Research and progress in targeted cancer therapy today may someday lead to highly effective, customized treatment for cancer patients. Targeted cancer therapy—also called molecular targeted drugs or therapy—blocks the growth and spread of cancer by interfering with the tumor's growth.
Although environmental factors, age, and heredity all influence our risk of developing cancer, cancer ultimately arises from genetic mutations that convert normal cells into cancer cells. Our body is comprised of millions of cells that grow, divide, and die every day. This is a carefully regulated process in healthy individuals. When something damages or alters our cells, the abnormal cells divide without control, forming a tumor and invading other tissues.
Since scientists completed the human genome project in 2003, they have made remarkable progress identifying many cancer-specific mutations, which all provide targets for potential treatment or keys to prevention.
Physicians expect that targeted cancer therapy will be more effective than traditional treatments and cause significantly less harm to healthy cells. They can prescribe targeted therapy alone or in combination with other treatment. Currently, most targeted therapy is used with chemotherapy or other intervention to boost effectiveness.
Benefits of Targeted Cancer Therapy
Targeted cancer therapy can work in one of several ways. It can interfere with normal cell processes. Enzyme inhibitors, for example, block signals to and from cells that promote cancer cell growth. Some therapies modify the function of proteins that regulate activity in genes. Others cause tumor cells to die directly, sometimes by delivering toxic molecules to the cancer cells, or indirectly by helping the immune system destroy the tumor. Some types of targeted therapy work by cutting off the supply of oxygen and nutrients tumors need to grow.
By identifying specific targets present in tumors, physicians can tailor a patient's treatment based on his or her genetic profile. Targeted therapy may be more selective for cancer cells than normal cells, minimizing damage to the rest of the body.
Targeted cancer therapy is not a perfect solution. Some patients may develop resistance to the therapy so it's no longer effective. Targeted cancer therapy can also cause side effects and potentially serious reactions.
Currently, scientists have developed targeted therapies for a handful of cancers, including some types of leukemia, breast cancer, gastrointestinal cancer, advanced and metastasized non-small cell lung cancer, pancreatic cancer, gioblastoma (brain tumor), cancers of the head and neck, colorectal cancer, and advanced renal and kidney cancer.
Sources
National Cancer Institute. "Targeted Cancer Therapies." Web. 21 June 2010.
http://www.cancer.gov/cancertopics/factsheet/Therapy/targeted
National Cancer Institute. "Targeted Therapy." Web.
http://www.cancer.org/Treatment/TreatmentsandSideEffects/TreatmentTypes/targeted-therapy
Mahadevan, Daruka, MD, Ph.D. "Targeted Cancer Therapy." Medscape Medical News. Web. 3 January 2010. http://emedicine.medscape.com/article/1372666-overview
