How fast does invasive breast cancer grow?

Answer 1

Most women are shocked to find out that they have had their Breast cancer for years before it was discovered. Cancer growth is measured in doubling times. One doubling time is the amount of time that it takes for the mass of cancer cells to double in size. It takes about 23 doubling times to go from one cancer cell to become a large enough mass to be seen on a mammogram, and about 30 doubling times to become large enough to be felt as a lump, about one billion cells. Doubling times may be as short as 10 days or as long as several years. Four months is an average doubling time. A cancer's doubling time is an indication of how fast it grows. The doubling time is very important in determining the time course of the cancer. For example, a cancer first starts when a woman is 40. It is a fast growing cancer with a doubling time of 2 months. It takes 46 months (2x23), or almost four years, before it is large enough to be detected by a mammogram and 60 months, or five years, before she feels it. She is diagnosed with cancer at age 44 or 45. If, on the other hand, she has a slow growing cancer with a doubling time of two years, she would be 86 before it could be found on a mammogram and 100 before she could feel it. She probably would die of other causes before she ever knew she had cancer. Carefully performed autopsy studies show undetected invasive Breast cancer in over 3% of women age 40 and older. Since most breast cancers grow at an intermediate pace, usually the cancer has been present for 8-10 years before being discovered. Metastatic cancer, like the original cancer in the breast, must double in size at least 23 times before it can be found.