Chemotherapy involves the use of medication that destroys the leukaemia cells. Depending on the type of leukaemia, it can be applied as a single form of medication, although it is more common to combine two or more drugs.
Some cycles of chemotherapy are administered orally but the majority are injected intravenously. For patients who require regular injections through this method it would be necessary to attach a catheter, which consists of a flexible thin tube that is inserted into a large vein, usually in the arm, the thorax, (below the collarbone), or the neck. Through this catheter, all the medication can be administered, removing the inconvenience of repeated injections.
The medications applied intravenously or orally penetrate the blood stream and reach most of the malign cells in the body. However, these methods do not reach the cells that are present in the central nervous system, and are protected by a barrier that consists of a network of blood vessels that filters the blood between the brain and the spinal column. To reach the leukaemia cells that are present in the central nervous system, it is necessary to apply intrathecal chemotherapy, which consists of an injection of anticancer medication directly in the cerebrospinal fluid, usually applied to the lower part of the spinal column. A similar failure to reach leukaemia cells present in the testicles could mean that radiotherapy treatment would be necessary.
Chemotherapy is administered in cycles: a period of treatment followed by a period of recuperation, before another cycle of treatment. Depending on the type of treatment its administration will require hospitalization or could be treated on an outpatient basis, as a day patient, in a consultation at a medical centre or even in the patient's home.
Side effects of chemotherapy
The side effects depend on the type of medication that is administered and as with all treatments; they can vary from person to person. Generally speaking, chemotherapy affects cells in the process of multiplication, which means that it affects the neoplastic cells (which multiply rapidly) and the healthy cells that multiply faster (blood cells, scalp hair follicle cells, and cells of the digestive tract). This explains many of the symptoms experienced by patients receiving chemotherapy: reduced resistance of the organism against infections (due to the lower number of leukocytes), tiredness and malaise (due to the lack of red blood cells -anaemia-), predisposition to bruising and bleeding (due to missing platelets), loss of hair, nausea, vomiting, mouth ulcers and diarrhea. The majority of side effects disappear gradually during the period of rest between cycles of treatment.
Certain anticancer medication can affect the fertility of a patient. In women, periods can be irregular or even disappear, symptoms similar to the menopause such as hot flushes and vaginal dryness. In men, the production of sperm can be affected. Because these affects can be irreversible, men are recommended to freeze and store their sperm before beginning treatment, providing that there is enough time to do so. For children who receive anti-leukaemia treatment, there is a good chance that they will have a normal level of fertility when they reach adulthood. However, in some cases it may be impossible to reproduce, depending on the type of treatment used, the dosage administered, and the age of the patient at the moment of the treatment. Although it is possible to freeze a fertilized egg for use in the future, the technique of freezing the egg and the ovarian tissue is not sufficiently developed to offer this option to a wide range of patients who are undergoing chemotherapy.