Chemotherapy is the medicine used to destroy cancer cells. Chemotherapy drugs work by interfering with the ability of a cancer cell to divide and reproduce itself. Different types or classes of chemotherapy drugs are used to target a cell at different times in its life cycle. Some chemotherapy may act throughout all parts of the life cycle.
The ultimate aim of chemotherapy as a treatment is to cure the child and ensure they maintain a good quality of life. However, the potential of chemotherapy to cure a child with cancer depends on:
- the type of cancer
- the stage of the disease
- whether there is any spread to other parts of the body
- the technology and facilities available at the hospital where the treatment is to be given
- the professional support and skill available. Appropriate professional support and skill is essential to ensure that medication is administered correctly and that side effects of the chemotherapy are monitored and treated accordingly.
Chemotherapy is the principle modality of treatment in childhood leukemia and lymphoma. In solid tumor it is often used before (Neo-adjuvant) to reduce the size of a cancer and after (adjuvant) local treatment (surgery and/or radiotherapy) to prevent spread to distant places.
For some children, the cancer is not curable and chemotherapy may be used to help control symptoms or discomfort. This is known as palliative chemotherapy.
As each class of chemotherapy works in a different way, most treatment regimes (known as protocols) will contain a combination of drugs to achieve the maximum damage or cell kill to the cancer cells. These chemotherapy combinations are given in courses often called blocks of treatment, over a period of time. For example, a child may require chemotherapy every three weeks and this block of chemotherapy may last for five days over a period of months.
The break between each treatment block gives the body time to recover from the damage caused by previous treatment. This damage occurs as the chemotherapy cannot determine healthy cells from cancer cells and will destroy lots of healthy cells in the body. It is this action on healthy cells that cause the side effects of the treatment, known as treatment toxicity.
Administration of chemotherapy Chemotherapy can be given:
- Orally (by mouth)
- Intravenously (via a vein) – often through a central venous access device
- Subcutaneously (under the skin into subcutaneous tissue)
- Intrathecally (via the cerebral spinal fluid)
- Intramuscularly (into the muscle)
Treatment toxicity (side effects)
Due to the effects of damage on all healthy cells by chemotherapy, children who have had treatment can present with diverse side effects. Below we list the most common side effects.
Gastrointestinal side effects:
- Musositis – the lining of the mouth and gastrointestinal tract becomes inflamed
- Taste alteration – as a result of some drugs taste may be altered
- Nausea and vomiting – may be immediate or delayed and can also be anticipatory
- Loss of appetite
- Weight loss
- Alteration from normal bowel movement e.g. constipation/diarrhoea
- Metabolic disturbances
Haematological side effects:
- Risk of viral infections.