Health A to Z
Breast cancer is the most common type of cancer in the UK. Most women diagnosed with breast cancer are over 50, but younger women can also get breast cancer.
About one in eight women are diagnosed with breast cancer during their lifetime. There's a good chance of recovery if it's detected in its early stages.
For this reason, it's vital that women check their breasts regularly for any changes and always get any changes examined by their GP.
In rare cases, men can also be diagnosed with breast cancer. Read about breast cancer in men.
This topic covers:
Breast cancer can have a number of symptoms, but the first noticeable symptom is usually a lump or area of thickened breast tissue.
Most breast lumps aren't cancerous, but it's always best to have them checked by your doctor.
You should also see your GP if you notice any of the following:
Breast pain isn't usually a symptom of breast cancer.
Read more about the symptoms of breast cancer.
The exact causes of breast cancer aren't fully understood. However, there are certain factors known to increase the risk of breast cancer.
Read more about the causes of breast cancer.
After examining your breasts, your GP may refer you to a specialist breast cancer clinic for further tests. This might include breast screening (mammography) or a biopsy.
Read about how breast cancer is diagnosed.
There are several different types of breast cancer, which can develop in different parts of the breast.
Breast cancer is often divided into:
Other less common types of breast cancer include:
It's possible for breast cancer to spread to other parts of the body, usually through the bloodstream or the axillary lymph nodes. These are small lymphatic glands that filter bacteria and cells from the mammary gland.
If this happens, it's known as secondary, or metastatic, breast cancer.
Mammographic screening, where X-ray images of the breast are taken, is the most commonly available method of detecting an early breast lesion.
However, you should be aware that a mammogram might fail to detect some breast cancers.
It might also increase your chances of having extra tests and interventions, including surgery, even if you're not affected by breast cancer.
Women with a higher-than-average risk of developing breast cancer may be offered screening and genetic testing for the condition.
As the risk of breast cancer increases with age, all women who are 50 to 70 years old are invited for breast cancer screening every three years.
Women over the age of 70 are also entitled to screening and can arrange an appointment through their GP or local screening unit.
The NHS is in the process of extending the programme as a trial, offering screening to some women aged 47 to 73.
Read about breast screening.
If cancer is detected at an early stage, it can be treated before it spreads to nearby parts of the body.
Breast cancer is treated using a combination of:
Surgery is usually the first type of treatment you'll have, followed by chemotherapy or radiotherapy or, in some cases, hormone or biological treatments.
The type of surgery and the treatment you have afterwards will depend on the type of breast cancer you have. Your doctor will discuss the best treatment plan with you.
In a small proportion of women, breast cancer is discovered after it's spread to other parts of the body (metastatic breast cancer).
Secondary cancer, also called advanced or metastatic cancer, isn't curable, so the aim of treatment is to achieve remission (symptom relief).
Read about treating breast cancer.
Being diagnosed with breast cancer can affect daily life in many ways, depending on what stage it's at and the treatment you're having.
How women cope with their diagnosis and treatment varies from person to person. You can be reassured that there are several forms of support available, if you need it.
Read about living with breast cancer.
As the causes of breast cancer aren't fully understood, at the moment it's not possible to know if it can be prevented.
If you're at increased risk of developing the condition, some treatments are available to reduce the risk.
Studies have looked at the link between breast cancer and diet. Although there are no definite conclusions, there are benefits for women who:
It's been suggested that regular exercise can reduce your risk of breast cancer by as much as a third. Regular exercise and a healthy lifestyle can also improve the outlook for people affected by breast cancer.
If you've been through the menopause, it's particularly important that you're not overweight or obese.
This is because being overweight or obese causes more oestrogen to be produced, which can increase the risk of breast cancer.
Read about preventing breast cancer.
The first symptom of breast cancer most women notice is a lump or an area of thickened tissue in their breast.
Most breast lumps (90%) aren't cancerous, but it's always best to have them checked by your doctor.
You should see your GP if you notice any of the following:
Breast pain isn't usually a symptom of breast cancer.
