Chemotherapy for rectal cancer
Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells.
It’s sometimes given in combination with radiotherapy – this is called chemoradiotherapy.
Early-stage rectal cancer
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Chemotherapy isn’t usually needed for stage 1 rectal cancers that haven’t begun to grow through the muscle wall and aren’t affecting the lymph nodes.
For stage 2 rectal cancers, the risk of the cancer coming back is low, so chemotherapy may not be needed. However, after surgery the cancer will be examined carefully under the microscope. If cancer cells are found in the blood or lymph vessels very close to the cancer, your doctor may recommend chemotherapy. Giving chemotherapy after surgery is known as adjuvant treatment. Its aim is to reduce the risk of the cancer coming back.
You may also be offered chemotherapy as part of a clinical trial. Your cancer specialist will discuss whether chemotherapy will be of any benefit to you if you have stage 2 rectal cancer.
People with stage 3 rectal cancer are usually offered chemotherapy. They may also be offered chemotherapy as part of a research trial.
The main drugs used in the adjuvant treatment of rectal cancer are a combination of the following:
Benefits and disadvantages of adjuvant chemotherapy for early-stage rectal cancer
There are various benefits and risks of having chemotherapy - your doctor can discuss these with you.
Chemotherapy can reduce the chance of the cancer coming back, but it doesn’t guarantee this. It can also sometimes cause side effects that may be unpleasant. To help decide whether adjuvant chemotherapy may be appropriate in your situation, 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.
If the chance of the cancer coming back is not very high, the chemotherapy may only slightly reduce the chance of the cancer returning. However, if the risk is high, the benefit of chemotherapy may be greater. It’s important to discuss the possible risks and benefits of chemotherapy in your particular situation with your doctor.
Adjuvant chemotherapy for rectal cancer is usually given with a drug called 5-fluorouracil (5FU). 5FU is usually given with a vitamin called folinic acid (leucovorin), which makes it more effective. A tablet that works in the same way as 5FU, known as capecitabine (Xeloda®), is sometimes used. Other drugs such as oxaliplatin (Eloxatin®) or irinotecan (Campto®) are often used if the cancer has spread to the lymph nodes close to the rectum. There’s some evidence that chemotherapy is less effective in older people. You and your specialist will discuss whether treatment is appropriate for you.
There are several research trials in the UK looking at different chemotherapy drugs, or combinations of drugs, to treat rectal cancer. Some of these may be given as tablets. You may be asked if you’d like to take part in a research trial.
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Chemotherapy is sometimes given before an operation. This is known as neo-adjuvant chemotherapy. The aim of the treatment is to reduce the size of the cancer, 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 - this is known as chemoradiotherapy.
Chemotherapy for advanced (secondary) cancer of the rectum
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Chemotherapy may also be given when the rectal cancer has spread to another part of the body (secondary or metastatic cancer). Although cancer of the rectum that’s spread to another part of the body can’t usually be cured, treatment with chemotherapy may be recommended by your doctor. The aim of the chemotherapy is to shrink the cancer and reduce symptoms. This can sometimes help to extend life.
The most common place for rectal cancer to spread to is the liver. The next most common place is the lungs.
Chemotherapy may be given to shrink cancers before they are removed from the liver or, more rarely, the lungs. Sometimes drugs called monoclonal antibodies are given in combination with chemotherapy to shrink the tumour before surgery.
Benefits and disadvantages of chemotherapy for advanced cancer of the rectum
There are various benefits and disadvantages of chemotherapy for advanced rectal cancer, and it’s important to discuss these with your cancer specialist.
It isn’t possible to predict whether the chemotherapy will work for a particular person, but if they are fairly fit the treatment is more likely to be effective. It’s also less likely to have side effects than in someone who is unwell when they start treatment.
You don’t have to have chemotherapy treatment unless you want it. If you choose not to, you’ll still be given treatment to help control any symptoms that the cancer causes. This is known as supportive or palliative care. Palliative care can also be given alongside chemotherapy if needed.
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’ve had in the past.
The most commonly used chemotherapy drugs for advanced bowel cancer are:
Common drug combinations are FOLFOX (a combination of folinic acid, fluorouracil and oxaliplatin), which is also used as adjuvant treatment, and FOLFIRI (a combination of folinic acid, fluorouracil and irinotecan).
Several research trials are being carried out to test new drugs for advanced rectal cancer, and to help find the best way of using the current drugs (those mentioned above). You may be asked if you’d like 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 treatment with chemotherapy, you may be given a different type of chemotherapy (known as second-line treatment). Sometimes a third course of chemotherapy (third-line treatment) may 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.
How chemotherapy is given
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Many people are given capsules or tablets, which are swallowed with water.
Some chemotherapy drugs are given by injection into a vein (intravenously). The drugs may be given through a vein in the back of your hand; a plastic line called a central line, in your chest; or a thin tube inserted into a vein in the crook of your arm (a PICC line).
Sometimes chemotherapy can be given continuously through a small portable pump, which is attached to your central or PICC line. A controlled amount of the drug is given into the bloodstream over a period of time. This means that you can go home with the pump, and spend less time in hospital.
You can have intravenous chemotherapy as an outpatient or inpatient, depending on the treatment. If the treatment lasts for only a few hours, it’s usually given as an outpatient.
If your treatment lasts a few days, it’ll usually be given as an inpatient, but it may be possible for you to have it as an outpatient. Your specialist will discuss this with you.
After the treatment, you will usually have a rest period of a few weeks. This allows your body to recover from the side effects of the treatment. The treatment and rest period make up a cycle of treatment. Each cycle usually lasts two or three weeks.
The number of cycles you have may depend on the stage of the cancer and how well it’s responding to the drugs.
You may have a CT scan after you’ve had a number of cycles, depending on your situation. A CT scan takes a series of x-rays to build up a picture of the inside of the body.
Our chemotherapy section discusses the treatment in more detail.