Breast cancer

Breast cancer occurs when the cells that line the ducts or lobules in your breasts start to grow abnormally and multiply in an uncontrolled way to form a tumour.

There are different types of breast cancer, but it’s most often found in the milk ducts and is usually invasive — this is called invasive ductal cancer. Other types of breast cancer include:

• Inflammatory breast cancer
• Invasive lobular breast cancer
• Paget’s disease

Sometimes breast cancer spreads to the lymph glands and to other parts of the body. This is called metastasis and is harder to treat.

Around one in eight women will get breast cancer in their lifetime. Women in the UK between the ages of 50 and 71 are offered a mammogram every three years. With screening and being aware of changes in your breasts, it’s possible to find and treat breast cancer early. This can mean a good outcome for many women. 

In rare cases, men can also develop breast cancer. 

Breast cancer usually develops in the cells lining the milk ducts. The main breast cancer symptoms are:

• A lump or thickened area in your breast or under your armpit — this is usually the first symptom women notice; although breast lumps are usually not cancer, it is important to get them checked by a doctor
• A rash around your nipple
• Change in the size or appearance of your breast or nipple eg your nipple may sink into your breast tissue
• Constant pain in or around your breast
• Leaking from your nipple — discharge may be streaked with blood
• Puckering or dimpling of the skin of your breast  

By checking your breasts regularly you’ll be able to spot if something seems different. 

These signs are often caused by normal changes in your breast and not breast cancer but you should still see your GP if you experience any of them.

Your GP will examine your breasts and the lymph nodes under your arms and by your neck. They’ll ask about your family history and if you’re taking hormone replacement therapy (HRT) or the contraceptive pill, or if you’ve had previous breast surgery.

They may refer you to a breast clinic for:

• Mammogram — uses X-rays to image your breast tissue; although it may not detect all breast cancers it is the most widely available test to pick up the early signs of breast cancer
• Ultrasound scan — uses high-frequency sound waves to image your breast tissue; usually recommended in women under age 35 as younger women have more dense breast tissue, which makes it harder for a mammogram to detect breast cancer 

They may take a sample of your breast cells (biopsy) to check if they are cancerous. This can be done with:

• A core biopsy — a local anaesthetic is applied to numb your breast before a large needle is inserted to collect a sample of breast tissue; this may be carried out with the help of an ultrasound or X-ray to more precisely target where the tissue is collected from 
• Fine needle aspiration — a small needle is inserted into your breast to collect some of your breast cells; this can also be used to drain a breast cyst (benign lump in your breast)

You may have these tests repeated if you’ve been recalled back from a routine screening. This is often because the results of a previous mammogram weren’t clear but it may mean there were signs of breast cancer.

If you’re diagnosed with breast cancer, your doctor will be able to tell you the stage and grade of your cancer. To see if your cancer has spread you may also need a:

• • CT scan
  • PET/CT scan

There are several types of breast cancer and two main groups — non-invasive and invasive breast cancers. 

Non-invasive breast cancers 

Non-invasive breast cancers haven't spread into the breast tissue surrounding the tissue that they developed in ie the milk ducts or milk-producing glands. The two types of non-invasive breast cancer are: 

• Ductal carcinoma in situ (DCIS) — develops in the milk ducts of your breast and doesn't usually cause a noticeable lump in your breast; it is usually detected during a mammogram
• Lobular carcinoma in situ (LCIS) — ​develops in the milk-producing glands (lobules) of your breast

Invasive breast cancer 

This type of breast cancer has spread through the lining of the milk ducts or lobules into the surrounding breast tissue. It often has no special features when the cells are looked at under the microscope — in these cases, which make up 70% of all breast cancer cases, it is called invasive breast cancer ‘no special type’ (NST).

Other types of breast cancer

The most common types of breast cancer start in the milk ducts or lobules and are usually invasive. However, there are several other less common types of breast cancer, including: 

Inflammatory breast cancer

This is an aggressive type of breast cancer that progresses quickly. However, it is rare, making up just 1-5% of all breast cancer cases. Cancer cells don't form a tumour but instead block the lymph nodes near your breast. This stops the lymph vessels from draining properly, which causes your breast to become red, swollen and warm to the touch. The surface of your breast may also look pitted — often described as looking like orange peel.

Triple negative breast cancer

This type of breast cancer makes up 10-20% of all breast cancer cases. It is described as triple negative because the tumours do not have: 

• Extra HER2 proteins on the surface of their cells — this protein helps tumours grow
• Oestrogen receptors — these are proteins on the surface of cells that attach to the hormone oestrogen; tumours with oestrogen receptors grow in response to oestrogen
• Progesterone receptors — these are proteins on the surface of cells that attach to the hormone progesterone; tumours with progesterone receptors grow in response to progesterone

Triple negative breast cancer grows and spreads more quickly than other types of breast cancer and is harder to treat with traditional breast cancer therapies. This is because these therapies target hormones, which triple negative tumours do not respond to. 