It's important to be breast aware so you can pick up any changes as soon as possible.
Get to know what is normal for you – for instance, your breasts may look or feel different at different times of your life. This will make it much easier to spot potential problems.
The causes of breast cancer aren't fully understood, making it difficult to say why one woman may develop breast cancer and another may not.
However, there are risk factors known to affect your likelihood of developing breast cancer. Some of these you can't do anything about, but there are some you can change.
The risk of developing breast cancer increases with age. The condition is most common among women over 50 who have been through the menopause. About 8 out of 10 cases of breast cancer occur in women over 50.
All women who are 50 to 70 years of age should be screened for breast cancer every three years as part of the NHS Breast Screening Programme.
Women over the age of 70 are still eligible to be screened and can arrange this through their GP or local screening unit.
Read more about breast screening.
If you have close relatives who have had breast cancer or ovarian cancer, you may have a higher risk of developing breast cancer.
However, because breast cancer is the most common cancer in women, it's possible for it to occur in more than one family member by chance.
Most cases of breast cancer don't run in families, but particular genes known as BRCA1 and BRCA2 can increase your risk of developing both breast and ovarian cancer. It's possible for these genes to be passed on from a parent to their child.
Other newly detected genes, such as TP53 and CHEK 2, are also associated with an increased risk of breast cancer.
If you have, for example, two or more close relatives from the same side of your family – such as your mother, sister or daughter – who have had breast cancer under the age of 50, you may be eligible for surveillance for breast cancer, or genetic screening to look for the genes that make developing breast cancer more likely.
If you're worried about your family history of breast cancer, discuss it with your GP.
Read about predictive genetic tests for cancer risk genes.
If you've previously had breast cancer or early non-invasive cancer cell changes in breast ducts, you have a higher risk of developing it again, either in your other breast or in the same breast.
A benign breast lump doesn't mean you have breast cancer, but certain types of lump may slightly increase your risk of developing it.
Certain benign changes in your breast tissue, such as cells growing abnormally in ducts (atypical ductal hyperplasia), or abnormal cells inside your breast lobes (lobular carcinoma in situ), can make getting breast cancer more likely.
Your breasts are made up of thousands of tiny glands (lobules) that produce milk. This glandular tissue contains a higher concentration of breast cells than other breast tissue, making it denser.
Women with dense breast tissue may have a higher risk of developing breast cancer as there are more cells that can become cancerous.
Dense breast tissue can also make a breast scan (mammogram) difficult to read, as any lumps or areas of abnormal tissue are harder to spot.
Younger women tend to have denser breasts. As you get older, the amount of glandular tissue in your breasts decreases and is replaced by fat, so your breasts become less dense.
The female hormone oestrogen can sometimes stimulate breast cancer cells and cause them to grow.
The ovaries, where your eggs are stored, begin to produce oestrogen when you start puberty to regulate your periods.
Your risk of developing breast cancer may rise slightly with the amount of oestrogen your body is exposed to.
For example, if you started your periods at a young age and experienced the menopause at a late age, you'll have been exposed to oestrogen over a longer period of time.
In the same way, not having children or having children later in life may slightly increase your risk of developing breast cancer because your exposure to oestrogen is not interrupted by pregnancy.
If you've experienced the menopause and are overweight or obese, you may be more at risk of developing breast cancer.
This is thought to be linked to the amount of oestrogen in your body, as being overweight or obese after the menopause causes more oestrogen to be produced.
Your risk of developing breast cancer can increase with the amount of alcohol you drink.
Research shows that for every 200 women who regularly have two alcoholic drinks a day, there are three more women with breast cancer compared with women who don't drink at all.
If you had radiotherapy to your chest area for Hodgkin lymphoma when you were a child, you should have already received a letter from the Department of Health inviting you for a consultation with a specialist to discuss your increased risk of developing breast cancer.
See your GP if you weren't contacted or if you didn't attend a consultation. You're usually entitled to having your breast checked with an MRI scan.
