Cancer is the result of cells within the body developing genetic mutations that cause them to grow abnormally quickly and invade other tissues. Chemotherapy is one treatment approach that can be used when a cancer cannot be surgically removed or as an addition to surgical removal of the cancerous cells. Chemotherapy describes a broad range of treatments that can be used for most kinds of cancer.
Principles
As Kids Health explains, the purpose of chemotherapy is to kill cancer cells throughout the body. Chemotherapy works by poisoning these rapidly dividing cancer cells. Unlike other treatments for cancer, chemotherapy affects cancer cells anywhere in the body.
Administration
Chemotherapy is most often given intravenously. Typically, the medication is slowly infused using an IV and a bag that holds the chemotherapy solution. Sometimes a permanent IV, also known as a catheter, is put in the patient's vein for easier access. Some forms of chemotherapy can be taken orally (either as a tablet or liquid) or injected into the patient's muscles or spinal fluid.
Types
According to the American Cancer Society, chemotherapy drugs can be broken down into several different classes. Alkylating agents are drugs that directly cause DNA damage to the cancerous cells. Anti-metabolites, on the other hand, interfere with the ability of cancer cells to duplicate their DNA, which keeps the cells from growing. Mitotic inhibitors are chemotherapeutic compounds that also work to prevent cancer cells from dividing. Corticosteroids can also be used to treat some kinds of cancer, including lymphomas and leukemias.
Drug Choice
Usually chemotherapy is administered using multiple medications at the same time. This helps maximize the effectiveness of the treatment, especially if two or more different types of chemotherapy are used. When selecting treatment regimens, doctors have to be mindful of the side effects of the different drugs used; different chemotherapy drugs have differing side effects, and it is important that the side effects of different drugs used in combination do not overlap. Doctors also try to avoid using chemotherapy medications that could interfere with other medications that the patient is taking.
Patient Choice
The "Journal of the American Medical Association" notes that for some patients, chemotherapy is not recommended. This is the case for patients who have limitations as to how well they can take care of themselves. Patients who have limited self-care and spend either the majority or all their time confined to a bed or chair are not good candidates for chemotherapy, as they may have trouble withstanding the side effects. Patients with this level of poor health are also unlikely to receive as much benefit from chemotherapy.
