Chemotherapy with Cytotoxic Drugs

What is chemotherapy?

Chemotherapy literally means 'drug treatment'. However, the term chemotherapy has come to mean a treatment of cancer by using anti-cancer drugs called cytotoxic drugs.

There are other types of anti-cancer drugs. For example: drugs which block the effects of certain hormones are used to treat some cancers; monoclonal antibodies and other types of drugs which affect the immune system are used to treat certain cancers. These other types of anti-cancer drugs are not dealt with further in this leaflet.

What are cytotoxic drugs and how do they work?

Cytotoxic drugs are toxic (poisonous) to cancer cells. They kill cancer cells or stop them from multiplying. Different cytotoxic drugs do this in different ways. However, they all tend to work by interfering with some aspect of how the cells divide and multiply. For example, some work by affecting the genetic material of the cell directly, others work by blocking cells from using nutrients needed to divide and multiply.

Two or more cytotoxic drugs are often used in a course of chemotherapy, each with a different way of working. This may give a better chance of success than using only one.

There are many different cytotoxic drugs used in the treatment of cancer. In each case the one (or ones) chosen depend on the type and stage of your cancer. Research continues to find new drugs, and better drug combinations. Your doctor will advise the best treatment for your type of cancer based on evidence from the most recent research trials.

Cytotoxic drugs work best in cancers where the cancer cells are rapidly dividing and multiplying. Most normal cells in the body such as muscle cells, heart cells, brain cells, and bone cells do not divide and multiply very often. They are not usually much affected by cytotoxic drugs.

However, some normal cells in the body divide and multiply quite rapidly. For example, hair cells, bone marrow cells, and cells lining the mouth and gut. These may be affected by cytotoxic drugs and lead to side-effects (see below). As a general rule, normal cells can renew themselves much better than cancer cells and then can usually recover quite well following treatment.

What are the aims of chemotherapy?

Chemotherapy and other treatments may aim to cure the cancer

A cure is the aim in many cases. Some cancers can be cured with chemotherapy alone. Sometimes chemotherapy is used in addition to another main treatment. For example, you may have surgery to remove a tumour but you may also be given a course of chemotherapy after the surgery. This aims to kill any cancer cells which may have spread away from the primary tumour site. Unless treated, these may have developed into tumours at a later time.

Chemotherapy given after a main treatment such as surgery is called adjuvant chemotherapy. Sometimes, chemotherapy is given before surgery or radiotherapy so that these other treatments are likely to work better. Chemotherapy given before another treatment is called 'neoadjuvant chemotherapy'.

Doctors tend to use the word 'remission' rather than the word 'cured'. Remission means there is no evidence of cancer following treatment. If you are 'in remission', you may be cured. However, in some cases a cancer returns months or years later. This is why some doctors are reluctant to use the word cured.

Chemotherapy and other treatments may aim to control the cancer

If a cure is not realistic, with treatment it is often possible limit the growth or spread of the cancer so that it progresses less rapidly. This may keep you free of symptoms for some time.

Chemotherapy may be used to ease symptoms

This is called 'palliative' chemotherapy. Even if a cure is not possible and the outlook is poor, a course of chemotherapy may be used to reduce the size of a cancer. This may ease symptoms such as pain or pressure symptoms from a tumour.

How is chemotherapy given?

The drugs usually need to get into the bloodstream to get to all areas of the body to reach any cancerous cell which may be present.

Intravenous chemotherapy

To get straight into the bloodstream, many cytotoxic drugs are given by injection directly into a vein ('intravenous' injection).

• Sometimes each dose of drug is just injected into a vein from a syringe and needle.
• Some drugs are put into a bag of fluid which then 'drips' into a vein through a small, thin plastic tube which is inserted into a vein in your arm or hand. This method allows the drugs to be diluted and they are less likely to irritate the vein as they get into the bloodstream. It may take several hours for a dose to 'drip' into the bloodstream. Small pumps are often used to make sure the solution 'drips' into the vein at exactly the correct rate.
• In some cases a longer thin plastic tube is placed into a deeper vein. This can be a central line in a vein in your chest or a peripheral line in your arm (sometimes called a PICC line). It can be left in place for months until the course of treatment is finished. This means you do not need repeated injections. Drugs can be injected or 'dripped' through the line from time to time when a dose is due. This method of giving chemotherapy is being used more and more. You can also have blood samples taken via the line (which are often needed for testing during a course of chemotherapy treatment). Special care is needed to keep the line clean and free from blockage and infection.
• Sometimes a prolonged infusion of a drug is given via a line over many days or even weeks.

Chemotherapy given by mouth

Some chemotherapy drugs can be taken as tablets or liquids by mouth and are absorbed into the bloodstream from the gut.

Other methods

Drugs usually do not get into the brain or spinal cord very well from the bloodstream. Therefore, to treat some cancers of the brain or spinal cord, drugs are sometimes injected directly into the fluid which surrounds the brain and spinal cord. This is done by a 'lumbar puncture' when a needle is inserted into the space next to the spinal cord in the lower back.

