Chemotherapy is the use of special anti-cancer (cytotoxic) drugs to destroy cancer cells.
Early-stage bowel cancer
In the treatment of early-stage colorectal cancer, chemotherapy, if needed, is mainly used after surgery. The aim is to reduce the risk of the cancer coming back: this is known as adjuvant treatment. Chemotherapy often isn’t needed for very early-stage colorectal cancers, that haven’t begun to grow through the muscle wall and aren’t affecting the lymph nodes (Dukes A).
Chemotherapy is occasionally given before surgery to treat rectal cancers; this is known as neo-adjuvant chemotherapy. Radiotherapy may be given at the same time as chemotherapy; this is called neo-adjuvant or pre-operative chemoradiotherapy.
The main drug used is 5-fluorouracil (5FU).
Neo-adjuvant chemotherapy is mainly given to treat cancers affecting the rectum. The aim of the treatment is to reduce the size of the tumour, to make it easier to remove during surgery. This may make it possible to avoid having a permanent colostomy. Sometimes the chemotherapy is given in combination with radiotherapy.
After surgery, when the cancer has been removed and examined carefully under the microscope, your doctor may recommend that you have chemotherapy. This is called adjuvant chemotherapy. Its aim is to get rid of any remaining cancer cells that could have been left behind, and reduce the chance of the cancer coming back in the future.
There are various benefits and risks of having chemotherapy and your doctor can discuss these with you. The chemotherapy can reduce the chance of the cancer coming back, but does not guarantee this. It can also sometimes cause side effects that may be unpleasant. To help decide whether adjuvant chemotherapy may be appropriate in your case, your specialist will take into account the risk of any cancer cells being left behind, the likelihood that the chemotherapy will get rid of them, and the possible side effects of the treatment.
Pros and cons of chemotherapy for early-stage cancer
If the chance of the cancer coming back is low, the chemotherapy may only slightly reduce the chance of the cancer returning. However, if the risk of the cancer coming back is high, the chemotherapy can greatly reduce the chance of the cancer returning.
It is important to discuss with your doctor the possible risks and benefits of chemotherapy in your particular situation. This will allow you to compare the possible benefits and side effects, and decide whether or not to have treatment.
Adjuvant chemotherapy for bowel cancer is usually with a chemotherapy drug called 5-fluorouracil (5FU). 5FU is usually given with a vitamin called folinic acid (leucovorin), which makes it more effective. There are several different ways of giving this chemotherapy. A tablet form of 5FU, known as capecitabine (Xeloda®), is sometimes used.
Other drugs such as oxaliplatin (Eloxatin®) are also frequently used if the cancer has spread to the lymph nodes close to the bowel – Dukes C. Your specialist will discuss your particular course of treatment with you.
There are several research trials in the UK looking at different chemotherapy drugs, or combinations of drugs, to treat bowel cancer. Some of these may be given as tablets. You may be asked to take part in a research trial to test one of these treatments.
Advanced (secondary) bowel cancer
Chemotherapy may also be given when the cancer has spread to another part of the body (secondary or advanced cancer). Many people have no further problems after their original treatment for cancer of the large bowel, but unfortunately in some people the cancer comes back or spreads to other parts of the body. This is called secondary (or metastatic) cancer of the large bowel. Sometimes, when the cancer is first diagnosed, it may already have spread beyond the bowel. The most common place for cancer of the bowel to spread to is the liver. The next most common place is the lungs.
Although secondary cancer of the large bowel can’t usually be cured, treatment with chemotherapy may be recommended by your doctor. The aim of the chemotherapy is to shrink the tumours and reduce symptoms. This can sometimes help to prolong life. Chemotherapy may be given to shrink tumours before they are removed from the liver or, more rarely, the lungs. Sometimes drugs called monoclonal antibodies are given in combination with chemotherapy.
Improvements in surgical techniques combined with drug treatment have meant that some people who have had removal of liver secondaries, often combined with drug treatment, appear to be cured as a result of their treatment. Your doctor or specialist nurse can discuss this with you further.
Benefits and disadvantages
There are various benefits and disadvantages of chemotherapy for advanced bowel cancer, and it is important to discuss these with your cancer specialist.
It is not possible to predict whether the chemotherapy will work for a particular person, but if a person is fairly fit the treatment is more likely to be effective. It is also less likely to have side effects, than in someone who is unwell when they start the treatment.
If you do not want to have chemotherapy treatment, you can be given medicines to help control any symptoms that the cancer causes. This is known as supportive, or palliative, care.
Your doctor will consider a number of things before asking you to make a decision about particular treatments. This will include where the secondary cancer is, your general health, and any chemotherapy treatment you have had in the past.
The most commonly used chemotherapy drugs for advanced bowel cancer are:
Several research trials are being carried out to test new drugs for advanced colorectal cancer, and to help find the best way of using the current drugs (those mentioned above). You may be asked to take part in a research trial using new chemotherapy drugs or new types of treatments.
If the cancer starts to grow again, during or after the chemotherapy, you may be given a different type of chemotherapy (this is known as second-line treatment). Sometimes third-line chemotherapy may also be given.
If you have advanced cancer, there are many difficult issues to deal with and you may find it helpful to read our section on coping with advanced cancer.
Our sections on controlling cancer pain and controlling cancer symptoms explain ways that pain and symptoms can be controlled. They also give information on the type of support that is available from health professionals and other sources.
