What is breast cancer?

Breast cancer starts when cells in the breast start to grow and divide out of control. Breast cancer can be in one breast or both and start in different areas of the breast. The most common areas are the ducts that carry milk to the nipples, or the milk-producing glands called lobules.

Anyone can get breast cancer. However, breast cancer is more common in breasts that can produce milk.

The parts of the breast

Types of male breast cancer

All people are born with breast cells and tissue. While people assigned male at birth do not develop breasts that can produce milk, their breast cells and tissue can still develop cancer. 

There are different types of breast cancer. Your doctor will decide the best treatment plan for you based on the type of breast cancer you have.

Types include:

• Invasive ductal carcinoma (IDC): Invasive means the cancer has spread to surrounding breast tissues. IDC occurs when cancer in the milk ducts spreads to nearby breast tissue. Milk ducts are tubes that carry milk from the lobules (glands that make milk) to the nipple.
• Ductal carcinoma in situ (DCIS): DCIS is a type of breast cancer found in the lining of the milk duct. Early breast cancer known as "carcinoma in situ" has not spread to other areas.
• Invasive Lobular Carcinoma (ILC): ILC occurs when cancer in the lobules spreads to nearby breast tissue. Lobules are the glands in the breast that make milk. This cancer is rare because people born male have few lobules in their breast tissue. 
• Inflammatory breast cancer: This cancer blocks lymph vessels. Lymph vessels are small, hollow tubes that allow lymph fluid to drain out of your breast. This is a rare type of cancer, but one that grows and spreads quickly.
• Paget disease of the nipple: This cancer occurs when cancer grows from the ducts below the nipple. The cancer cells spread to the surface of the nipple and extend to the dark circle of skin (areola) around the nipple.

Causes of male breast cancer

The cause of breast cancer is unclear. Some of the factors that might increase your chances of developing cancer are:

• age – male breast cancer is more common if you are 60 years of age or older
• family history – if you have close family members with breast cancer, you have a higher risk of developing breast cancer. For more information see the video Understand Hereditary Cancer
  
• genetic mutations (changes) – abnormal change in genes such as the BRCA 1 or BRCA2 gene
• past treatments with radiation therapy – radiation to the chest area can increase the risk of breast cancer.
• high levels of estrogen – diseases that produces high levels of the hormone estrogen such as liver cirrhosis or Klinefelter syndrome
• hormone replacement therapy – using medicines that contain estrogen (a hormone that helps develop and maintain female features)
• testicle disease or surgery – inflamed or swollen testicles or having surgery to remove one or more testicles (testicles are glands that produce sperm and hormones)

How is male breast cancer diagnosed?

Your doctor will do tests to diagnose breast cancer. These tests give information to help your cancer care team develop a treatment plan for you:

• breast exam – your doctor examines and feels your chest to find any lumps or changes in the breast tissue
• breast ultrasound – uses sound waves to build a picture of the breast. For more information see Preparing your Breast Ultrasound
• mammogram – x-ray pictures of the breast tissue find lumps and any abnormal growths
• MRI (magnetic resonance imaging) – a detailed image of a certain area in your body. For more information see Preparing for your Magnetic Resonance Imaging (MRI)
• biopsy – your doctor takes a small sample of breast tissue and sends it to a lab to test if cancer cells are in the tissue

If cancer cells are found in the sample, the lab will check the receptor status of the cancer cells. The receptor status tells your doctor whether the cancer is using certain hormone or proteins in your body to grow. For more information on receptor status, read the brochure Learn How Breast Cancer Receptor Status Guides Treatment .

If the ultrasound shows there may be cancer in the lymph nodes, you will have a biopsy of the lymph nodes. Lymph nodes are small, bean-shaped organs that are part of the body's immune system.

Breast cancer cells can spread into the lymph nodes or bloodstream. Once in the lymph node or bloodstream, cancer cells can metastasize (spread) throughout the body. For more information about lymph nodes and lymph node surgery, read Your Guide to Having Breast Cancer Surgery.

Will I need extra tests?

You will have extra tests if imagining shows:

• your tumour is a certain size
• there is cancer in many lymph nodes
• the tumour is a certain size and there is cancer in many lymph nodes

These tests show if the cancer spread to other parts of the body. Your doctor will also order extra tests if you have new symptoms not related to other conditions (for example, pain, shortness of breath).

Not everyone needs these tests. These tests are not usually done on patients with Stage 1 or 2 breast cancer.  Stage 1 cancer means the breast cancer is small and has not spread anywhere else.  Stage 2 means the tumour is larger than at stage 1 and may have spread to a few nearby lymph nodes. These tests only look for cancer that has spread to the rest of the body.

Extra tests can include:

• blood tests to check your general health and kidneys
• a bone scan to check if cancer has spread to areas in your bone.  For more information see Bone Scan
• a CT scan to see where a tumour is located, how big it is, and what the blood vessels feeding the tumour look like
• a PET scan to check if cancer has spread to the lymph nodes and other parts of the body. PET scans also show if the treatment is working. For more information about a PET and CT scans see PET and CT Scans

Treatment

Your cancer treatment depends on:

• receptor status of the cancer
• stage (the size of the tumour and how far the cancer has spread)
• grade (how different the cancer cells are from healthy cells)
• what treatment option you prefer

Treatment usually involves surgery to remove the cancer. You may also get other treatments such as chemotherapy, radiation therapy and hormonal therapy.

Surgery

The 2 types of surgery are Mastectomy (removing the whole breast) and Lumpectomy (removing a part of the breast).

Mastectomy is the most common type of surgery for male breast cancer. Your doctor will discuss with you which option is right for you.

Treatment options after surgery

The treatments and the order you may get them are based on your cancer.

• Radiation therapy (also called external beam radiation therapy) uses high-energy radiation to kill cancer cells. It works by damaging and killing the cells in the treatment area.
• If you had a lumpectomy, you may need radiation treatment after surgery. It will help lower the chance that the cancer will come back.
• If you had a mastectomy, you may need radiation treatment after surgery. You may need radiation treatment if the cancer is large or if the cancer is found in the lymph nodes or other areas of the body.

• Chemotherapy (also called "chemo") is a common cancer treatment that uses medicines to kill cancer cells. Chemotherapy is a systemic therapy, which means it travels through your blood to reach cells throughout your entire body. Chemotherapy may include one medicine or combine a few medicines. Your healthcare team may use chemotherapy on its own or as part of other treatments.
• Hormone therapy (also known as endocrine therapy) lowers the amount of estrogen in your body. This blocks estrogen from causing breast cancer cells to grow.

Your doctor will discuss with you which treatment option is right for you. For more information about other treatment options visit Health Information > Medical Tests and Treatments.

How long will my treatment be?

It will take between 2 to 4 weeks to recover from surgery. It may take you longer to heal if lymph nodes are removed.

Your healthcare provider can tell you how long your treatment should take. