Read about chemotherapy for breast cancer, including what it is, when it might be given, benefits and possible side effects.

1. What is chemotherapy?

Chemotherapy is a treatment that destroys cancer cells using anti-cancer drugs. It works by interfering with the cancer cells’ ability to divide and grow.

Different chemotherapy drugs work in different ways. This is why a combination of drugs is often used.

Chemotherapy affects cells throughout the body and can cause side effects.


2. When is chemotherapy given?

Primary breast cancer

After surgery

Chemotherapy may be used after surgery for to reduce the risk of cancer returning or spreading. This is called adjuvant chemotherapy. You may be given chemotherapy in combination with other treatments.

Before surgery

Chemotherapy may be used before surgery to slow the growth of rapidly growing breast cancer. Or it might be given to shrink a larger breast cancer before surgery (this may mean breast-conserving surgery is an option, rather than a ).

Chemotherapy given before surgery is called primary or neo-adjuvant chemotherapy.

People with certain types of breast cancer, such as or whose breast cancer is HER2 positive or people who have triple negative breast cancer may be more likely to have chemotherapy before surgery.

Secondary breast cancer

Chemotherapy can also be used to treat secondary breast cancer. Secondary breast cancer occurs when breast cancer cells have spread to another part of the body.

Secondary breast cancer, also called metastatic breast cancer, can be treated but cannot be cured.

Chemotherapy can be used to control or slow the growth of secondary breast cancer. It can also help relieve some symptoms.

Different chemotherapy drugs are used to treat secondary breast cancer. You may be given them alone, or in combination with other treatments.


3. Chemotherapy drugs

4. What are the benefits of chemotherapy?

Find out more about the benefits of chemotherapy for treating primary breast cancer.

The benefits of chemotherapy for treating secondary breast cancer will depend on where the secondary breast cancer is in the body and any chemotherapy you’ve had before.

5. Before starting chemotherapy

Before starting your treatment, most hospitals will arrange a chemotherapy information session. At this appointment, a nurse will discuss how and when your chemotherapy will be given and how side effects can be managed.

You may have blood tests and some people will have an ECG (electrocardiogram), a simple test that checks your heart rhythm.

You may also have an echo (echocardiogram) - an of your heart. Your height and weight will be measured. This is to work out the correct dose of chemotherapy for you.

You will be given contact numbers so you know who to phone if you have any questions or concerns.

You will be asked to sign a consent form before you start chemotherapy. The benefits and risks of the treatment should be explained before you sign.

Shortly before each cycle of treatment, and sometimes in between, you’ll have a blood test. This is because if the number of blood in the body is too low, treatment may need to be delayed.

You’ll usually be given anti-sickness drugs before each chemotherapy treatment.

The drugs you’re given will depend on the type of chemotherapy you’re having, but will often include a steroid drug called dexamethasone, as well as other anti-sickness medication.

6. How is chemotherapy given?

Chemotherapy can be given in several ways. For breast cancer, the drugs are most commonly given:

  • Into a vein (intravenously)
  • By mouth as tablets or capsules (orally)
  • Electrochemotherapy

7. Where is chemotherapy given?

Unless you’re having chemotherapy as tablets, you’ll normally be given your treatment at hospital as an outpatient or day case. This means you’ll be able to go home on the same day.

You may be at the hospital for a short time only.

But because of tests, waiting times and how long it takes to prepare and give the chemotherapy drugs, some people are there for most of the day.

You may be asked to have blood tests a few days before you have your chemotherapy.

You might find it helpful to take things to help pass the time, as well as snacks and drinks. You may be able to take someone to go with you to keep you company. Talk to your chemotherapy nurse to find out if this is possible.

In some areas, chemotherapy may be given in a mobile treatment centre or in your home.

With some types of chemotherapy, you may be given your first treatment as an inpatient and may need to stay in hospital overnight.

8. How long will I have chemotherapy for?

Chemotherapy is commonly given as a series of treatments, with a break between each treatment to give your body time to recover from any short-term side effects. The treatment and period of time before the next one starts is called a cycle.

You may have treatment weekly or every two or three weeks.

You may have one drug or a combination of two or three drugs. The exact type and dose of chemotherapy will be tailored to your individual situation.

