What is MATRIX?

MATRIX® is a combination treatment used to treat primary CNS lymphoma. It may sometimes be used to harvest stem cells in people having a stem cell transplant. It is best to read this information with our general information about chemotherapy and the type of cancer you have.

Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

The drugs used

MATRIX is named after the initials of the drugs used for this treatment. The drugs are:

Methotrexate, cytarabine and thiotepa are chemotherapy drugs. Rituximab is a type of targeted therapy called a monoclonal antibody. The drugs used in MATRIX can pass through the brain’s natural protection (called the blood-brain barrier) into the brain and spinal cord.

How MATRIX is given

You will be given MATRIX during a stay in hospital. A chemotherapy nurse will give it to you.

During treatment you usually see a cancer doctor, a chemotherapy nurse or a specialist nurse, and a specialist pharmacist. This is who we mean when we mention doctor, nurse or pharmacist in this information.

Before or on the day of treatment, a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that your blood cells are at a safe level to have treatment.

You will see a doctor or nurse before you have treatment. They will ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your chemotherapy. Your nurse will tell you when your treatment is likely to be ready.

Your nurse usually gives you anti-sickness (anti-emetic) drugs before the treatment. The drugs are usually given through:

  • a fine tube that goes under the skin of your chest and into a vein close by (central line)
  • a fine tube that is put into a vein in your arm and goes up into a vein in your chest (PICC line).

Your course of treatment

You usually have a course of several cycles of MATRIX treatment over a few months. Your nurse or doctor will discuss your treatment plan with you.

A cycle of treatment is made up of:

  • the days you are given the chemotherapy and targeted therapy drugs
  • followed by a rest period when you won’t have any drugs. The rest period gives your body time to recover.

Each cycle of MATRIX takes 21 days (3 weeks). You have the chemotherapy and targeted therapy drugs over 5 to 10 days. The time depends on whether you are having MATRIX as your main treatment or to harvest stem cells.

On the days you are having your chemotherapy drugs you will be given a continuous infusion of fluids. The fluids help to reduce the side effects of high dose methotrexate and keeps you hydrated.

Once you have had all the chemotherapy drugs, you have a rest period with no treatment for the remaining days of the 3-week cycle. This completes your first cycle of MATRIX.

At the end of the rest period, you start your second cycle of MATRIX.

About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects. You may get some of the side effects we mention, but you are unlikely to get all of them.

You may also have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) to download a Patient Information Leaflet (PIL) for these drugs. The leaflet lists all known side effects.

Side effects while treatment is being given

Some people may have side effects while they are being given the chemotherapy or shortly after they have it:

Allergic reaction

Some people have an allergic reaction to rituximab while they are having it. A reaction is most likely with the first infusion, so it is given slowly over a few hours. Before treatment, you will be given medicines to help prevent or reduce any reaction.

Signs of a reaction can include:

  • feeling hot or flushed
  • a skin rash
  • itching
  • shivering
  • feeling dizzy
  • a headache
  • feeling breathless
  • swelling of your face or mouth
  • pain in your back, tummy or chest.

Your nurse will check you for signs of a reaction during your infusion. If you feel unwell or have any of these signs, tell them straight away. If you do have a reaction, it can be treated quickly.

Sometimes, a reaction can happen a few hours after treatment. If you develop any signs or feel unwell after you get home, contact the hospital straight away.

Common side effects

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is called neutropenia.

If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have if:

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection.

Symptoms of an infection include:

  • feeling shivery
  • a sore throat
  • a cough
  • diarrhoea
  • needing to pass urine often.

It is important to follow any specific advice your cancer treatment team gives you.

The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time.

G-CSF (granulocyte-colony stimulating factor) is a type of drug called a growth factor. It encourages the body to make more white blood cells.

Your doctor may give you G-CSF:

  • if the number of white blood cells is very low
  • to stop the number of white blood cells getting low.

You have it as a small injection under the skin.

Bruising and bleeding

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. 

Tell your doctor if you have any bruising or bleeding that you cannot explain. This includes:

  • nosebleeds
  • bleeding gums
  • tiny red or purple spots on the skin that may look like a rash.

Some people may need a drip to give them extra platelets. This is called a platelet transfusion.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

Feeling sick

You may feel sick in the first few days of your treatment. The nurses will give you anti-sickness drugs regularly. If you still feel sick, tell your nurse or doctor. They can change the anti-sickness drug to one that works better for you.

Sore mouth

You may get a sore mouth or mouth ulcers. This can make you more likely to get a mouth infection.

Use a soft toothbrush to clean your teeth or dentures in the morning, at night and after meals.

If your mouth is sore:

  • tell your nurse or doctor – they can give you a mouthwash or medicines to help
  • try to drink plenty of fluids
  • avoid alcohol, tobacco, and foods that irritate your mouth.

Changes to your taste

You may get a bitter or metal taste in your mouth. Sucking sugar-free sweets may help with this. Some foods may taste different or have no taste. Try different foods to find out what tastes best to you. Taste changes usually get better after treatment finishes. Your nurse can give you more advice.

