What are the main chemotherapy drugs used for breast cancer?

The main chemotherapy drugs used for breast cancer are Adriamycin and Taxol or Taxotere. Those two compounds currently are the most important drugs and a close third is cyclophosphomide.

Are they effective?

They are effective. Chemotherapy for breast cancer works, and by that we mean it shrinks the cancer at least by 50 percent of its initial size. They work at least 70 to 80 percent of the time, meaning that if you have somebody who has either a large breast lump or has a growth somewhere else in their body, like the lungs or the bones or the liver, you give them these drugs and more than half of the time the cancer will shrink down by more than 50 percent.

It doesn't mean that the cancer is cured. In fact, I should say that if the cancer spreads outside the breast we do not currently have a cure for it. We can control it, often changing it into a more chronic pattern so that the person has a chronic illness like you have diabetes or hypertension or something like that, but you cannot really cure it and completely get rid of it.

How do chemotherapy drugs work?

Chemotherapy drugs work mostly by affecting the genetics of the cell. Cancer cells are immortal: they continue growing, they divide constantly as opposed to normal cells. Normal cells are born, they accomplish a function of some sort and then they die. The cancer cells are constantly dividing and that allows us to focus on them with these drugs. The drugs bind to the genetic material of the cell and when the cell tries to divide, instead of dividing it actually dies.