The term chemotherapy can refer to any medicinal therapy, but the common usage and association for the term specifically relates to the drugs used in cancer treatment. There are over 100 different chemotherapy medications, most of which are administered systemically. This means they are delivered intravenously---through the use of a vein---and travel through the blood stream. Some chemotherapy is also locally administered, or injected right into the site of the tumor. Still other chemotherapies are given orally, in pill form. Chemotherapies may be given in conjunction with biotherapies, which involve the use of living organisms to help treat cancer.
How It Works Works
Cells within the body are made up of living tissue that goes through five stages of development. When a cell reproduces, it passes through each of these five stages of development. When it is finished, the two cells (the original cell and its reproduction) are exactly the same. Chemotherapy drugs stop cells from reproducing by interrupting one of the five stages of development. Unfortunately, chemotherapy drugs usually can't tell the difference between cancer cells and healthy cells, which is why other cells that reproduce frequently (such as hair follicle cells and the cells in the digestive track) are adversely affected by chemotherapy. The reproduction cycle is interrupted, causing the nausea, vomiting, hair loss and other side effects associated with chemotherapy.
Biotherapy may be administered simultaneously with chemotherapy or before or after chemotherapy. Biotherapy (called HGF or hematopoietic growth factors) may be given during chemotherapy to help stimulate the growth of bone marrow stem cells, which may be impacted by chemotherapy. Interlukin biotherapy may be administered to help boost the growth of immune cells destroyed by chemotherapy, while interferon biotherapy may be administered to also aid in boosting immune response.
Guidelines for Choosing a Chemotherapy/Biotherapy Agent
A number of different factors go into choosing which chemotherapy treatment to use on a patient. The essential factors vary by patient and include the origin of the cancer, the stage of the cancer, the patient's age and general health, and the patient's past history, if any, of cancer treatments. Doctors also look at past cases, medical studies, and clinical trials to determine which chemotherapy drugs should be used. Often, cancers respond better to a combination of drugs, so oncologists look at past combinations that have been successful in similar circumstances.
The appropriate biotherapy to accompany the chemotherapy, if any, depends on the type of cancer. Biotherapy is generally available for lymphoma or breast cancer. The biotherapy agent most commonly given as part of chemotherapy to treat breast cancer is called Herceptin, and the biotherapy for lymphoma is called Rituxan.
Dosage and Scheduling
Doctors consider the appropriate dosages of chemotherapy and the schedules for administering the drug. Chemotherapy drugs are very strong and can have many adverse consequences on the body. Lower doses have fewer side effects and can be given with greater frequency over longer periods of time without taxing the body. However, the lower doses may not be as effective at killing cancer cells. Higher doses may be more effective at killing cancer cells but can't be given as frequently because the body needs time to recover between treatments. Cancer cells can grow during the time periods necessary for recovery. These factors must be balanced in order to set a dosage schedule, which may need to be altered if the patient responds poorly to treatment or suffers adverse side effects or the cancer cells continue to grow.
Administration of biotherapy is still largely experimental as of 2009, and according to Danbury Hospital, it may not be readily available as part of a cancer treatment program. As of 2009, Danbury Hospital suggests that the majority of biotherapy is administered as part of clinical trials or research studies.
Selecting a Dosage Method
Chemotherapy can be given orally (in pill form), or applied topically (in the form of cream or lotion). It can be given intravenously or injected into muscles, under the skin or directly into arteries. It can be infused into the cerebrospinal fluid or into the chest cavity, bladder or stomach. Finally, it can be injected directly into the tumor. The method of delivering the treatment depends on the specific drug and/or the specific type of tumor being treated.
Biotherapy is generally administered orally, in pill form.
Safety Guidelines
Chemotherapy drugs can be dangerous to doctors and nurses who come into contact with the medication. They can alter DNA structure or cells, potentially put people at risk for certain types of cancers, interfere with fetal development in pregnant women, and irritate the skin. Doctors and nurses handling chemotherapy medications or administering this biotherapy need to use precautions to avoid contact with the drugs, including wearing gloves, gowns and goggles. They should take precautions to avoid accidentally inhaling the drugs when preparing the dosage. Finally, because urine and stool from a cancer patient can contain chemotherapy drugs, special precautions should be taken by health care professionals who are handling these wastes for any reason.
Doctors are still not fully sure of the effects of biotherapy, however,the National Cancer Institute does not caution against any adverse side effects from coming into contact with biotherapy agents.
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