MATRIX

MATRix is a combination of chemotherapy and a targeted therapy drug. It is used to treat primary CNS lymphoma. It may also 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, targeted therapies 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.

MATRix is named after the initials of the drugs it uses. The drugs are:

• methotrexate (M)
• Ara-C (A) – a brand of cytarabine
• thiotepa (T)
• rituximab (Rix)

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 protective layer (the blood–brain barrier) into the brain and spinal cord.

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 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.

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.

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.

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) for more detailed information.

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 sometimes called neutropenia.

An infection can be very serious when the number of white blood cells is low. It is important to get any infection treated as soon as possible. Contact the hospital straight away on the 24-hour contact number you have been given 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
• your temperature goes below 36°C (96.8°F).

Symptoms of an infection include:

• feeling shivery and shaking
• a sore throat
• a cough
• breathlessness
• diarrhoea
• needing to pass urine (pee) a lot, or discomfort when you pass urine.

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, until your cell count increases.

You may be given a drug called G-CSF. This encourages the body to make more white blood cells. You have it as a small injection under the skin.

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

If the number of platelets is low, you may bruise or bleed easily. You may have:

• nosebleeds
• bleeding gums
• heavy periods
• blood in your urine (pee) or stools (poo)
• tiny red or purple spots on the skin that may look like a rash.

Tell your doctor if you have any unexplained bruising or bleeding. You may need a drip to give you extra platelets. This is called a platelet transfusion.

This treatment can reduce the number of red blood cells in your blood. Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may have symptoms such as:

• pale skin
• lack of energy
• feeling breathless
• feeling dizzy and light-headed.

Tell your doctor or nurse if you have these symptoms.

If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

The nurses will give you anti-sickness drugs regularly to help prevent or control sickness during your treatment. If you feel sick or are sick (vomit), tell your nurse or doctor. They may change the anti-sickness drug to one that works better for you.

This treatment may cause a sore mouth and throat. You may also get mouth ulcers. This can make you more likely to get an infection in your mouth or throat. Use a soft toothbrush to clean your teeth or dentures in the morning, at night and after meals.

If your mouth or throat 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 and throat.

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.

This treatment may cause severe diarrhoea. Diarrhoea means passing more stools (poo) than is usual for you, or having watery or loose stools. If you have a stoma, it will be more active than usual.

Your hospital team may give you anti-diarrhoea drugs to take.

If you have diarrhoea or a mild increase in stoma activity:

• follow any advice from your cancer team about taking anti-diarrhoea drugs
• drink at least 2 litres (31/2 pints) of fluids each day
• avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods.

Tell your doctor or nurse straight away if:

• you have diarrhoea at night
• you have diarrhoea more than 4 times in a day
• you have a moderate or severe increase in stoma activity
• the anti-diarrhoea drugs do not work within 24 hours.

You may need to have extra fluids through a drip.

This treatment can cause inflammation in the gullet, stomach, or bowel.

You may get pain or discomfort in your tummy (abdomen), feel bloated or have indigestion.

Tell your doctor straight away if you have:

• severe tummy pain or a fever
• blood or mucus in your stools (poo)
• dark or tar-like stools

This treatment can cause constipation. Constipation means that you are not able to pass stools as often as you normally do. It can become difficult or painful.

If you have constipation, your doctor can give you drugs called laxatives to help.

This treatment can affect your appetite. Don't worry if you do not eat much for a day or 2. But if your appetite does not come back after a few days, or if you are losing weight, tell your nurse or dietitian. They can give you advice. They may give you food or drink supplements. Or they may suggest changes to your diet or eating habits to help.

Methotrexate can affect how your kidneys work, but usually only when you have it in high doses. Your doctor can tell you more about this. Your doctor will ask you about any other medicines or supplements you take, as some can affect how your kidneys clear methotrexate from your body.

You will have blood and urine tests before and during treatment to check how well your kidneys are working.

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 non-alcoholic fluid each day during treatment.

