Male breast cancer

The information on this page will help you understand more about breast cancer in men including how it is diagnosed, treatment options and suggestions to help you cope with the disease.

We recommend that you read this along with our booklet Understanding Cancer of the Breast. Although this booklet is written for women, most of the information also applies to men.

How are men’s breasts different to women’s?

Often people are surprised to hear that men can get breast cancer. This may be because they do think of men as having breasts. In fact, both men and women have breast tissue. Until puberty, both girls and boys have similar breasts with some small ducts under the nipple. With the onset of puberty in girls, female hormones cause their breasts to grow and milk-producing glands or lobes are formed at the end of the ducts. In boys, male hormones prevent breasts from growing.

How common is breast cancer in men?

Breast cancer in men is very rare. About 18 -20 men are diagnosed with breast cancer each year in Ireland.

What are the causes of breast cancer in men?

As with breast cancer in women, the causes of male breast cancer are not fully known. However, there are some factors which might increase the risk:

  • Age: As with breast cancer in women, increasing age is the main risk factor. Most men who get breast cancer are over 60, although younger men can be affected.
  • High oestrogen levels: High oestrogen levels can occur as a result of chronic liver damage, obesity and some genetic conditions.
  • Obesity: Being very overweight (obese) seems to increase the risk of male breast cancer. This is especially so for men over 35 years of age. Obesity may be related to a higher oestrogen level in the body.
  • Kleinfelter's syndrome: This is a rare genetic condition where a man is born with an extra female chromosome. For men who have this syndrome the risk of breast cancer is 20 times greater than the average.
  • Radiation: Men who have had repeated and prolonged exposure to radiation can be at an increased risk of developing breast cancer. For example, radiotherapy treatment to the chest wall, particularly at a young age.
  • Significant family history or genetic link: Men with a significant family history of female breast cancer are also at a higher risk of breast cancer. This includes a mother or sister, particularly if the relative was under the age of 40 when diagnosed. About 5 per cent of all breast cancers in women are thought to have a genetic link. A genetic link in men seems to be more common.  For more information on family history call the National Cancer Helpline on Freefone 1800 200 700 and speak with a specialist nurse in confidence.

What are the symptoms of breast cancer in men?

The most common symptom of breast cancer in men is a painless lump in the breast. Other symptoms include nipple discharge (often blood-stained), a tender or pulled in nipple, ulceration or swelling of the breast. Occasionally, the lymph glands under the arm may also be swollen.

Because male breast cancer is rare, a man might ignore his symptoms and put off seeing his GP.  As a result, in some cases the cancer is already advanced when it is diagnosed. The earlier breast cancer is treated the better, so it is important to get any symptoms checked out as soon as possible.

How is a diagnosis made?

Once you have seen your GP (family doctor), you will be referred to a specialist breast unit where you will be seen by a doctor or specialist nurse. Following a physical examination of your breasts, you may have other tests such as:

  • A mammogram, which is an X-ray of the breast.
  • An ultrasound, which is a picture of the breast using sound waves.
  • A core biopsy, where a small piece of tissue is removed under a local anaesthetic and looked at under the microscope.

You may also have further tests to check that the cancer has not spread to other parts of your body. Click here for more information on the diagnosis of breast cancer.

What treatments will I be offered?

Treatment for men with breast cancer is the same as that for women. The treatment offered to you will depend on different factors such as the type of tumour, the stage of the disease and your general health. The main treatments used are surgery, chemotherapy, radiotherapy, hormone therapy and targeted therapies.


This is usually the first treatment but chemotherapy is given first in some cases. A mastectomy is most commonly done. This means that all the breast tissue is removed. It may also mean removing some of the underlying muscle if the cancer is at or close to it. Removal of the lump and surrounding tissue (wide local excision) is not usually possible because men only have a small amount of breast tissue. A sentinel lymph node biopsy is usually done at the time of surgery to find out if the cancer has spread to the lymph nodes in the axilla (glands in your armpit). Click here for more information on sentinel lymph node biopsies and surgery for breast cancer.


This treatment may be recommended to you before or after surgery. The aim is to reduce the risk of the cancer coming back. Click here for more information on chemotherapy and breast cancer.


The aim of radiotherapy is to reduce the risk of the tumour coming back in the treated area. It is usually given to the chest wall following a wide local excision and sometimes following a mastectomy. Click here for more information on radiotherapy for breast cancer.  

Hormone therapy

Oestrogen, which is mainly a female hormone, helps most male breast cancers grow. All men produce a very small amount this hormone so it is best to reduce the level of it in the body. This can be done by using hormone therapies. There are different drugs which work in different ways. Commonly used hormone therapies include:

  • Tamoxifen
  • Anastrozole (Arimidex®)

These drugs can cause some side-effects, such as less interest in sex and problems having an erection. Other common side-effects include hot flushes and sweats, loss of energy and headaches

If you are having any of these side effects, tell your doctor as help is available. Click here for more information on side effects for men with breast cancer (external link)

Biological therapies

Biological therapies work by blocking the growth and spread of cancer by changing the biology of cancer cells. The most well-known biological therapy is a drug called trastuzumab (Herceptin®). Trastuzumab is only suitable if your cancer has high levels of HER2, a protein that encourages cancer cell growth. Click here for more information on biological therapies for breast cancer.

What if my cancer has spread to another part of my body?

If your cancer has spread to another part of your body, this is called advanced or secondary breast cancer. You will be offered treatment to help control the disease. Your doctor may offer chemotherapy, hormone therapy, biological therapies or a combination of these treatments. Click here for more information on secondary breast cancer.

Coping with breast cancer

Being diagnosed with breast cancer can be an anxious and frightening time. At different times during your diagnosis and treatment you may experience a range of emotions such as shock, disbelief or anger. These feelings are common but everybody responds differently and has their own way of coping.

You may find it particularly difficult because breast cancer is usually associated with women. You may feel embarrassed about discussing your diagnosis with others. You may also feel very much alone. Whatever your circumstances, try not to bottle up your feelings or cope on your own. Remember that there are people who can support you, so don’t be afraid to ask for help.

You might find it helpful to read our booklets including Understanding Cancer of the Breast and Who Can Ever Understand: Talking About Your CancerLost for words: How to talk to someone with cancer and Understanding the emotional effects of cancer: A guide for patients.

Many people find that they can get back some sense of control by finding out as much as possible about their condition and treatment. It is important that you feel you can talk to your specialist or breast care nurse about any questions or concerns you may have.