Targeted cancer treatments use drugs that obstruct the development and spread of cancer by disrupting particular molecules involved in carcinogenesis (the procedure by which regular cells end up being cancer cells) and tumor development (see Questions 1, 2, and 3).
Because scientists call these molecules “molecular targets,” therapies that disrupt them are sometimes called “molecular-targeted drugs,” “molecularly targeted therapies,” or other comparable names (see Concern 1).
The National Cancer Institute’s Molecular Targets Development Program is working to identify and evaluate molecular targets (see Question 6).
1. What are targeted cancer therapies?
They interfere with specific molecules involved in carcinogenesis (the procedure by which regular cells become cancer cells) and tumor development. By concentrating on molecular and cellular modifications that are specific to cancer, targeted cancer therapies might be more effective than present treatments and less dangerous to regular cells.
Most targeted cancer treatments are in preclinical screening (research study with animals), however some are in professional trials (research studies) or have actually been authorized by the U.S. Fda (FDA). Targeted cancer therapies are being studied for use alone, in mix with each other, and in mix with other cancer treatments, such as chemotherapy.
2. What are some of the cellular changes that lead to cancer?
Typically, cells divide and grow to form brand-new cells as the body requires them. When cells grow old, they die, and new cells take their place. In some cases this orderly process fails. Brand-new cells form when the body does not need them, and old cells do not pass away when they should. These extra cells can form a mass of tissue called a development or tumor. The cells in deadly (malignant) tumors are abnormal and divide without control or order. They can invade and harm neighboring tissues and organs. Cancer cells can break away from a deadly tumor and spread to other parts of the body.
Regular cell growth and department are mostly under the control of a network of chemical and molecular signals that provide guidelines to cells. Tumor suppressor genes are regular genes that slow down cell development and department. When a growth suppressor gene does not work effectively, cells might be unable to stop dividing and growing, which leads to tumor growth.
To use the metaphor of a vehicle, the existence of an oncogene is like having a gas pedal that is adhered to the floorboard, triggering cells to continually divide and grow. Tumor suppressor genes act like a brake pedal. The loss of a functioning growth suppressor gene resembles having a brake pedal that does not work appropriately, enabling cells to continually divide and grow.
When molecules called growth aspects (GFs) connect to their corresponding growth aspect receptors (GFRs) on the surface of the cell, a procedure brought out by proteins indicates the cell to divide. Cancer establishes when abnormal proteins inside a cell cause it to recreate excessively and permit that cell to live longer than typical cells.
3. How do targeted cancer therapies work?
Targeted cancer therapies interfere with cancer cell growth and division in various methods and at various points during the development, development, and spread of cancer. Many of these treatments focus on proteins that are associated with the signaling procedure. By blocking the signals that inform cancer cells to grow and divide frantically, targeted cancer treatments can help to stop the growth and division of cancer cells.
4. Exactly what are some kinds of targeted cancer therapies?
Targeted cancer therapies include several kinds of drugs. Some examples are listed below:
“Small-molecule” drugs obstruct particular enzymes and GFRs included in cancer cell development. Gleevec targets unusual proteins, or enzymes, that form inside cancer cells and promote unrestrained development. Iressa Â® (ZD1839 or gefitinib) is approved by the FDA to deal with innovative non-small cell lung cancer.
“Apoptosis-inducing” drugs cause cancer cells to go through apoptosis (cell death) by interfering with proteins involved in the process. Velcade Â® (bortezomib) is accepted by the FDA to deal with several myeloma that has actually not responded to other treatments (3). Velcade causes cancer cells to pass away by blocking enzymes called proteasomes, which help to manage cell function and development. Another apoptosis-inducing drug called Genasense â�¢ (oblimersen), which is only readily available in scientific trials, is being studied to deal with leukemia, non-Hodgkin lymphoma, and strong tumors. Genasense blocks the production of a protein known as BCL– 2, which promotes the survival of tumor cells. By blocking BCL– 2, Genasense leaves the cancer cells more susceptible to anticancer drugs.
Monoclonal antibodies, cancer vaccines, angiogenesis inhibitors, and gene therapy are considered by some to be targeted therapies since they interfere with the development of cancer cells.
5. What impact will targeted therapies have on cancer treatment?
Targeted cancer therapies will give doctors a better way to tailor cancer treatment. Eventually, treatments may be individualized based on the unique set of molecular targets produced by the patient’s tumor. Targeted cancer therapies also hold the promise of being more selective, thus harming fewer normal cells, reducing side effects, and improving the quality of life.
6. What are some resources for more information?
The NCI’s Molecular Targets Development Program (MTDP) is working to identify and evaluate molecular targets that may be candidates for drug development. As part of the NCI’s Center for Cancer Research, the MTDP provides research support for NCI-designated, high-priority drug discovery, development, and research focused on specific molecular targets, pathways, or processes. The MTDP’s Web site is http://home.ncifcrf.gov/mtdp/ on the Internet.
People also have the option of searching for clinical trials on their own. The clinical trials page of the NCI’s Web site, located at http://www.cancer.gov/clinicaltrials/ on the Internet, provides information about clinical trials and links to PDQ.