Helpful hints to improve taste

  • Season food or add spices and herbs to add flavour when cooking.
  • Use strong, flavoured sauces or gravies to make food tastier.
  • Eat sharp-tasting fresh fruit and juices or try sugar-free sweets to leave a pleasant taste in your mouth.
  • Try cold foods as they may have a stronger taste than hot foods.

Diarrhoea

This treatment may cause severe diarrhoea. Your nurse or doctor may give you anti-diarrhoea drugs to help manage this.

If you have diarrhoea try to:

  • drink at least 2 litres (3½ pints) of fluids each day
  • avoid caffeine, milk products, high-fat foods and high-fibre foods.

Some people may need to have fluids through a drip. Your doctor may prescribe antibiotics.

Loss of appetite

This treatment can affect your appetite. Do not worry if you do not eat much for a day or two. But if your appetite does not come back after a few days, tell your nurse or dietitian. They will give you advice. They may give you food or drink supplements.

Changes in the way the kidneys work

Methotrexate can affect how your kidneys work, but usually only when it is given in high doses. You will have blood tests before and during treatment to check this.

Before and after each treatment, your nurses will give you extra fluids through a drip. This is to protect your kidneys. It is also important to drink at least 2 litres (3½ pints) of fluids each day.

If you pass less urine (pee) than usual, tell your nurse.

Feeling tired

This treatment will make you feel very tired and you will need a lot of rest. You will get tired easily for some months after treatment too. Gentle exercise, like short walks, can give you more energy. The tiredness will gradually get better.

Headaches

This treatment may cause headaches. If this happens, tell your doctor or nurse. They can give you painkillers.

Soreness and redness of palms of hands and soles of feet

This is called palmar-plantar or hand-foot syndrome. It gets better when treatment ends. Your doctor or nurse can give you advice and give you creams to improve the symptoms. It can help to keep your hands and feet cool and to avoid tight-fitting socks, shoes and gloves. Tell your nurse about any changes in your hands or feet.

Skin changes

This treatment may affect your skin. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day. The treatment can cause a rash, which may be itchy. Always tell your doctor or nurse about any skin changes. They can give you advice and may give you creams or medicines to help. Any changes to your skin are usually temporary and improve when treatment finishes.

Hair loss

Your hair will get thinner or you may lose all the hair from your head. You may also lose your eyelashes, eyebrows or other body hair. Hair loss usually starts after your first or second treatment.

Your nurse can talk to you about ways to cope with hair loss. There are ways to cover up hair loss if you want to. It is important to cover your head to protect your scalp when you are out in the sun.

Hair loss is almost always temporary and your hair will usually grow back after treatment ends.

Effects on the liver

This treatment can affect how your liver works. This is usually mild and goes back to normal after treatment. You will have blood tests to check how well your liver is working. Your doctor or nurse may suggest you avoid alcohol and some medicines.

Eye problems

Your eyes may become watery and feel sore. Your doctor can prescribe eye drops to help with this. If your eyes get red and inflamed (conjunctivitis) tell your doctor. You may need antibiotic eye drops.

Cytarabine may also:

  • make your eyes more sensitive to light  
  • cause blurry vision
  • cause eye pain.

You will be given steroid eye drops to help prevent this. Always tell your doctor or nurse if you have pain or notice any change in your vision.

Less common side effects

Effects on the nervous system

High doses of methotrexate can affect the nervous system. You may feel drowsy or confused. If you notice these symptoms, tell your doctor or nurse straight away. It is important not to drive or operate machinery if you notice these effects. Rarely, methotrexate can cause seizures (fits). You doctor or nurse will explain more about this.

Effects on the lungs

This treatment can cause changes to the lungs. Tell your doctor if you develop:

  • a cough
  • wheezing
  • a fever (high temperature)
  • breathlessness.

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.

Raised levels of uric acid in the blood (tumour lysis syndrome)

This treatment may cause the cancer cells to break down quickly. This releases uric acid (a waste product) into the blood. The kidneys usually get rid of uric acid but may not be able cope with large amounts. Too much uric acid can cause swelling and pain in the joints (gout).

Your doctor may give you drugs to help prevent this. Drinking at least 2 litres (3½ pints) of fluid a day will also help. You will have regular blood tests to check the uric acid levels.

Other information

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:

  • pain, redness or swelling in a leg or arm
  • breathlessness
  • chest pain.

If you have any of these symptoms, contact a doctor straight away.

A blood clot is serious, but can be treated with drugs that thin the blood. Your doctor or nurse can give you more information.

Other medicines

Some medicines can affect how this treatment works or be harmful when you are having it. Always tell your cancer doctor about any drugs you are taking or planning to take, such as:

  • medicines you have been prescribed
  • medicines you buy in a shop or chemist
  • vitamins, herbal drugs and complementary therapies.

Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.

You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.

Contraception

Your doctor will advise you not to get pregnant or father a child while having this treatment. The drugs may harm the developing baby. It is important to use effective contraception during your treatment.

Breastfeeding

Women are advised not to breastfeed while having this treatment. This is because the drugs could be passed to the baby through breast milk.

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

Sex

If you have sex in the first few days after chemotherapy, you need to use a condom. This is to protect your partner in case there is any chemotherapy in semen or vaginal fluids.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses that you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.

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