Dense breast tissue: What it means to have dense breasts Dense breast tissue: What it means to have dense breasts Dense breast tissue is detected on a mammogram. Additional imaging tests are sometimes recommended for women with dense breasts.By Mayo Clinic Staff If a recent mammogram showed you have dense breast tissue, you may wonder what this means for your breast cancer risk. Doctors know dense breast tissue makes breast cancer screening more difficult and it increases the risk of breast cancer. Review your breast cancer risk factors with your doctor and consider your options for additional breast cancer screening tests. Together you can decide whether additional screening tests are right for you.