Breast swelling in men | Cancer Research UK
Cancer Research UK on Google+ Cancer Research UK on Facebook Cancer Research UK on Twitter

Breast swelling in men

This page is about breast swelling in men caused by hormone treatment for cancer. There is information about


Hormones, breast swelling and cancer

Some cancer treatments lower sex hormone levels in the body. The hormone affected in men is testosterone. Low testosterone levels can cause breast swelling in men.


What breast swelling is

Doctors call breast swelling in men gynaecomastia (pronounced guy-nee-co-mass-tee-ah). Swelling can develop in one or both breasts. Most men also have some breast pain. The pain may be constant, needing painkillers, or it may be mild. The initial swelling is fatty tissue. But if it is not treated the breast tissue can become more dense and fibrous. This makes it more difficult to treat.

Breast swelling and breast pain can be very distressing and difficult to cope with. Many men feel embarrassed and feel less confident about themselves when they have it. If you notice that you have any swelling tell your doctor or specialist nurse. A number of treatments can help.

man visiting a GP

To make a diagnosis your doctor may arrange for you to have an ultrasound scan. This helps to confirm the breast swelling and rules out any other problems. It also helps to find out the depth of swelling so the doctor can work out the best treatment for you.


What causes breast swelling

This page is about breast swelling caused by cancer treatment medicines. Hormone treatment is one of the main treatments for prostate cancer. Prostate cancer depends on the hormone testosterone to grow. So reducing the amount of testosterone in the body means that a cancer may shrink or grow more slowly. There are different ways of reducing the amount of testosterone in the body. You can find out about hormone therapy for prostate cancer and how it works. 

When testosterone levels fall, the amount of oestrogen compared to testosterone changes. This means that oestrogen then has more influence on the body. Oestrogen stimulates growth of breast tissue. Oestrogen is often thought of as a female hormone but the adrenal glands make a small amount of oestrogen in men.

Some hormone treatments for prostate cancer increase the risk of breast swelling more than others. Anti androgen hormone therapies such as bicalutamide cause breast swelling in about 1 in 2 men (50%). They cause breast tenderness or pain in up to 3 out of 4 men (75%).

Breast swelling is much less common with luteinising hormone releasing hormone drugs, such as goserelin and leuprorelin. 

About 1 in 10 men (10%) who have had their testicles removed (orchidectomy) have breast swelling.


Treatment for breast swelling

There are a number of different treatments for breast swelling (gynaecomastia). Before you start hormone treatment for your prostate cancer, your doctor may suggest one of these treatments.


Doctors occasionally use radiotherapy to prevent or treat breast swelling and pain caused by the hormone therapy drug bicalutamide. Most men only need to have one or two treatments with low doses of radiotherapy to the breast area. This treatment does not work for all men. Side effects include sore, red skin in the treated area, which lasts for a few weeks. There is also a small risk of developing cancer in the radiotherapy area some years after the treatment. 

Hormone treatment

Your doctor may suggest hormone blocker treatment if you are having bicalutamide. These treatments either block oestrogen from stimulating the breast cells to grow or stop the body changing testosterone into oestrogen.

Tamoxifen is a hormone treatment used for breast cancer. It works by blocking oestrogen. Tamoxifen can prevent and reduce breast swelling and breast pain in most men having bicalutamide treatment for prostate cancer.

Aromatase inhibitors (AIs) stop the body from changing male hormones into oestrogen in the fatty tissues of the body. Aromatase inhibitors include the drugs anastrozole, exemestane and letrozole. We know from research that AIs can reduce breast swelling and pain but we need to know more about exactly how well they work.

We need more research to find the best way of treating male breast swelling and pain with hormone blockers. We need to find the best treatment and the best dose, and get more information about side effects. So far there is no evidence that this type of treatment makes hormone treatment for prostate cancer work less well, but we need more research to confirm this.

Comparing radiotherapy and tamoxifen

Research comparing radiotherapy with tamoxifen suggests that tamoxifen works better. But doctors and researchers always try to balance how well a treatment works with the risk of side effects,  There are disadvantages to tamoxifen. It is a tablet you have to take once a week whereas radiotherapy is a one off treatment. There is some concern about whether tamoxifen may make hormone treatment for prostate cancer work less well. We need more research to compare the treatments using slightly larger radiotherapy treatment areas, which researchers suggest may make it as good as tamoxifen. But there is also a small increase in the risk of cancer in the radiotherapy treatment area some years later.

Surgery to remove breast tissue

Surgery for breast swelling means that the surgeon removes the excess breast tissue. The surgeon makes a cut (incision) around the nipple to leave it in place and minimise any scarring. Problems from this type of surgery can include

  • Bleeding
  • Flattening around the nipple
  • An inpointing nipple (inverted nipple)
  • Loss of feeling in the breast

Another way of removing breast tissue is to suck out excess fatty tissue with liposuction. It works best on breast swelling that is at an early stage. But breast swelling caused by drug treatment for prostate cancer tends to include a build up of glandular tissue. The glandular tissue is denser and firmer than fatty tissue and liposuction doesn’t work with this type of tissue.

Some doctors suggest that a combination of surgery to remove the glandular tissue and liposuction to remove fatty tissue may be best for men having hormone treatment. In a trial, men were happy with the results of this treatment combination as it tends to leave a smooth chest. Surgery alone can leave a slightly indented chest. The men in the trial also had fewer problems after the combined treatment than after surgery alone.

Rate this page:
Submit rating


Rated 5 out of 5 based on 9 votes
Rate this page
Rate this page for no comments box
Please enter feedback to continue submitting
Send feedback
Question about cancer? Contact our information nurse team

No Error

Updated: 26 June 2015