Chemotherapy

The word chemotherapy stems from the Greek 'chemo' meaning chemical, and 'therapy' meaning treatment.

Chemotherapy involves the use of drugs to destroy or control the growth of malignant cells. It can be given as a single drug or a combination of drugs. The type of disease a person has will determine the type of treatment, if any, that is recommended by their haematologist.

The chemotherapy drugs can be given by: 

* Mouth (oral) - as tablets or capsules 
* Subcutaneous (SC) - by injection through the skin
* Intravenous (IV) - by injection into a vein. This may be done via a specially implanted catheter.  Common types of these catheters include portacaths, groshong catheters, hickman catheters or PICC lines 
* Intrathecal (IT) - by injection into the cerebro/spinal fluid

Usually, no pain is experienced when treatment is given, apart from a possible needle sting if drugs are administered by injection.

The drugs must circulate in the blood stream to reach the abnormal cells. Tablets or capsules reach the blood stream by absorption through the lining of the gut, just like food. If a drug is given into a vein it enters the blood stream immediately. If the drugs are given by an injection through, or under, the skin they are absorbed more slowly into the blood stream from the subcutaneous tissue. Once in the blood stream, the drugs are distributed to all parts of the body.

Possible side effects

Many of the drugs used to treat leukaemia and other related blood conditions may cause side effects, which can vary greatly in each person. Advances in research aim to minimise these or prevent them completely.

Chemotherapy drugs work in different ways, but generally aim to interfere with abnormal cell duplication and/or encourage abnormal cells to die. Rapidly dividing malignant cells are very sensitive to this treatment, as are normal bone marrow cells which duplicate rapidly to maintain blood production.

Normal cells that may be affected include:

* Bone marrow
* Gastro-intestinal tract (mouth, stomach, and intestines)
* Hair follicles

However, normal cells do have the capacity to regenerate and while hair loss is more slowly replaced, cells in the gastro intestinal tract and bone marrow grow back relatively quickly.

Bone marrow
Bone marrow is the place where the body manufactures blood cells:

* White blood cells combat infection
* Red blood cells prevent anaemia and allow the blood to transport oxygen to the tissues
* Platelets help to clot blood and promote healing of breaks in the skin

Following chemotherapy, growth of normal bone marrow cells may be temporarily affected, resulting in anaemia, infection and bleeding. Regular blood tests may be necessary to watch for the onset of these side effects.

Gastro-intestinal
Because normal cells in the intestinal tract (mouth, stomach and intestines) are destroyed by the drugs, people receiving chemotherapy can experience the following:

* Nausea, vomiting and loss of appetite
* Mouth ulcers and pain when swallowing
* Loose and frequent bowel motions
* Constipation
* Taste alteration

There are treatments available to reduce or control some of the symptoms.

Hair
Temporary hair loss (including body hair) is common, but not universal, with some drugs. Hair almost always grows back when chemotherapy ceases.

Fertility
Chemotherapy can make males and females infertile. However, there are cases of patients going on to have children successfully and such options should be discussed with a haematologist.

It is not advisable for couples to try to get pregnant whilst either partner is undergoing treatment due to the possible highly toxic effects on the baby. Contraception is strongly advised during this time.

Delayed effects
In long-term survivors there is an increased risk of other cancers for a time, possibly as a result of the treatment. This needs to be discussed with a haematologist.