In certain situations cytotoxic drugs may be given by injection into a muscle; as a cream which is rubbed onto skin; injected into the chest cavity, or even injected directly into a cancerous tumour.

How long is a course of chemotherapy treatment?

Usually a course of chemotherapy is given in 'cycles'. A cycle is a spell of treatment followed by a rest from treatment. For example, you may have a dose of your drug(s) on one day, or several doses over a few days. You may then have a rest from treatment for 3-4 weeks. This allows your body to recover from any side-effects and gives a chance for damaged, normal cells to recover before the next spell of treatment. Treatment cycles are commonly every 3-4 weeks, but vary depending on the cancer being treated and the drugs used.

The length of a full course of treatment is often about six months. So this may consist of about six cycles of treatment over the six months. However, a full course of treatment can vary and may be shorter or longer than six months, and consist of fewer or more cycles.

You may have tests such as scans or x-rays at various times to see how well the treatment is working. These can help to guide a doctor as to how long to continue treatment or even to change the drugs used if the treatment does not seem to be working. You will also have regular blood tests to check on your blood count (see below) and may also have other blood tests to check that your liver and kidneys continue to work well and are not being affected by the drugs.

Where is chemotherapy given?

Most people have chemotherapy treatment as an out-patient. You may have to spend a few hours at hospital for each dose of treatment. Some treatment cycles require a day or so in hospital as an in-patient.

Some people have some of their chemotherapy treatment at home. They have a line inserted into a vein as described above and wear a small portable device to gently pump a drug solution into the line over a set period of time.

What about risks and side-effects from chemotherapy?

Cytotoxic drugs are powerful and often cause unwanted side-effects. Cytotoxic drugs work by killing cells which are dividing and so some normal cells are damaged too. However, side-effects vary from drug to drug. Even with the same drug, different people can react differently. Some people develop more severe side-effects than others who take the same drug. Sometimes, if side-effects are particularly severe, a change to a different drug may be an option.

Some of the most common and important side-effects are listed below. Other side-effects can occur. Your doctor or chemotherapy nurse will be able to discuss with you the likely side effects you may experience with the particular drug (or drugs) you will be receiving. Also, you can read a full list of possible side-effects of any drug on the leaflet from the drug manufacturer. This usually comes in the packaging with the drug and is also available on the internet at www.medicines.org.uk or www.macmillan.org.uk the Macmillan Cancer Support website.

At the end of this section there is a 'checklist' of symptoms which you should report straight away to a doctor if they occur whilst you are on a course of chemotherapy.

Tiredness

Tiredness (fatigue) is a common side-effect. It is likely that you will feel more tired than normal during a course of chemotherapy. You may need to cut back on your normal activities, plan regular rests, and if possible, take some regular light exercise. Some people feel overwhelmingly tired and may need to rely on other people to do routine daily chores.

Nausea and vomiting

It can be common to feel sick (nausea) during and after each cycle of treatment. Try to drink plenty of fluids even if you do not feel like it, to prevent dehydration. Sucking ice cubes is one tip to increase your fluid intake.

Anti-sickness medication will usually help and is commonly taken at the same time as, or just before, a cycle of chemotherapy. There are different types of anti-sickness medication. If one does not work well, a change to a different one may work better.

Effects on the blood and immune system

Cytotoxic drugs can affect the bone marrow. The bone marrow is where you make red blood cells, white blood cells and platelets. Problems which may occur include:

• Anaemia. This means a low level of red blood cells. If you develop anaemia you will feel tired and look pale. You may need a blood transfusion.
• Serious infection. You are more prone to infection if the level of white blood cells goes down too low. (You have less ability to fight off bacteria, viruses and other germs.) See a doctor straight away if you develop signs of infection such as fever or a sore throat. As you have a reduced capacity to fight infection you may be given a high dose of antibiotics directly into your bloodstream if you develop an infection.
• Bleeding problems. Platelets help the blood to clot when we cut ourselves. If the number of platelets in your blood goes down you may bruise easily and bleed for longer than usual after cuts. See a doctor urgently if you notice these symptoms. You may require a platelet transfusion if your platelet level goes very low.

Prior to each cycle of treatment, it is usual to have a blood test to check on your 'blood count'. This checks the level of your red blood cells, white blood cells and platelets. If any of these are too low, then a treatment cycle may be delayed, the choice of drugs may be altered or you may be given treatment to boost the levels of these blood constituents.

