasts.

The mammogram and ultrasound had not picked up the cancer because, Yerger would learn, of her dense breast tissue.