Chemotherapy drugs are used to halt the division and reproduction of cancer cells, but can also damage some of the more sensitive normal cells, such as bone marrow, linings in the mouth and digestive system, and hair follicles (which accounts for the classic hair loss). The cancer cells cannot survive after attack by chemotherapy drugs, but the affected healthy cells can. Most of the cellular damage recovers once the chemotherapy regimen is complete.
Each chemotherapy drugs has a unique mode of halting and killing the cancer cells. Many times various drugs are used in combination to attack the cancer cells from more than one way. There are over 200 chemotherapy drugs used in as many as 50 combinations. Certain cancers, prostate cancer, for instance, develop resistance to a single chemotherapy agent and so, for that situation, a combination treatment may be more successful.
Typically, chemotherapy is administered intravenously or through a port. The actual time at the hospital or clinic is around 2 hours for administration. Some newer drugs actually come in pill form. Treatments are given in a series, usually once every two or three weeks. This allows a ‘rest period’ for the patient, recovering from side effects. Directly after chemotherapy, an anti-sickness medication is given to lessen the unpleasant side effects. The rest period also gives the sensitive healthy cells a chance to recover, as more and more cancer cells are destroyed.
Chemotherapy has the potential to completely cure the disease by destroying all of the cancer cells. Sometimes a course of treatment is extended, even when there is no more evidence of cancer. This is to eliminate possible cancer cells that are too small for detection. In advanced stages of cancer, chemotherapy may be administered more for quality of life - to reduce the tumor, which would ease pain and prolong life.
Strategies for Chemotherapy use
Chemotherapy is used pre-operatively to shrink the tumor, making it easier to remove and surgery less invasive. In a post-operative treatment plan, chemotherapy is almost used as a preventive, to kill any cells which are too small for detection and removal during surgery. Some cancers may not be able to be completely removed during surgery, because of the risk to the patient. In this case, chemotherapy is used, not as a cure, but to reduce the tumor, and thus, the symptoms.
In cooperation with radiation, chemotherapy works together to more quickly eradicate cancer cells.
Bone marrow transplants are indicated when using high-dose chemotherapy. This is for certain cancers that may be very aggressive in growth and spread. A major side effect of the high-dose therapy is the destruction of bone marrow. Stem cells are used to replace the bone marrow. These cells may originate from the patient or a matching donor. Again, this is a specific treatment for only a very few types of cancer.
Mechanisms of Cancer Cell Destruction
As stated earlier, chemotherapy drugs were on unique areas of the cancer cell. Some of the older drugs are not as specific and cause more of the unpleasant side effects. New drugs have been developed which may target the outer cell wall of the cancer cell, the reproductive mechanism on the inside of the cell, and a ‘death receptor’ on the cancer cell, which can cause cell death.
Most often, chemotherapy drugs are used in combination with each other, surgery, radiation, hormone replacement therapy, and biological therapy. Since each person and cancer is unique, the treatment must be, as well.
To learn more about chemotherapy the symptoms, treamtent cycles and alternative therapies, visit the Cancer Breakthroughs website.