Mouth problems

The cells which line the mouth are affected by some cytotoxic drugs. This may lead to a sore mouth, a dry mouth or other mouth problems. Routine good mouth care will help to prevent mouth problems from developing or from becoming more serious. If possible, do the following either yourself or with the help of a carer:

• Brush your teeth twice a day with a soft toothbrush and fluoride-containing toothpaste.
• Rinse your mouth after meals and at night. Use water or 0.9% sodium chloride solution (saline or salt water). You can make a fresh sodium chloride solution for each rinse by dissolving half a teaspoon of salt in 250 ml fresh water. Use cool or warm water, whatever your prefer.
• Remove any debris that you can see in your mouth or on your tongue by gentle brushing with a soft toothbrush. If possible, do this regularly but mainly after meals and at bedtime. Foam sticks are an alternative if brushing with a soft toothbrush causes pain or bleeding.
• Chewing pineapple may also help to clean your mouth. Pineapple contains ananase which is an enzyme (chemical) that can help to break down debris in the mouth. You can use fresh pineapple or unsweetened tinned pineapple.
• Remove dentures at night. Clean dentures with a soft toothbrush and toothpaste. Soak overnight in a denture solution. Rinse before use the next day.

If you develop a dry mouth then simple measures such as frequent sips of water and chewing sugar-free gum will often help and be all that is needed in many cases. Artificial saliva or medication to stimulate the salivary glands are sometimes used, which your doctor can prescribe for you. (See separate leaflets called 'Mouth Care' and 'Dry Mouth' for more details.)

Hair loss

Some cytotoxic drugs damage the hair making cells. Some or all of your hair may fall out. This usually occurs 2-3 weeks after a course of treatment starts. Body hair and eyelashes may also fall out in addition to scalp hair. After the course of treatment has finished the hair will usually regrow within 4-12 months.

Hair loss does not bother some people. You may wish to cut your hair short before starting chemotherapy so that any changes are not so dramatic. Some people like to wear a wig. Other people prefer to wear a hat or scarf. In particular, remember to cover your head or wear high protection sun screen when out in the sun. If your eyelashes fall out, you can wear glasses or sunglasses to protect your eyes on windy days.

Constipation

This may be helped by eating plenty of foods high in fibre and having lots to drink. A laxative may be needed in some cases.

Diarrhoea

This is a side-effect from some drugs. You should increase the amount that you drink if you develop diarrhoea. If it persists or becomes severe, you should tell your doctor. Anti-diarrhoea medicines may be needed and you may even need to be admitted to hospital for a 'drip of fluid' if you become dehydrated due to severe diarrhoea.

Nerve problems

Some drugs can affect nerves. This may lead to a lack of sensation in parts of the body such as the fingers or toes, pins and needles or weakness of muscles. Tell your doctor if any of these symptoms occur.

Fertility

Some chemotherapy drugs can affect fertility in both men and women. Sometimes this is temporary and sometimes it is permanent. If this is a concern, one option may be for men to store sperm or women to store ova (eggs) before chemotherapy treatment begins. These can be 'frozen' and may be able to be used in the future if you wish to have a pregnancy. Some women develop an early menopause when taking some cytotoxic drugs.

Summary about side effects and checklist

You should discuss with your doctor the particular risks and concerns for the drugs which are used in your own treatment. As a general 'checklist', whilst you are going through a course of chemotherapy, see your doctor as soon as possible if you:

• Develop a fever (high temperature) or sweats.
• Develop other symptoms which may be due to an infection. For example, a sore throat, pain on passing urine, a cough, breathlessness or the skin around a line site (if you have one inserted) becomes red or sore.
• Develop easy bruising, bleed easily or have any abnormal bleeding.
• Have persistent or severe vomiting, particularly if you cannot keep fluids down.
• develop constipation or diarrhoea.
• have other symptoms which are affecting you.

Some other points about chemotherapy

Before starting chemotherapy

Depending on the drugs used, you may have a number of 'baseline' blood tests to check that your liver and kidneys are working well. You may also have a heart check (an ECG and/or echocardiogram) and a check on your lung function. This is because some drugs may affect these organs. These tests may be repeated during treatment to check that these organs continue to work well.

Pregnancy and contraception

Although some cytotoxic drugs can reduce fertility, pregnancy is still possible if you are sexually active. However, cytotoxic drugs can damage sperm, ova and an unborn baby. Therefore, it is not advisable to become pregnant if you are a female who is having chemotherapy or a female partner of a male who is having chemotherapy. If you are sexually active you should use reliable contraception.

Check with your doctor how long to continue contraception for after treatment is finished.

Chemotherapy and later cancer

There is a very small risk that cytotoxic drugs may cause another form of cancer much later in your life.

Some cytotoxic drugs can:

• Interfere or react with other medicines. Check with your doctor about any other medicines that you take.
• Be affected by alcohol. Check with your doctor if you can drink alcohol with your treatment.
• Make you dizzy or too ill to drive. It is usually best not to drive yourself to and from hospital for chemotherapy treatment.

If you have any concerns about your treatment

Do not hesitate to ask your doctor or nurse for help and advice.

Further help and information

Macmillan Cancer Support

Tel: 0808 800 1234 Web: www.macmillan.org.uk
Provide information and support to anyone affected by cancer. They have very detailed information on the various drugs used as chemotherapy.

Cancer Research UK

Web: www.cancerhelp.org.uk provides facts about cancer including treatment choices.

Other support groups

A list of the many self help and support groups for cancer patients, their families, carers and friends can be found at: www.patient.co.uk