Metastatic breast cancer

It's possible for breast cancer to spread to other parts of the body, usually through the blood or the axillary lymph nodes (small lymphatic glands that filter bacteria and cells from the mammary gland). If this happens, it's known as secondary, stage 4 or metastatic breast cancer — this type of breast cancer is advanced.

Metastatic breast cancer spreads to other parts of your body, such as your bones, lungs and liver.

Invasive (and pre-invasive) lobular breast cancer

Around 15% of all breast cancer cases are invasive lobular carcinoma. They develop in the lobules (milk-producing glands) of your breast. 

Paget's disease of the breast

This is a very rare type of breast cancer, which affects the nipple and areola of the breast. The first noticeable symptom is usually a rash affecting the nipple and areola that looks similar to eczema. 

Phyllodes tumour

This is a very rare and aggressive type of breast cancer. It develops in the stromal cells around the milk ducts of the breast. 

Breast angiosarcoma

This type of cancer develops in the cells lining blood vessels or lymph vessels of the breast. It is rare and can develop as a compilation of radiation treatment of the breast. 

Male breast cancer

Men have less breast tissue than women and are much less likely to develop breast cancer. Although male breast cancer is rare, it is just as serious as breast cancer in women and has the same symptoms. 

In most cases, the cause of breast cancer is unknown although there are several risk factors. 

About 70% of breast cancers are linked to the presence of the female hormone oestrogen in your body. Most breast cancers happen by chance and the biggest risk factor is age — the older you get, the higher your risk, with breast cancer most commonly affecting women aged over 50.

Other risk factors for breast cancer are:

• A family history of breast cancer — although less common, some women carry a gene mutation that makes them more likely to develop breast cancer
• A previous diagnosis of breast cancer or a non-cancerous (benign) lump in your breast 
• Having late menopause, starting your periods before the age of 12, not ever being pregnant or being pregnant at an older age — this means you’ve been exposed to oestrogen for longer
• Lifestyle factors — this includes: 
• Being overweight or obese
• Drinking too much alcohol 
• Smoking 
• Previous radiotherapy or radiation exposure to your chest
• Taking hormone replacement therapy (HRT) or the contraceptive pill, although this depends on other things such as your age and how long you take it

Taller women and women with dense breast tissue also have a higher risk of developing breast cancer. 

Treatment depends on the type of breast cancer and whether it’s localised inside your breast or has spread to other parts of your body. 

Surgery is usually the first treatment offered to remove a lump or cancerous tissue before it spreads. There are different types of surgery, including: 

• Lumpectomy to remove the tumour and some surrounding tissue, while leaving the rest of the breast intact
• Mastectomy to remove the entire breast — a double mastectomy removes both breasts
• Sentinel node biopsy to remove several of the lymph nodes that the tumour drains into so the tissue can be checked for cancer cells — if cancers cells are found you may need more surgery
• Axillary lymph node dissection to remove additional lymph nodes after cancer is detected from a sentinel node biopsy 
• Contralateral prophylactic mastectomy to remove a healthy breast after a mastectomy to remove a cancerous breast — some women decide to have this done to reduce the risk of cancer returning in the other breast

If you have metastatic breast cancer, the focus of treatment is to relieve symptoms as this type of cancer can’t be cured.  

Whichever type of breast cancer you have, you may also be offered:

Bisphosphanates 

These drugs can help reduce the chances of your breast cancer spreading and returning, and protect your bones from thinning as a side effect of certain breast cancer treatments. 

Bisphosphonates, such as clodronate and zoledronic acid, reduce the risk of breast cancer spreading to your bones and are often taken for three to five years. They are usually recommended if your cancer has a high chance of returning and you have gone through menopause or had treatment to stop your ovaries from working. 

Chemotherapy 

These drugs help destroy any cancer cells that spread to other parts of your body through your blood or lymph fluids. It is usually used alongside other treatments such as surgery. You may have chemotherapy before and/or after surgery. When given before surgery, it is used to shrink the tumour so that surgery to remove the tumour will be less invasive. 

Chemotherapy has many side effects. Your doctor will talk to you about these and there is support available to help you cope with these side effects. 

Hormone therapy 

These drugs target the female hormones oestrogen and/or progesterone, which, in certain types of cancer, promote the growth of the tumour. Hormone therapy can stop your body from producing these hormones or can block the hormone receptors on cancer cells, which attach to these hormones and trigger tumour growth. 

Hormone therapy can slow tumour growth and in some cases, stop tumour growth. 

Radiotherapy

Radiotherapy helps destroy any remaining cancer cells around the area of your breast. It involves the use of high-powered radiation beams targeted at your breast tissue. Radiotherapy is usually given externally from a machine that generates the radiation beams. 

However, in advanced cancer cases, you may need radiotherapy applied from inside your body — this is called brachytherapy. Brachytherapy involves surgery to place radioactive seeds or pellets inside your body near the site of your tumour. These seeds or pellets emit radiation over time.

Targeted therapy 

These drugs target very specific actions inside a cancer cell to stop it from multiplying.

