Dense breasts can make it harder to spot cancer on a mammogram

(Carla K. Johnson/ the Hamilton Spectator) — When a woman has a mammogram, the most important finding is whether there’s any sign of breast cancer.

The second most important finding is whether her breasts are dense.

Since early September, a new U.S. rule requires mammography centers to inform women about their breast density — information that isn’t entirely new for some women because many states already had similar requirements.

Here’s what to know about why breast density is important.

Are dense breasts bad?

No, dense breasts are not bad. In fact, they’re quite normal. About 40% of women ages 40 and older have dense breasts.

Women of all shapes and sizes can have dense breasts. It has nothing to do with breast firmness. And it only matters in the world of breast cancer screening, said Dr. Ethan Cohen of MD Anderson Cancer Center in Houston. (…)