How does breast density affect screening sensitivity and cancer risk?

• A. Higher density reduces screening sensitivity and increases cancer risk.
• B. Higher density increases screening sensitivity and increases cancer risk.
• C. Density has no impact on sensitivity or risk.
• D. Higher density reduces screening sensitivity but lowers cancer risk.

Answer: (B)

Breast density affects two important things: how well a mammogram can detect cancers (screening sensitivity) and the actual risk of developing cancer. Dense tissue appears white on a mammogram, just like many cancers, which reduces contrast and makes small masses or calcifications harder to see. That masking effect lowers screening sensitivity in dense breasts. At the same time, higher density is an independent risk factor—more glandular and fibrous tissue is linked with a higher likelihood of developing cancer compared with fatty tissue. So, higher density both reduces the effectiveness of screening and increases cancer risk. The idea that density would increase screening sensitivity isn’t accurate; density makes detection harder and cancer risk higher, which is why supplemental imaging like ultrasound or MRI is often considered for dense breasts.