If you currently need radiotherapy for Hodgkin lymphoma, your specialist should discuss the risk of breast cancer before your treatment begins.
Hormone replacement therapy (HRT) is associated with an increased risk of developing breast cancer.
Both combined HRT and oestrogen-only HRT can increase your risk of developing breast cancer, although the risk is slightly higher if you take combined HRT.
It's estimated there will be an extra 19 cases of breast cancer for every 1,000 women taking combined HRT for 10 years. The risk continues to increase slightly the longer you take HRT, but returns to normal once you stop taking it.
The prolonged use of HRT is not usually recommended, especially if you find it possible to cope with symptoms of the menopause.
Research has shown that women who use the contraceptive pill have a slightly increased risk of developing breast cancer.
However, the risk starts to decrease once you stop taking the pill, and your risk of breast cancer is back to normal 10 years after stopping.
If you have suspected breast cancer, either because of your symptoms or because your mammogram has shown an abnormality, you'll be referred to a specialist breast cancer clinic for further tests.
If you have symptoms and have been referred to a specialist breast unit by your GP, you'll probably be invited to have a mammogram, which is an X-ray of your breasts. You may also need an ultrasound scan.
If your cancer was detected through the NHS Breast Screening Programme, you may need another mammogram or ultrasound scan.
Your doctor may suggest that you only have a breast ultrasound scan if you're under the age of 35. This is because younger women have denser breasts, which means a mammogram isn't as effective as ultrasound in detecting cancer.
Ultrasound uses high-frequency sound waves to produce an image of the inside of your breasts, showing any lumps or abnormalities.
Your breast specialist may also suggest a breast ultrasound if they need to know whether a lump in your breast is solid or contains liquid.
Read more about breast screening.
A biopsy is where a sample of tissue cells is taken from your breast and tested to see if it's cancerous.
You may also need a scan and a needle test on lymph nodes in your armpit (axilla) to see whether these are also affected.
Biopsies can be taken in different ways, and the type you have will depend on what your doctor knows about your condition.
Different methods of carrying out a biopsy are discussed below.
Needle aspiration may be used to test a sample of your breast cells for cancer or drain a small fluid-filled lump (benign cyst).
Your doctor will use a small needle to extract a sample of cells, without removing any tissue.
Needle biopsy is the most common type of biopsy. A sample of tissue is taken from a lump in your breast using a large needle.
You'll have a local anaesthetic, which means you'll be awake during the procedure, but your breast will be numb.
Your doctor may suggest that you have a guided needle biopsy, usually guided by ultrasound or X-ray, but sometimes MRI, to obtain a more precise and reliable diagnosis of cancer.
This also can distinguish it from any non-invasive change, particularly ductal carcinoma in situ (DCIS).
Vacuum-assisted biopsy, also known as mammotome biopsy, is another type of biopsy.
During the procedure, a needle is attached to a gentle suction tube, which helps to obtain the sample and clear any bleeding from the area.
If a diagnosis of breast cancer is confirmed, more tests will be needed to determine the stage and grade of the cancer, and work out the best method of treatment.
Computerised tomography (CT) scans or chest X-ray and liver ultrasound scans may be needed to check whether the cancer has spread.
An MRI scan of the breast may be needed to clarify the results or assess the extent of the condition within the breast.
If your doctor thinks the cancer could have spread to your bones, you may need a bone scan.
Before having a bone scan, a substance containing a small amount of radiation known as an isotope will be injected into a vein in your arm.
This will be absorbed into your bone if it's been affected by cancer. The affected areas of bone will show up as highlighted areas on the bone scan, which is carried out using a special camera.
You'll also need tests that show whether the cancer will respond to specific types of treatment.
The results of these tests can give your doctors a more complete picture of the type of cancer you have and how best to treat it.
The types of test you could be offered are discussed below.
In some cases, breast cancer cells can be stimulated to grow by hormones that occur naturally in your body, such as oestrogen and progesterone.
