Chemotherapy is the use of cytotoxic (cancer) drugs to treat cancer. It is most commonly delivered into the veins (intravenously) but some can be taken as tablets (orally).
Chemotherapy is usually given for short periods at 2 to 4 week intervals (cycles). The time between cycles is to allow the body to recover from the toxic side-effects on the body. Often a combination of 2-3 drugs are given to achieve the best response.
Side-effects of chemotherapy depend on the drug given, dose and frequency of administration. Common side-effects include nausea and vomiting, mouth ulcers, diarrhoea, hair loss and a low blood count. The blood count can be affected by one or a combination of 3 ways:
- low red blood cells or haemoglobin (anaemia) causes tiredness, pale complexion and breathlessness
- low white blood cells will make the patient more prone to infections
- low platelet count increases the risk of bruising and bleeding
Patient with low white blood cells (neutropenia) may not have any symptoms until an infection develops. The common symptoms of infection (neutropenic sepsis) are fever and rigors (shivers or shakes). There may be more specific symptoms relating to the site of infection such as diarrhoea, cough or cystitis. Any patient on chemotherapy developing symptoms of infection MUST seek appropriate medical help immediately. If they do not there is a serious risk of serious complications and even death.
Prior to a decision to proceed with chemotherapy all patients will be fully advised by the oncologist what the risks and benefits of treatment are. Patients will also be given 24 hour access direct contact numbers in the event of an emergency.
Radiotherapy is the use of ionising radiation, otherwise known as X rays for treatment of cancer. It is usually delivered using a machine known as a linear accelerator, which directs high energy radiation through the body to the target area.
The first visit to the radiotherapy department is for treatment planning on a machine called a CT simulator. The patient is positioned carefully on the couch by the radiographers (radiotherapy technicians) and a CT scan is taken through the region of the body to be treated. Several marks and permanent tattoos are placed on the skin in order for the same position to be reproduced on the linear accelerator for treatment.
The treatment area (target volume) is determined by the cancer specialist (clinical oncologist) and the optimal way of delivering the treatment is planned by the physicists.
Radiotherapy works by causing damage to the DNA (genetic code) of cancer cells but can also affect normal tissue cells. If higher doses of radiotherapy are to be used, this is usually divided into multiple smaller treatments (fractions) in order to minimize unwanted side-effects. A typical course of radiotherapy can take 4-6 weeks to deliver.
The radiotherapy treatment usually takes 10-15 minutes to deliver and during treatment the patient does not feel anything. Side-effects can be of acute or late onset and depend on the area which is treated as well as the dose delivered. Acute side-effects occur immediately or soon afterwards and commonly include tiredness, nausea, diarrhoea and sore skin. Late side-effects are less common and are usually not apparent for at least 6 months after completion of radiotherapy but tend to be permanent and often progressive.
Patients will be fully advised by the clinical oncologist what the risks and benefits of the radiotherapy are before a decision is made to proceed. When planning the radiotherapy treatment, the greatest care will be taken to balance achieving the most benefit against minimizing the risk of late side-effects.
When chemotherapy is given at the same time as radiotherapy (synchronous chemoradiotherapy) in many cancers, there is a radiosensitisation effect increasing the effectiveness of the treatment. Chemoradiotherapy is routinely used for cancers of the anus, rectum, oesophagus, pancreas, cervix, bladder, head and neck, brain and lung.
Biological Therapies Treatment
Biological therapies are treatments which use a natural substance or a drug developed from a natural substance to modify the function of a cancer cell. There are several types of biological therapies, which include monoclonal antibodies, small molecule inhibitors, vaccines, immune therapies, gene therapies.
The development of new biological therapies is current one of the most exciting areas for cancer research. Scientists are looking for novel ways of interfering with the way a cancer cell functions without causing significant side-effects on the rest of the body
Over recent years there has been rapid expansion of numbers of licensed biological therapies for cancers including bowel, breast, lymphoma, leukaemia, kidney and gastrointestinal stromal tumours (GIST). Many more biological therapies remain under clinical trial development.