Targeted therapy, such as the drug trastuzumab, is commonly used to treat HER2-positive breast cancer in men and women. Trastuzumab is usually given alongside chemotherapy, before or after surgery, to reduce the chances of breast cancer returning. 

Another targeted therapy called pertuzumab may be used alongside trastuzumab if there is a high risk of your HER2-positive breast cancer returning. Both pertuzumab and trastuzumab attach to HER2 proteins on the surface of cancer cells to stop these cells from multiplying. 

Breast cancer can affect your daily life both physically during treatment and emotionally. To help you cope with your diagnosis, it is important to lean on your support systems, such as friends and family, or other people with breast cancer who you can connect with through support groups. 

It may also help to find out as much as you can about your type of cancer. Try to relax and make time for yourself as much as possible and avoid overexerting yourself. 

Breast cancer survival rates are generally good. This is due to improved breast cancer screening, which leads to early treatment, as well as improved treatments. The sooner your cancer is caught, the better your chances of successful treatment.

Breast cancer stages and survival rates

There are no UK-wide statistics on breast cancer survival according to different treatments. The following data is therefore based on survival rates in England five years after breast cancer diagnosis and according to breast cancer stage. 

Stage 0

Stage 0 breast cancers are non-invasive. This means that they haven't spread into the breast tissue surrounding the tissue that they developed in ie the milk ducts or milk-producing glands (lobules). They are referred to as carcinoma in situ. 

The survival rate five years after diagnosis is over 98% for stage 0 breast cancers. 

Stage 1

Stage 1 breast cancers can be divided into two categories: 

• Stage 1A — the tumour is 2 cm wide or less and your lymph nodes aren't affected
• Stage 1B — the tumour is 2 cm wide or less or there is no tumour in the breast but cancer is present in nearby lymph nodes 

The survival rate five years after diagnosis is around 98% for stage 1 breast cancers. 

Stage 2

Stage 2 breast cancers can be divided into two categories: 

• Stage 2A — the tumour is less than 2 cm and cancer has spread to one to three lymph nodes nearby or the tumour is 2-5 cm wide but the lymph nodes aren't affected
• Stage 2B — the tumour is 2-5 cm wide and cancer has spread to one to three lymph nodes in your armpit (axillary lymph nodes) or the tumour is more than 5 cm wide but the lymph nodes aren't affected

The survival rate five years after diagnosis is around 90% for stage 2 breast cancers. 

Stage 3

Stage 3 breast cancers can be divided into three categories: 

• Stage 3A — the tumour can be of any size and cancer has spread to four to nine axillary lymph nodes or has caused the internal mammary lymph nodes to become enlarged, or the tumour is more than 5 cm wide and cancer has spread to one to three axillary lymph nodes or the breastbone lymph nodes
• Stage 3B — the tumour has invaded the chest wall or skin and cancer may or may not have spread to up to nine lymph nodes
• Stage 3C — cancer has spread to 10 or more axillary lymph nodes, lymph nodes near the collarbone or internal mammary nodes

The survival rate five years after diagnosis is over 70% for stage 3 breast cancers. 

Stage 4

The tumour can be of any size and cancer has spread to nearby and distant lymph nodes and distant organs. 

The survival rate five years after diagnosis is around 25% for stage 4 breast cancers. Stage 4 breast cancer is not curable. This means your life expectancy will be reduced. Treatment aims to control your symptoms. 

In most cases, the cause of breast cancer is unknown. It is therefore not possible to prevent it. However, risk factors for breast cancer have been identified and if you are at a high risk of developing breast cancer, there are treatments to reduce your risk such as a preemptive mastectomy. 

Preemptive mastectomy

If your mother or father has a genetic mutation in the BRCA1 or BRCA2 gene, you have a greater risk of developing breast cancer. You can speak to your doctor and get a genetic test to see if you also carry the genetic mutation. If you do, you can discuss preemptive treatment with your doctor — this may include the preemptive removal of your breasts ie a double mastectomy. 

Lifestyle changes

There is no clear evidence on the effects of changing your diet and your risk of developing breast cancer. However, it is thought that making the following lifestyle changes may help:

• Exercising regularly — this may also improve outcomes for women who already have breast cancer
• Following a diet low in saturated fats
• Maintaining a healthy weight — this is particularly important if you have been through menopause as being overweight or obese increases oestrogen production, which can increase your risk of breast cancer
• Not drinking alcohol

Breast screening

The UK has a national screening for breast cancer, which is offered to women aged 50-71. It involves having a mammogram every three years. 

If you are at high risk of developing breast cancer eg if you carry a BRCA1 or BRCA2 gene mutation or have a family history of breast cancer, you may be offered breast screenings before age 50. 

After age 71, you will no longer be invited for regular mammograms, however, you can still have them.

Breast examination

Regular self-examinations of your breast, once a month, can help you detect any changes that could be signs of breast cancer. It is important to carry out your self-examination at the same time each month, as your period can cause changes in how your breasts feel. 

If you are concerned about potential signs of breast cancer in your breasts, your doctor may perform a physical examination of your breasts as well. You can request that a chaperone be present during your examination.