Targeted therapies are systemic biologic drugs that have a specific molecular target in cancer cells. They act mainly on those targets with the goal of leaving the healthy cells unharmed. Some may prevent the growth of new blood vessels that supply tumor cells with blood, oxygen and other nutrients. Others bind to special sites on the cell surface to stop the cell's growth and promote cell death.
Since chemotherapy's side effects are often the result of harming the healthy cells along with the cancer cells, the targeted therapies offer new possibilities.
Though not for every type of cancer, targeted therapies are one more important tool available for treatment of cancer.