Possible treatments include surgery, radiotherapy and medicines.
You'll be cared for by a team of specialists who will help you make decisions about your treatment.
Your recommended treatment plan will depend on how far the cancer has spread. The final decision about going ahead with treatment is yours.
You may find it useful to write a list of questions you'd like to ask your team. For example, you could ask about the advantages and disadvantages of particular treatments.
If the cancer has not spread very far beyond your breast, a cure may be possible. This will usually involve surgery, possibly followed by radiotherapy or a course of medicine.
If the cancer has spread into other parts of your body, a complete cure may not be possible. But treatment can help relieve symptoms and slow down the spread of the cancer.
Surgery
An operation called a mastectomy is the main type of surgery for breast cancer in men.
It involves removing all the breast tissue from the affected breast as well as the nipple, and possibly also the glands in your armpit and some of the muscle under your breast.
The operation is done under a general anaesthetic (where you're asleep). You'll probably need to stay in hospital for 1 to 2 days.
It can take several months to fully recover.
Your body after surgery
After surgery, there'll be a straight scar across your chest where your nipple used to be and possibly a dent where the breast tissue was removed.
The scar will be raised and red at first, but it should flatten and fade with time. The area will also be bruised and swollen for a few weeks.
It may be possible to have further surgery at some point to improve the appearance of your breast and create a replacement nipple. Other options include tattooing a new nipple on to your chest.
Talk to your care team about how your chest will look after surgery and what options you have for improving its appearance if necessary.
Possible complications
Side effects and risks of a mastectomy include:
- pain and discomfort for 1 to 2 weeks - you'll be given painkillers to help with this
- numbness or tingling around the scar and in your upper arm - this should pass within a few weeks or months, but can occasionally be permanent
- a wound infection, causing redness, swelling, warmth or discharge from the wound – tell your nurse or doctor if you get any of these symptoms
- painful swelling in your arm (lymphoedema) - this may be permanent, but can be treated.
Before having surgery, talk to your surgeon and breast care nurse about the possible risks.
Radiotherapy
Radiotherapy is a treatment where radiation is used to kill cancer cells. In breast cancer in men, it may be used to:
- help stop the cancer coming back after surgery
- slow down the spread of the cancer and relieve symptoms if a cure is not possible
It involves several treatment sessions where a machine is used to carefully aim beams of radiation at the cancer. Each session usually lasts for 10 to 15 minutes and you can go home afterwards.
A typical course of treatment involves 2 to 5 sessions each week over 3 to 6 weeks.
Side effects
Radiotherapy is not painful, although you'll probably get some side effects. Most of these should pass when treatment stops.
Common side effects of radiotherapy include:
- sore, red skin (similar to sunburn) on your chest
- feeling very tired
- feeling sick
- temporary hair loss in the area of your chest being treated
Hormone therapy
Hormone therapy is a treatment that involves taking medicine to block the effects of a hormone called oestrogen.
Around 9 in 10 breast cancers in men are oestrogen receptor positive, which means the cancer cells need oestrogen to grow.
Hormone therapy can be used to:
- help stop the cancer from coming back after surgery
- slow down the spread of the cancer and relieve symptoms if a cure is not possible
Tamoxifen
The most commonly used hormone medicine is tamoxifen. This is taken as a tablet or liquid every day, usually for 5 years, but sometimes for longer.
Tamoxifen can cause some unpleasant side effects, such as:
- feeling sick (this usually goes away quite quickly)
- hot flushes
- weight gain
- difficulty sleeping
- changes in mood, such as feeling irritable or depressed
- loss of sex drive (libido)
Tell your care team if you have any troublesome side effects. Other hormone medicines, such as a type called aromatase inhibitors, are available if needed.
Chemotherapy
Chemotherapy is a treatment where powerful medicine is used to kill cancer cells. It may be used if hormone therapy is not suitable for you.
In breast cancer in men, chemotherapy may be used to:
- help stop the cancer coming back after surgery
- slow down the spread of the cancer and relieve symptoms if a cure is not possible
It involves several treatment sessions where medicine is given directly into a vein. Each session usually lasts a few hours and you can go home afterwards.
A typical course of treatment involves 6 sessions, with a break of a few weeks between each one to allow your body to recover.
Side effects
Chemotherapy can cause a range of unpleasant side effects, although most of these should pass once treatment stops.
Side effects of chemotherapy can include:
- feeling very tired
- feeling and being sick
- temporary hair loss
- being more vulnerable to infections – tell your care team if you feel unwell or develop symptoms such as a fever and chills
- loss of appetite
- diarrhoea
- infertility
Trastuzumab (Herceptin)
Trastuzumab (brand name Herceptin) is a medicine that blocks the effect of a substance called human epidermal growth factor receptor 2 (HER2).
In some breast cancers in men, HER2 helps cancer cells grow.
Trastuzumab is usually used after radiotherapy or chemotherapy to help stop the cancer coming back.
It's given as a liquid directly into a vein, or as an injection under your skin. You go into hospital for treatment and can go home shortly afterwards.
A typical course of treatment involves a treatment session every 3 weeks for a year.
Side effects
Trastuzumab can cause some unpleasant side effects, such as:
- a reaction to the medicine – this can cause chills, a fever, swelling of your face and lips, headaches, hot flushes, feeling sick, wheezing and breathlessness
- tiredness and difficulty sleeping
- diarrhoea or constipation
- an increased risk of infections
- loss of appetite and weight loss
- pain in your muscles, joints, chest or tummy
- heart problems