A cancer growth inhibitor blocks the growth factors that make cancer cells grow. Growth factors are substances that control cell growth. Growth factors attach to receptors on a cancer cell. The receptors then send a signal to the inside of the cell, which triggers reactions that make the cell grow. Each growth factor has a matching receptor on a cancer cell.
Different growth factors do different things. Some make cells grow and divide into new cells. Other growth factors tell cells to stop growing or to die. Examples of growth factors include those that control:
Some cancer growth inhibitors are anti-angiogenesis drugs (they stop blood vessel development) and others are monoclonal antibodies. Cancer growth inhibitors are named after the growth factor that they block. There are 3 main types of cancer growth blockers.
Tyrosine kinase inhibitors (TKIs) block chemicals called tyrosine kinases. These chemicals are part of the signalling process within cells. When this process is blocked, the cell stops growing and dividing.
Examples of tyrosine kinase inhibitors include:
These tyrosine kinase inhibitors are taken by mouth.
Proteasomes are growth factors found in all cells. They help break down proteins that the cell doesn’t need. Once the proteins are broken down, the cell can reuse them to make new proteins that it does need. When proteasomes are blocked, proteins build up and the cancer cell dies.
Bortezomib (Velcade) is an example of a proteasome inhibitor. Bortezomib is given directly into a vein (intravenously, or IV injection).
Growth factor receptor inhibitors attach to the receptors on a cell and block growth factors in the blood from getting to the cell. This stops the cell from growing and dividing.
Examples of growth factors receptor inhibitors include:
For more detailed information on specific drugs, go to sources of drug information.