How does targeted cancer therapy work?
Most standard chemotherapy (chemo) drugs work by killing cells in the body that grow and divide quickly. Cancer cells divide quickly, which is why these drugs often work against them. But chemo drugs can also affect other cells in the body that divide quickly, which can sometimes lead to serious side effects. On top of this, chemo drugs don’t always work against cancer, or sometimes they stop working after a while.
Targeted therapy drugs work differently. These drugs target certain parts of cancer cells that make them different from other cells. (Or they target other cells that help cancer cells grow.)
Cancer cells typically have many changes in their genes (DNA) that make them different from normal cells. These gene changes might cause the cell to make too much of a certain protein, which in turn might make the cell grow and divide too quickly. These types of changes are what make it a cancer cell.
But there are many different types of cancer, and not all cancer cells are the same. For example, colon cancer and breast cancer cells often have different gene changes that help them grow or spread. Even among different people with colon cancer, the cancer cells can have different gene changes.
Targeted drugs zero in on some of the changes that make cancer cells different. But just as cancer cells can have many different gene changes, these drugs can attack many different targets. This affects which cancers they might be helpful against, as well as which side effects each drug can cause.
Some targeted drugs are more “targeted” than others. Some might target only a single abnormal protein in cancer cells, while others can affect several different proteins in cancer cells. Others just boost the way the body fights the cancer cells. Again, this can affect where these drugs work and what side effects they cause.
Targeted drugs are often grouped by how they work or what part of the cell they attack. The ways in which some different types of targeted drugs work are described in more detail in the next section.
Last Medical Review: 12/08/2014
Last Revised: 12/11/2014