Tell your nurse or doctor if: 

• you are not able to drink as much as you have been asked to – for example, if you feel sick
• you are being sick or have diarrhoea 
• you are passing urine (peeing) less than usual.

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 has finished. Gentle exercise, like short walks, can give you more energy. The tiredness will slowly get better.

If you feel sleepy, do not drive or use machinery.

You may get pain in your muscles, joints or where your tumour is. If this happens, tell your doctor so they can give you painkillers. Tell them if the pain does not get better.

If you have painkillers you would like to use at home, check with your doctor, nurse or pharmacist whether they are suitable for you.

You may get sore and red palms of hands and soles of feet. The skin may also begin to peel. This is called palmar-plantar or hand-foot syndrome. It usually gets better after treatment ends.

Tell your doctor or nurse about any changes to your hands or feet. They can give you advice and prescribe creams to improve any symptoms you have. It can help to:

• keep your hands and feet cool
• moisturise your hands and feet regularly
• avoid tight-fitting socks, shoes and gloves.

This treatment may affect your skin. It may cause a rash, which might be itchy. It may cause redness or changes in skin colour. It may also make your skin more sensitive to sunlight.

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 

Your hair will get thinner. Or you may lose all the hair from your head. You may also lose your eyelashes and eyebrows, as well as 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. Your scalp may be sensitive. It is important to cover your head to protect your skin when you are out in the sun.

Hair loss is almost always temporary. Your hair will usually grow back after treatment finishes.

This treatment may affect how your liver works. This is usually mild. Liver problems may cause the skin or the whites of the eyes to become yellow.

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.

This treatment can raise your blood sugar levels. If you have a raised blood sugar level, you may:

• feeling thirsty
• needing to pass urine (pee) more often
• feeling tired.

Tell your doctor or nurse if you have these symptoms.

If you have diabetes, your blood sugar levels may be higher than usual. Your doctor will talk to you about how to manage this. You may need to change your insulin or tablet dose.

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, tell your doctor. This is called conjunctivitis. You may need antibiotic eye drops.

Always tell your doctor or nurse if you have pain or notice any change in your vision. 

Cytarabine and methotrexate 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. 

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

• throbbing pain, redness or swelling in a leg or arm
• suddenly feeling breathless or coughing
• sharp chest pain, which may be worse when you cough or take a deep breath.

If you have any of these symptoms, contact the hospital straight away on the 24-hour contact number you have been given. If you cannot get through to your doctor, call the NHS urgent advice number on 111.

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

You can help reduce the risk of developing a blood clot by:

• staying active during treatment
• drinking plenty of fluids, especially water.

You may be given anticoagulants to help prevent a clot.

If you have had hepatitis B (a liver infection) in the past, rituximab can make it active again. Your doctor or nurse will talk to you about this and test you for hepatitis B. If you have active hepatitis B, you will not have treatment with rituximab.

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.

Vaccinations can reduce your risk of getting certain infections. Your doctor or nurse may talk to you about having vaccinations.

Doctors usually recommend that people with cancer have a flu vaccination and a coronavirus (covid) vaccination. These are both inactivated vaccinations that can help reduce the risk of infection. People with weak immune systems can have these, as they are not live vaccinations. 

If your immune system is weak, you need to avoid live vaccinations. This is because they can make you unwell. Live vaccines contain a very weak version of the illness they are vaccinating you against. Your cancer doctor or GP can tell you more about live and inactivated vaccinations.

Your doctor will advise you not to get pregnant or make someone pregnant while having this treatment. The drugs may harm a developing baby. It is important to use contraception during your treatment and for a while after treatment finishes. Your doctor, nurse or pharmacist can tell you more about this.

You are advised not to breastfeed while having this treatment, or for some time after treatment finishes. This is because the drugs could be passed to the baby through breast milk.

Your doctor or nurse can give you more information.

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.

If you have sex in the first few days after this treatment, you should use barrier protection such as a condom or dental dam. This will protect your partner if any of the drug is in your semen or vaginal fluids.

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses 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.