Chemotherapy
- How does it work?
- How is Chemotherapy given?
- Short term effects of treatment on Care & Mobility needs
How does it work?
Chemotherapy is treatment of cancer with drugs that kill cancer cells.
Normal cells in the body are constantly dying and being replaced by new normal cells. New cells are made by a process called cellular proliferation. Before dividing, a cell makes a new set of chromosomes out of Deoxyribonucleic Acid (DNA) so that there are two copies of the chromosomes in the cell. These two copies separate from each other to create two complete sets of chromosomes, this process is called mitosis. Then the whole cell divides into two, forming two new cells with one complete set of chromosomes each. This is called cell division. Most normal cells in most tissues are in a resting phase rather than a ‘division’ or ‘mitosis phase’. Cell division is controlled to allow cell renewal to happen at a constant rate; to the naked eye tissues look the same over time.
In cancer there is a loss of accurate control of cell division. This leads to abnormal production of new cells which disobey normal growth signals. To the naked eye we see new growths or tumours which are large colonies of abnormally growing cells. Chemotherapeutic drugs interfere with cellular processes of division, progression of the cell cycle from the resting to division phase and the process of making DNA. Because cancer cells undergo these processes more frequently than normal cells they are more susceptible to damage by these drugs.
How is Chemotherapy given?
Most chemotherapy is given into a vein via a drip. Rarely it may be given into an artery (intra-arterial chemotherapy) or into fluid surrounding the spinal cord (intrathecal chemotherapy) or directly into the abdominal cavity (intraperitoneal chemotherapy)., Different drugs are used for different types of cancer and may be given at different intervals over shorter or longer periods of time - from a one off treatment to several years of regular treatment.
A course of chemotherapy usually lasts 3-6 months with treatments given as an out-patient every few weeks. The gap between treatments enables the normal cells such as the bone marrow and cells lining the gut time to return to normal. The side effects may be very severe for several days around the treatment but people may be able to function normally in-between. They may feel tired for most of the time. Some people may feel extremely unwell throughout the whole period.
Chemotherapy regimes are highly variable between types of cancer and change over time as new drugs and regimes become available. The information for each cancer will give a good indication of how long treatment lasts and what the expected side effects will be. Some people may have treatment via 5 day infusions and others may have treatment programmes extending for 2-3 years. Some chemotherapy drugs are given as tablets.
Some chemotherapy drugs are given via indwelling catheters or ports. These can remain in place for months or years. They are normally put in by Radiologists into large veins in the neck or sometimes the peritoneal cavity and tunnelled under the skin. The end of the catheter may be outside the skin or underneath the skin. Ports under the skin tend to last for longer because there is less chance of them getting infected. Having the tip of the catheter in a large vein in the neck, instead of a small one in the arm means it is less likely to clot off and there is easier access for drugs. Having an indwelling catheter means each treatment is less painful because a drip does not have to be inserted into a vein for each time. The majority of chemotherapy is given for palliative treatment.
Short term effects of treatment with Chemotherapy on Care and Mobility needs
The majority of patients having chemotherapy will have no significant mobility needs and will be self-caring for most of the time during treatment. The exception to this is during treatment of leukaemia. During leukaemia treatment, the white cell count may be low for long periods and there may be a significant risk of picking up infection during normal every day activities. This includes shopping for and preparing food. They may be ‘reverse barrier nursed’ at home. This means they and their families need to take precautions against infection at all times. They will need help with shopping for food and supplies and will need someone around to intervene should they become ill.
