Chemotherapy is normally given in cycles, most commonly three to four weeks apart, to a total of four to six months. Between cycles your body's normal cells recover (blue line) but the tumour cells do not (red line). Over the entire chemotherapy course its hoped that the tumour cells would have been destroyed, leaving the body a little battered but intact.

In most cases, the exact dose of chemotherapy given to you is calculated by measuring your height and weight, then working out your surface area. In this way, treatment is individualised for each patient. These doses of chemotherapy may be modified during the whole course of treatment, based on your reaction to treatment, lifestyle and further blood and urine tests.

Chemotherapy can be given in the form of oral tablets, or as a liquid injected into a vein in your arm using a device  known as an intravenous cannula. Alternatively, it can be injected into a larger vein in the front of your chest via an apparatus called a central line. Central lines are permanent catheters introduced into a large vein before the start of chemotherapy, which avoids you having to have a new cannula for each course. Also it allows you to have blood taken without additional injections. (central lines)

Most chemotherapy drugs are given as an outpatient. Sometimes the drugs have to be preceded by intravenous fluids, and this has to be given as an inpatient staying usually one or two nights. An alternative way of administering chemotherapy is with a continuous infusion pump. In this situation, a drug is carried in a cassette and infused continuously into a central line, while the individual is able to be fully mobile at home or work.

The three main reasons why chemotherapy is recommended for some patients

Firstly, there are those who are having adjuvant chemotherapy. This means that they have had a tumour removed with surgery or radiotherapy but chemotherapy is added as an insurance policy to reduce the chance of it returning in another part of the body in the future.

The second category is where chemotherapy aims to cure as the main form of treatment (Radical). This treatment tends to be quite intensive, has to be modified regularly, and is usually associated with quite a lot of side effects.

The third category is where the aim is not to cure, but to control a specific symptom caused by the tumour.  This is sometimes known as palliative treatment. The aim of this treatment is to improve the quality of life; therefore the side effects from the chemotherapy should not outweigh the benefits of shrinking the tumour.

In these latter two categories, your oncologist would require a full re-assessment of your disease after two or three cycles, to check whether chemotherapy is working effectively. If not, the chemotherapy regime could be changed.

The side effects of chemotherapy depend on which drugs, or combination of drugs, are used. Before you start chemotherapy, your oncologist and specialist nurse would have described which side effects you are most likely to experience. A chemotherapy sheet describing your specific drugs and likely side effects can be printed out from this web and should be given to you.

Further general information Your doctors and specialist nurses are in an ideal position to give you relevant information on your disease and treatment as they know your individual circumstances. Cancerbackup has a help line (0808 800 1234) and a prize winning video available in English, Italian, Urdu, Bengali, Gujarati & Hindi explaining Radiotherapy & Chemotherapy. Cancernet.co.uk has over 500 pages describing cancer, its management, practical tips and tool which patients, their carers and their doctors have found helpful during the cancer journey.