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.

This information is correct at time of publishing. But sometimes the types of cancer this treatment is used for, or treatment side effects, may change between revision dates.

You can talk to your cancer team if you want more detailed information about this treatment. Or visit the electronic Medicines Compendium (eMC) website, which has patient information leaflets (PIL) for individual drugs.

We explain the most common side effects of this treatment here. We also include some that are less common.

You may get some of the side effects we mention, but you are unlikely to get all of them. And you may have some side effects, including rarer ones, that we have not listed here. 

Always tell your doctor, nurse or pharmacist about any side effects you have. They can give you: 

• drugs to help control some side effects
• advice about managing side effects. 

It is important to take any drugs exactly as explained. This means they will be more likely to work for you. 

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

Your doctor, nurse or pharmacist will give you 24-hour contact numbers for the hospital. If you feel unwell or need advice, you can call at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If your white blood cell count is low, you may be more likely to get an infection. A low white blood cell count is 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. If you have any of the following symptoms, contact the hospital straight away on the 24-hour number:

• a temperature above 37.5°C 
• a temperature below 36°C 
• you feel unwell, even with a normal temperature
• you have symptoms of an infection.

Symptoms of an infection include:

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

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

Your white blood cell count 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, brown or purple spots that may look like a rash – these spots can be harder to see if you have black or brown skin. 

If you have any unexplained bruising or bleeding, contact the hospital straight away on the 24-hour number. 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 feel:

• very low in energy
• breathless 
• dizzy and light-headed. 

If you have these symptoms, contact the hospital straight away on the 24-hour number. You may need treatment for anaemia. 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. This will help prevent or control sickness during your treatment in hospital. If you feel sick or are sick (vomit), tell your nurse or doctor straight away. They can change the anti-sickness treatment. Or they might change the way you have it to something 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.

Some foods may taste different or have no taste. Try different foods to find out what tastes best to you. You may also get a bitter or metallic taste in your mouth. Your doctor, nurse or pharmacist can give you advice. It might help to try:

• sucking sugar-free sour or boiled sweets
• eating cold foods
• eating sharp-tasting fresh fruit.

Taste changes usually get better after treatment ends. We have more information about coping with changes to taste.

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 1 or 2 days. But if your appetite does not come back after a few days, or if you are losing weight, tell your doctor, nurse or pharmacist. 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 can make you feel very tired and you will need a lot of rest. You may get tired easily for some months after treatment ends. Gentle exercise, like short walks, can help you feel less tired. 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.

This treatment can affect the palms of your hands and the soles of your feet. This is called palmar-plantar or hand-foot syndrome. 

If you have white skin these areas may become red. If you have black or brown skin, these areas might get darker. 

The skin on the palms of your hands and the soles of your feet may:

• be sore
• be painful, tingle, or swell
• peel, crack or blister. 

If you have any of these symptoms, contact the hospital straight away on the 24-hour number. They can give you advice. This is especially important if you have any broken skin or if walking is difficult. They can prescribe creams and painkillers to help.

You can care for your hands and feet by: 

• keeping your hands and feet cool by washing in cool water
• gently moisturising your hands and feet regularly
• wearing gloves to protect your hands and nails when working in the house or garden
• wearing loose cotton socks and avoiding tight-fitting 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.

If you want to cover up hair loss, there are different ways you can do this. Your nurse will give you information about coping with hair loss. 

Remember to protect your skin from the sun. Use suncream with a sun protection factor (SPF) of at least 30 on your scalp. Or cover up with a hat or scarf.

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

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 and increase the risk of diabetes. 

Signs of raised blood sugar include:

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

Tell your doctor or nurse if you have these symptoms. They can do tests to check your blood sugar level and give you advice.

If you already have diabetes, your blood sugars may be higher than usual. You may need to check them more often, or make changes to your diabetic treatment. Your diabetic doctor or nurse will talk to you about how to manage this.

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. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

• throbbing pain or swelling in a leg or arm
• reddening of the skin in the area – if you have black or brown skin, this can be harder to notice, but the skin might become darker
• suddenly feeling breathless or coughing.

Always call 999 if you have:

• chest pain
• difficulty breathing.

A blood clot is serious, but it can be treated with drugs called anticoagulants. These thin the blood. Your doctor, nurse or pharmacist can give you more information about preventing and treating blood clots.

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 while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

• medicines you have been prescribed
• medicines you buy in a shop, pharmacy or online
• vitamins or supplements 
• herbal drugs and complementary or homeopathic therapies
• recreational drugs – for example, cannabis.

Doctors usually recommend that people with cancer have vaccinations for flu and for coronavirus (covid). These help reduce your risk of serious illness from these infections. Most people can have these vaccines, including people with weak immune systems.

If your immune system is weak, you should not have live vaccinations. Live vaccines can make you unwell because they contain a very weak version of the illness they will protect you against. Live vaccines include Zostavax^®, which is a shingles vaccine, and the yellow fever vaccine.

It is important to ask your doctor, nurse or pharmacist for advice about having vaccinations. They can explain what vaccines are right for you and when it is best to have them.

Your doctor, nurse or pharmacist will advise you not to get pregnant or make someone pregnant while having this treatment and for some time afterwards. The drugs may harm a developing baby. It is important to use contraception to prevent pregnancy. Follow their advice about:

• what types of contraception to use 
• how long after treatment you should continue to use contraception. 

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

Your doctor, nurse or pharmacist 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.

It is possible that small amounts of chemotherapy may be passed on through vaginal fluids or semen. If you have sex in the first few days after treatment, your cancer team will usually advise using condoms or a dental dam to protect your partner.

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

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.