If this is the case, the cancer may be treated by stopping the effects of the hormones or by lowering the level of these hormones in your body. This is known as hormone therapy.
During a hormone receptor test, a sample of cancer cells will be taken from your breast and tested to see if they respond to either oestrogen or progesterone.
If the hormone is able to attach to the cancer cells using a hormone receptor, they're known as hormone receptor positive.
While hormones can encourage the growth of some types of breast cancer, other types are stimulated by a protein called human epidermal growth factor receptor 2 (HER2).
These types of cancer can be diagnosed using a HER2 test, and are treated with medication to block the effects of HER2. This is known as biological or targeted therapy.
When your breast cancer is diagnosed, the doctors will give it a stage. The stage describes the size of the cancer and how far it has spread, and helps to predict the outlook.
Ductal carcinoma in situ (DCIS) is sometimes described as stage 0. Other stages of breast cancer describe invasive breast cancer:
This is a simplified guide. Each stage is divided into further categories: A, B and C. If you're not sure what stage you have, ask your doctor.
The TNM staging system may also be used to describe breast cancer, as it can provide accurate information about the diagnosis:
The grade describes the appearance of the cancer cells.
Surgery is usually the first type of treatment for breast cancer. The type of surgery you undergo will depend on the type of breast cancer you have.
Surgery is usually followed by chemotherapy or radiotherapy or, in some cases, hormone or biological treatments. Again, the treatment you'll have will depend on the type of breast cancer.
Your doctor will discuss the most suitable treatment plan with you. Chemotherapy or hormone therapy will sometimes be the first treatment.
Most breast cancers are discovered in the condition's early stages. However, a small proportion of women discover that they have breast cancer after it's spread to other parts of the body (metastasis).
If this is the case, the type of treatment you have may be different. Secondary cancer, also called "advanced" or "metastatic" cancer, isn't curable.
Treatment aims to achieve remission, where the cancer shrinks or disappears, and you feel normal and able to enjoy life to the full.
There are two main types of breast cancer surgery:
In many cases, a mastectomy can be followed by reconstructive surgery to try to recreate a bulge to replace the breast that was removed.
Studies have shown that breast-conserving surgery followed by radiotherapy is as successful as total mastectomy at treating early-stage breast cancer.
Breast-conserving surgery ranges from a lumpectomy or wide local excision, where just the tumour and a little surrounding breast tissue is removed, to a partial mastectomy or quadrantectomy, where up to a quarter of the breast is removed.
If you have breast-conserving surgery, the amount of breast tissue you have removed will depend on:
Your surgeon will always remove an area of healthy breast tissue around the cancer, which will be tested for traces of cancer.
If there's no cancer present in the healthy tissue, there's less chance that the cancer will return.
If cancer cells are found in the surrounding tissue, more tissue may need to be removed from your breast.
After having breast-conserving surgery, you'll usually be offered radiotherapy to destroy any remaining cancer cells.
A mastectomy is the removal of all the breast tissue, including the nipple.
If there are no obvious signs that the cancer has spread to your lymph nodes, you may have a mastectomy, where your breast is removed, along with a sentinel lymph node biopsy.
If the cancer has spread to your lymph nodes, you'll probably need more extensive removal (clearance) of lymph nodes from the axilla under your arm.
Breast reconstruction is surgery to make a new breast shape that looks like your other breast as much as possible.
Reconstruction can be carried out at the same time as a mastectomy (immediate reconstruction), or it can be carried out later (delayed reconstruction).
It can be done either by inserting a breast implant or by using tissue from another part of your body to create a new breast.
To find out if the cancer has spread, a procedure called a sentinel lymph node biopsy may be carried out.
The sentinel lymph nodes are the first lymph nodes that the cancer cells reach if they spread. They're part of the lymph nodes under the arm (axillary lymph nodes).
The position of the sentinel lymph nodes varies, so they're identified using a combination of a radioisotope and a blue dye.
The sentinel lymph nodes are examined in the laboratory to see if there are any cancer cells present. This provides a good indicator of whether the cancer has spread.
