Molecular targeted therapy is a type of cancer treatment which attempts to interfere with specific molecules involved in the growth of cancer. These therapies are sometimes termed "smart" medicines because they have the ability to attack tumor cells while sparing healthy cells (1).
Certain abnormal parts of cells are responsible for controlling how cancer cells abnormally grow, divide, spread, and survive much longer than normal cells. These parts of cancer cells are called molecular abnormalities, and blocking these abnormal molecules can lead to the death of cancer cells (1). The molecular targeted therapy drugs target the processes, pathways, and unique physiology which are particular to cancer cells, and thus they have the ability to reduce the cancer's destructive behavior (2).
Most molecular targeted therapies are still in the experimental stages, though the FDA has approved several drugs for certain types of cancer, including treatments for breast cancer, colon cancer, and lung cancer. Because these medications are specific to cancer cells, they have fewer side effects than traditional chemotherapy drugs. A challenge to those developing such therapies is that often the growth and spread of cancer cells is not due to a single defect in the molecular structure of the cells, but to many defects. It is expected that as doctors and researchers continue to learn more abut how cancer develops, more and better molecular targeted drugs will become available (3, 4).