How chemotherapy is given
Some chemotherapy drugs are given as capsules or tablets. These are swallowed with water.
Most people with colorectal cancer will have their chemotherapy drugs given by injection into a vein (intravenously). The drugs may be given through a plastic line, called a central line, in your chest; or through a thin tube inserted into a vein in the crook of your arm (known as a PICC line ).
Position of a central line
PICC – the tube is threaded thorugh the vein until the end is near your heart
Sometimes chemotherapy can be given to you through a small portable pump, the size of a small music player. The pump is attached to your central or PICC line. A controlled amount of the drug can be given into the bloodstream over a period of time. This means that you can go home with the pump, and so spend less time in hospital. Some people whose cancer has spread to the liver may be given chemotherapy into an artery that goes directly into the liver.
Chemotherapy into a vein in the arm, or through a central or PICC line, can be given as a session of treatment. A session may last from a few hours to several days. If you have treatment for a few hours, this may be repeated each week for several months. This chemotherapy is usually given as an outpatient (at a hospital, but without you having to stay overnight).
If your treatment lasts a few days you will usually have a rest period of a few weeks before the next session. This allows your body to recover from the side effects of the treatment. The chemotherapy session and the rest period make up a cycle of treatment. You may need to stay in hospital for your treatment, but it can also often be given to you as an outpatient. Your specialist will discuss this with you.
Chemotherapy can sometimes cause unpleasant side effects, but if your cancer is causing symptoms it can also make you feel better by relieving them. Most people have some side effects, but these can usually be well controlled with medicines. Common problems are described here, along with some ways of reducing them.
Reduced resistance to infection
While the drugs are acting on the cancer cells in your body, they may also temporarily reduce the number of normal white blood cells. When these cells are reduced you are more likely to get an infection. While your level of white blood cells is low, it is important to avoid crowded places, where you may come into contact with infection, and to avoid anyone who already has an infection, such as a cold or flu.
It is important to contact your doctor or the hospital straightaway if you have any signs of infection, such as a high temperature (above 38ºC or 100.5ºF), or if you suddenly feel unwell (even with a normal temperature). During chemotherapy your blood will be tested regularly and, if necessary, you will be given antibiotics to treat any infection.
You are likely to find that you become very tired and have to take things much more slowly. Just do as much as you feel like and try not to overdo it.
Some of the drugs may make you feel sick (nauseated) and possibly be sick (vomit). There are very effective anti-sickness drugs (anti-emetics) to prevent or reduce nausea and vomiting. Your doctor will prescribe these for you. Let your doctor or nurse know if your anti-sickness drugs are not helping you, as there are several different types you can take.
Some of the chemotherapy drugs used to treat bowel cancer can cause diarrhoea. This often starts several days after the treatment. If you are taking chemotherapy tablets or capsules at home, it is important that you let your doctor or nurse know if you have diarrhoea, as your treatment may need to be stopped.
If you have diarrhoea your doctor can give you medicine to reduce this and slow down the bowel. You may also be able to help control it by eating a low-fibre diet. Our section on diet and cancer has useful advice on this.
If you have had a colostomy or ileostomy, it may be more difficult to cope with diarrhoea caused by the chemotherapy. Your stoma nurse or cancer specialist can give you advice and support. Some people find that they need to make sure they are close to a toilet during the course of their treatment and for a while afterwards. This can be very frustrating, but usually improves gradually a few weeks after the treatment has ended. If the diarrhoea continues after this time it is important to talk to your cancer specialist or stoma nurse, so that they can help you find ways of overcoming the diarrhoea.
You may find that you get a sore mouth and mouth ulcers while having chemotherapy. Keeping your mouth clean with regular mouthwashes is important. Your nurse will show you how to use these properly. If a sore mouth makes eating difficult, you can try replacing meals with nutritious drinks.
Ask your doctor if the drugs you are taking are likely to make your hair fall out. Most drugs used to treat bowel cancer do not, but some may make your hair thin. If your hair does fall out, it will start to grow back again once your treatment is over.
Soreness of hands and feet
If 5FU or capecitabine are given over a long period of time or are given continuously through a pump, soreness and redness of your palms and the soles of your feet can occur. This is known as hand/foot syndrome or palmar-plantar syndrome. Vitamin B6 may be prescribed to help to reduce this side effect and non-perfumed moisturising creams can often help to relieve the symptoms. If the symptoms are very severe your doctor may reduce the dose of the chemotherapy or give you a short break from it.
Numbness or tingling
Oxaliplatin can affect the nerve endings and cause numbness, burning or tingling in the hands, feet, neck or throat (known as peripheral neuropathy ). You may also find it hard to do up buttons etc. The numbness or tingling may not happen with the first treatment. If it occurs, it should gradually disappear once the treatment has finished.
Sometimes in the first few days after oxaliplatin is given, these side effects can be triggered by anything cold, such as cold drinks or washing water, but often they only last for a few minutes.
Although they may be hard to bear at the time, these side effects gradually disappear once your treatment is over, although for some people this can take some months. Tell your doctor if you have side effects, as many can be eased with medicine.
It is not advisable to become pregnant or father a child while taking any of the chemotherapy drugs used to treat colorectal cancer, as they may harm the developing foetus. It is important to use effective contraception during your treatment and for a year afterwards. You can discuss this with your doctor or specialist nurse.
Condoms should be used during sex within the first 48 hours after chemotherapy to protect your partner from any of the drug that may be present in semen or vaginal fluid.