If there are cancer cells in the sentinel nodes, you may need further surgery to remove more lymph nodes from under the arm.
Radiotherapy uses controlled doses of radiation to kill cancer cells. It's usually given after surgery and chemotherapy to kill any remaining cancer cells.
If you need radiotherapy, your treatment will begin about a month after your surgery or chemotherapy to give your body a chance to recover.
You'll probably have radiotherapy sessions three to five days a week, for three to six weeks. Each session will only last a few minutes.
The type of radiotherapy you have will depend on your cancer and the type of surgery you have. Some women may not need to have radiotherapy at all.
The types available are:
The side effects of radiotherapy include:
Chemotherapy involves using anti-cancer (cytotoxic) medication to kill the cancer cells.
It's usually used after surgery to destroy any cancer cells that haven't been removed. This is called adjuvant chemotherapy.
In some cases, you may have chemotherapy before surgery, which is often used to shrink a large tumour. This is called neo-adjuvant chemotherapy.
Several different medications are used for chemotherapy, and three are often given at once.
The choice of medication and the combination will depend on the type of breast cancer you have and how much it's spread.
Chemotherapy is usually given as an outpatient treatment, which means you won't have to stay in hospital overnight. The medications are usually given through a drip straight into the blood through a vein.
In some cases, you may be given tablets that you can take at home. You may have chemotherapy sessions once every two to three weeks, over a period of four to eight months, to give your body a rest in between treatments.
The main side effects of chemotherapy are caused by their influence on normal, healthy cells, such as immune cells.
Side effects include:
Many side effects can be prevented or controlled with medicines that your doctor can prescribe.
Chemotherapy medication can also stop the production of oestrogen in your body, which is known to encourage the growth of some breast cancers.
If you haven't experienced the menopause, your periods may stop while you're undergoing chemotherapy treatment.
After you've finished the course of chemotherapy, your ovaries should start producing oestrogen again.
However, this doesn't always happen and you may enter an early menopause. This is more likely in women over 40, as they're closer to menopausal age.
Your doctor will discuss the impact any treatment will have on your fertility with you.
If your breast cancer has spread beyond the breast and lymph nodes to other parts of your body, chemotherapy won't cure the cancer, but it may shrink the tumour, relieve your symptoms and help lengthen your life.
Some breast cancers are stimulated to grow by the hormones oestrogen or progesterone, which are found naturally in your body.
These types of cancer are known as hormone receptor-positive cancers. Hormone therapy works by lowering the levels of hormones in your body or by stopping their effects.
The type of hormone therapy you'll have will depend on the stage and grade of your cancer, which hormone it's sensitive to, your age, whether you've experienced the menopause, and what other type of treatment you're having.
You'll probably have hormone therapy after surgery and chemotherapy, but it's sometimes given before surgery to shrink a tumour, making it easier to remove.
Hormone therapy may be used as the only treatment for breast cancer if your general health prevents you having surgery, chemotherapy or radiotherapy.
In most cases, you'll need to take hormone therapy for up to five years after having surgery. If your breast cancer isn't sensitive to hormones, hormone therapy will have no effect.
Tamoxifen stops oestrogen from binding to oestrogen-receptor-positive cancer cells. It's taken every day as a tablet or liquid.
It can cause several side effects, including:
If you've experienced the menopause, you may be offered an aromatase inhibitor.
This type of medication works by blocking aromatase, a substance that helps produce oestrogen in the body after the menopause. Before the menopause, oestrogen is made by the ovaries.
Three aromatase inhibitors may be offered. These are anastrozole, exemestane and letrozole. These are taken as a tablet once a day.
Side effects include:
In women who haven't experienced the menopause, oestrogen is produced by the ovaries. Ovarian ablation or suppression stops the ovaries working and producing oestrogen.
Ablation can be carried out using surgery or radiotherapy. It stops the ovaries working permanently and means you'll experience the menopause early.
