How quickly does breast cancer grow?

Variable: It is estimated that by the time a cancer is detected on a mammogram, it has probably been present for 2 years and that it takes an average of 5 years to become palpable. However, the growth rates of different breast cancers can vary substantially.

Varies: Each cancer is unique. Some cancer cells grow very rapidly have the ability to metastasize very early in their development while others grow much slower and are late to metastasize. This is very difficult to predict.