The drugs used, the dose, how often they’re given and the number of cycles may be called your chemotherapy regime or regimen.

The length of time that you have chemotherapy will depend on your individual situation. Your treatment team will discuss this with you.

9. Side effects of chemotherapy

Like any treatment, chemotherapy can cause side effects. Everyone reacts differently to drugs and some people have more side effects than others.

Find out about the side effects of chemotherapy.

10. Other important information

Complementary therapies

Many people find that complementary therapies help them cope with the side effects of chemotherapy, even though there may not be the evidence to support this.

Check with your treatment team or GP before having any complementary therapies, and mention your breast cancer and treatment to any therapist you see. Your GP or treatment team may advise avoiding some therapies (particularly herbal remedies) if there’s a chance they could affect how your breast cancer treatment works.

Some therapies are available in NHS hospitals so ask your treatment team what’s available to you.

Diet and supplements

You may be able to eat normally throughout chemotherapy or your eating habits may change because of side effects.

It’s important to eat and drink what you feel able to, maintaining a healthy, well-balanced diet wherever possible.

Tell your treatment team about any supplements or remedies you’re taking or considering taking, including:

  • Vitamin and mineral supplements
  • Herbal remedies
  • Any treatments that are bought over the counter 

The evidence is not clear whether supplements like vitamins, particularly high-dose antioxidants (including vitamins A, C and E, co-enzyme Q10 and selenium), are harmful or helpful during chemotherapy. 

Because of this uncertainty, many specialists recommend people don’t take high-dose antioxidant supplements during chemotherapy.

Sex, contraception and pregnancy

You can still have sex during treatment. It’s thought that chemotherapy drugs can’t pass into vaginal fluids or semen. But this can’t be completely ruled out as chemotherapy drugs can pass into the blood and some other body fluids.

Most treatment teams will advise using barrier methods of contraception, such as condoms during treatment, and for a few days after chemotherapy is given. 

If you haven’t been through the menopause, it’s important to use contraception because chemotherapy drugs can harm a developing baby in the first three months of pregnancy.

It’s still possible to become pregnant even if your periods become irregular or stop completely.

Your specialist will usually recommend barrier methods of contraception, such as condoms.

The contraceptive pill is not usually recommended because it contains hormones. Emergency contraception like the morning after pill can still be used.

An intrauterine device (IUD or coil) can be used, as long as it’s not the type that releases hormones.

If you have a coil in place that does release , like the Mirena or Jaydess, when you’re diagnosed, you may be advised to have this removed.

Find out more about how breast cancer and its treatment can affect sex and intimacy and read our tips on how to manage these changes.

Travel and vaccinations

If you’re planning a holiday or need to travel overseas, check with your treatment team first. 

You shouldn’t have any live vaccines while you’re having chemotherapy. Live vaccines include mumps, measles, rubella (German measles), polio, BCG (tuberculosis), shingles and yellow fever. 

Live vaccines contain a small amount of live virus or bacteria. If you have a weakened immune system, which you may do during chemotherapy, they could be harmful.

It’s safe to have these vaccinations six months after your treatment finishes. Talk to your GP or treatment team before having any vaccinations.

If anyone you have close contact with needs to have a live vaccine, speak to your treatment team or GP. They can advise what precautions you may need to take depending on the vaccination.

Flu vaccination

Anyone at risk of a weakened immune system, and therefore more prone to infection, should have the flu vaccine. This includes people due to have, or already having, chemotherapy.

The flu vaccine is not a live vaccine so doesn’t contain any active viruses. Talk to your chemotherapy team or breast care nurse about the best time to have your flu jab.

Coronavirus (Covid-19) vaccination

People having chemotherapy are advised to speak to their treatment team before having a coronavirus (Covid-19) vaccination.

11. Further support

It’s common to feel anxious or frightened about having chemo. Not knowing what to expect can be very distressing.

Many people worry about the side effects they might get. But most side effects can be controlled. You should be told what side effects to report, as well as details of who to contact, day or night, if you have any concerns or are unwell.

Your chemotherapy team and breast care nurse can help with any questions you have.

On our online forum, you can find people going through treatment at the same time as you on the chemotherapy monthly threads.

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Last reviewed in July 2021. The next planned review begins in July 2023.

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