Ovarian suppression involves using a medication called goserelin, which is a luteinising hormone-releasing hormone agonist (LHRHa).
Your periods will stop while you're taking it, although they should start again once your treatment is complete.
If you're approaching the menopause (around the age of 50), your periods may not start again after you stop taking goserelin.
Goserelin is taken as an injection once a month and can cause menopausal side effects, including:
Some breast cancers are stimulated to grow by a protein called human epidermal growth factor receptor 2 (HER2). These cancers are called HER2-positive.
Biological therapy works by stopping the effects of HER2 and helping your immune system to fight off cancer cells.
If you have high levels of the HER2 protein and are able to have biological therapy, you'll probably be prescribed a medicine called trastuzumab.
Trastuzumab, also known by the brand name Herceptin, is usually used after chemotherapy.
Trastuzumab is a type of biological therapy known as a monoclonal antibody.
Antibodies occur naturally in your body and are made by your immune system to destroy harmful cells, such as viruses and bacteria.
The trastuzumab antibody targets and destroys cancer cells that are HER2-positive.
Trastuzumab is usually given intravenously, through a drip. It's also sometimes available as an injection under the skin (a subcutaneous injection).
You'll have the treatment in hospital. Each treatment session takes up to one hour, and the number of sessions you need will depend on whether you have early or more advanced breast cancer.
On average, you'll need a session once every three weeks for early breast cancer, and weekly sessions if your cancer is more advanced.
Trastuzumab can cause side effects, including heart problems. This means that it's not suitable if you have a heart problem, such as angina, uncontrolled high blood pressure (hypertension), or heart valve disease.
If you need to take trastuzumab, you'll have regular tests on your heart to make sure it's not causing any problems.
Other side effects of trastuzumab may include:
A great deal of progress has been made in breast cancer treatment, and more women now live longer and have fewer side effects from treatment.
These advances were discovered in clinical trials, where new treatments and treatment combinations are compared with standard ones.
All cancer trials in the UK are carefully overseen to ensure they're worthwhile and safely conducted. In fact, participants in clinical trials can do better overall than those in routine care.
If you're asked to take part in a trial, you'll be given an information sheet and, if you want to take part, you'll be asked to sign a consent form. You can refuse or withdraw from a clinical trial without it affecting your care.
Dealing with cancer can be a huge challenge for both patients and their families. It can cause emotional and practical difficulties.
Many women have to cope with the removal of part or all of a breast, which can be very upsetting.
It often helps to talk about your feelings or other difficulties with a trained counsellor or therapist. You can ask for this kind of help at any stage of your illness.
There are various ways to find help and support. Your hospital doctor, specialist nurse or GP can refer you to a counsellor.
If you're feeling depressed, talk to your GP. A course of antidepressant drugs may help, or your GP can arrange for you to see a counsellor or psychotherapist.
It can help to talk to someone who's been through the same thing as you. Many organisations have helplines and online forums. They can also put you in touch with other people who've had cancer treatment.
Complementary therapies are holistic therapies that can promote physical and emotional wellbeing.
They're given alongside conventional treatments and include:
Complementary therapy can help some women cope with diagnosis and treatment, and provide a break from the treatment plan.
Your hospital or breast unit may be able to provide access to complementary therapies or suggest where you can get them.
It's important to speak to your breast cancer specialist nurse about any complementary therapy you wish to use to make sure it doesn't interfere with your conventional treatment.
Most women with breast cancer have an operation as part of their treatment. Getting back to normal after surgery can take some time. It's important to take things slowly and give yourself time to recover.
During this time, avoid lifting things – for example, children or heavy shopping bags – and avoid heavy housework. You may also be advised not to drive.
Read more about recovering from an operation.
You may need to take a break from some of your normal activities for a while. Don't be afraid to ask for practical help from family and friends.
After your treatment has finished, you'll be invited for regular check-ups, usually every three months for the first year.
If you've had early breast cancer, your healthcare team will agree a care plan with you after your treatment has finished.
This plan contains the details of your follow-up. You'll receive a copy of the plan, which will also be sent to your GP.
