"Dirty" cancer fighter: Medicine's next big thing?



BACKGROUND:  More than one million people in the United States get cancer each year.  Cancer is a general name for a group of more than 100 diseases.  There are many kinds, but all cancers start because abnormal cells grow out of control.  Normal body cells will grow, divide, and then die.  Cancer cells will continue to grow and form more abnormal cells, instead of dying.  The cancer cells can also invade other tissues.  When the DNA of a cell is damaged, it will become a cancer cell.  When the DNA gets damaged in a normal cell, the cell will either die or repair the damage.  Some people inherit abnormal DNA, but most DNA damage is caused by mistakes that happen while the normal cell is reproducing or by something in the environment.   In most cases, cancer will form a tumor.  Cancer is named for the place where it started.  For example, breast cancer that has spread to the liver is called metastatic breast cancer, not liver cancer.  (Source: www.cancer.org)

 TREATMENT:  The most common types of cancer treatment are surgery, chemotherapy, radiation therapy, and many others.  Most people with cancer will have some type of surgery.  It can be used to diagnose, treat, or even help prevent cancer in some cases.  If the cancer has not spread to other areas of the body, then it can offer the greatest chance for cure.  Chemotherapy is the use of drugs and medicines to treat cancer.  It kills any cell that is growing fast, even if it is a noncancerous cell.  Radiation Therapy uses high-energy waves or particles to destroy or damage cancer cells.  Special equipment sends high doses of radiation to the cancer cells or tumors.  It can also affect normal cells that are near the tumor, but they can repair themselves.  There is also targeted therapy.  It is a newer cancer treatment that uses drugs or other substances to attack cancer cells.  Immunotherapy is another type of treatment; it uses your body’s own immune system to help fight cancer.  Stem cell transplants can be used also.  Photodynamic therapy (PDT) is a treatment that uses drugs, called photosensitizing agents coupled with light to kill cancer cells.  The drugs work when they have been activated by certain kinds of light.  (Source: www.cancer.org)

 NEW TECHNOLOGY:  There are many available treatments for cancer, but now rapamycin (also called sirolimus) is being tested in cancer patients for its antitumor activity.  Currently rapamycin is FDA approved as an antibiotic and immunosuppressant.  It is also being used in organ transplant patients and is in phase II and III clinical trials.  (Source: www.standford.edu)  Rapamycin blocks certain white blood cells that can reject foreign tissues and organs.   Rapamycin has promising therapeutic agents, including anti-tumor properties.  These actions are mediated through the inhibition of the mTOR protein kinase; mTOR is part of a conserved signaling pathway that controls the cell cycle in response to changing nutrient levels.  The mTOR signaling network contains a large number of tumor suppressor genes and also a number of proto-oncogenes, and mTOr signaling is activated in many types of tumors.  The observations about mTOR make it an ideal target for anti-cancer agents and rapamycin is such an agent.  Clinical studies have shown that rapamycin has efficacy as anti-tumor agents alone and when combined with other therapies.  Rapamycin inhibits tumor growth by halting tumor cell proliferation, inducing tumor cell apoptosis, and suppressing tumor angiogenesis.  (Source: www.ncbi.nlm.nih.gov)