You should also be offered a mammogram every year for the first five years after your treatment.
Although it's rare, your treatment for breast cancer may cause new problems, such as:
Talk to your healthcare team if you experience these or any other long-term effects of treatment.
A diagnosis of breast cancer may change how you think about your body. All women react differently to the bodily changes that happen as a result of breast cancer treatment.
Some women react positively, but others find it more difficult to cope. It's important to give yourself time to come to terms with any changes to your body.
Although most cases of breast cancer occur in women over 50 who have experienced the menopause, some younger women have to cope with an early menopause brought on by cancer treatment.
Symptoms can include:
Talk to your healthcare team about any symptoms you have and they'll be able to help.
An external breast prosthesis is an artificial breast, which can be worn inside your bra to replace the volume of the breast that's been removed.
Soon after a mastectomy, you'll be given a lightweight foam breast to wear until the area affected by surgery or radiotherapy has healed.
After it's healed, you'll be offered a silicone prosthesis. Prostheses come in many different shapes and sizes, and you should be able to find one that suits you.
If you didn't have immediate breast reconstruction carried out when you had a mastectomy, you can have reconstruction later. This is called a delayed reconstruction.
There are two main methods of breast reconstruction:
The type that's most suitable for you will depend on many factors, including the treatment you've had, any ongoing treatment, and the size of your breasts. Talk to your healthcare team about which reconstruction is suitable for you.
It's not always easy to talk about cancer, either for you or your family and friends. You may sense that some people feel awkward around you or avoid you.
Being open about how you feel and what your family and friends can do to help may put them at ease. However, don't be afraid to tell them that you need some time to yourself if that's what you need.
Breast cancer and its treatment can affect your sex life. It's common for women to lose interest in sex after breast cancer treatment.
Your treatment may leave you feeling very tired. You may feel shocked, confused or depressed about being diagnosed with cancer.
You may be upset by the changes to your body, or grieve the loss of your breasts or, in some cases, fertility.
It's understandable that you may not feel like having sex while coping with all this. Try to share your feelings with your partner.
If you have problems with sex that aren't getting better with time, you may want to speak to a counsellor or sex therapist.
If you have to reduce or stop work because of your cancer, you may find it difficult to cope financially.
If you have cancer or you're caring for someone with cancer, you may be entitled to financial support.
Find out what help is available to you as soon as possible. The social worker at your hospital will be able to give you the information you need.
People being treated for cancer are entitled to apply for an exemption certificate, giving them free prescriptions for all medication, including medicine for unrelated conditions.
The certificate is valid for five years, and you can apply for it through your GP or cancer specialist.
Your GP or nurse may be able to answer any questions you have about your cancer or treatment.
You may find it helpful to talk to a trained counsellor or psychologist, or someone at a specialist helpline. Your GP surgery will have information on these.
Some people find it helpful to talk to other people who have breast cancer, either at a local support group or on an internet chatroom.
As the causes of breast cancer aren't fully understood, it's not known if it can be prevented altogether.
Some treatments are available to reduce the risk in women who have a higher risk of developing the condition than the general population.
Studies have looked at the link between breast cancer and diet, and although there are no definite conclusions, there are benefits for women who:
Use our healthy weight calculator to check if you're a healthy weight.
It's also been suggested that regular exercise can reduce your risk of developing breast cancer by as much as a third.
If you've been through the menopause, it's particularly important that you're not overweight or obese. This is because these conditions cause more oestrogen to be produced by your body, which can increase the risk of breast cancer.
Studies have shown women who breastfeed are statistically less likely to develop breast cancer than those who don't.
The reasons aren't fully understood, but it could be because women don't ovulate as regularly while they're breastfeeding and oestrogen levels remain stable.
If you have an increased risk of developing breast cancer, treatment is available to reduce your risk.
Your level of risk is determined by factors such as your age, your family's medical history, and the results of genetic tests.
You'll usually be referred to a specialist genetics service if it's thought you have an increased risk of breast cancer. Healthcare professionals working at these services should discuss treatment options with you.
The two main treatments are surgery to remove the breasts (mastectomy) or medication. These are described in more detail below.
A mastectomy is surgery to remove the breasts. It can be used to treat breast cancer, and can reduce the chances of developing the condition in the small number of women from high-risk families.
By removing as much breast tissue as possible, a mastectomy can reduce your risk of breast cancer by up to 90%.
However, like all operations, there's a risk of complications, and having your breasts removed can have a significant effect on your body image and sexual relationships.
If you want to, you can usually choose to have a breast reconstruction either during the mastectomy operation or at a later date.
During breast reconstruction surgery, your original breast shape is recreated using either breast implants or tissue from elsewhere in your body.
An alternative is to use breast prostheses. These are artificial breasts that can be worn inside your bra.
An alternative to mastectomy is a nipple-sparing mastectomy, where the whole mammary gland is removed, but the skin envelope is preserved. This isn't widely available at the moment, but it's being used more often and can achieve excellent results.
Read more about your body and your breasts after treatment.
Three medicines are available on the NHS for women at an increased risk of breast cancer:
These medicines are usually taken once a day for five years. They can reduce your risk of breast cancer while you're taking them and possibly for several years afterwards.
Side effects of these medicines can include:
If your doctor suggests taking medication to reduce your breast cancer risk, ask them about the benefits and risks of each medicine.
The National Institute for Health and Care Excellence (NICE) has more on drug treatment to reduce the risk of breast cancer.
Emma Duncan was diagnosed with breast cancer twice in four years, once in each breast.
"I asked my GP if there was any screening programme they could put me into when I was 25, because my mother died from breast cancer when she was 32. They referred me to the Royal Victoria Infirmary, and I used to come once a year just for a check-up.
"A few years later I was in the bath and I noticed a lump under my left armpit. I didn't quite know what to make of it. I was quite worried at first.
"I went to see my GP the next day and he suspected that it might just be a cyst, as I was only 28 at the time. But because of my family history, he referred me to a specialist.
"At the hospital, I had an ultrasound, a mammogram and a needle biopsy. When I returned a week later for the results, they confirmed that I had breast cancer and that I would need to come in for lumpectomy surgery 10 days later.
"I had chemotherapy for six months after my first diagnosis, followed by five weeks of radiotherapy. It was really hard. All my hair fell out and it made me feel so ill.
"My husband Graham was great, and tried to support me as best he could throughout it. My sister-in-law was never off the phone and my best friend Claire was lovely.
"My sister handled it in a very different way. She had watched my mum become very poorly, and then her older sister was diagnosed. She found it hard to deal with and she just couldn't handle coming to see me. She later admitted being terrified that it might be her next.
"The second time I was diagnosed, I had a bigger operation – a double mastectomy. The decision to have a mastectomy was quite easy to make. For me, it was the only decision, having had cancer twice.
"The reality after the event was very different. With the reconstructive surgery as well, I knew it would be a long recovery, but I don't think anything prepared me for just how long. I cried every single day because I was so uncomfortable.
"I was referred to a psychologist, who told me I wasn't going mad. Anyone who'd been through what I had would be expected to have a few tearful days. Things settled down, then it was just a case of trying to get back to normal.
"Looking back at everything, I wouldn't have changed my decision at all. It was definitely for the best.
"I now have check-ups every six months with my oncologist, breast surgeons, and at the family clinic. I see my plastic surgeon, my geneticist, and have an ultrasound once a year, plus a blood test every four months as part of the ovarian screening programme.
"The Macmillan breast care nurses ring me up every once in a while to keep me up-to-date and check that I'm all right. I'm very well looked after.
"Now I just want to stay cancer free. I've done as much as I possibly can to prevent it from coming back or getting a new cancer. I didn't quite make it after my first diagnosis, but I'd like to get through the next five years without the cancer returning.
"The internet is full of horror stories, so make sure you get as much information as you can from reputable sources."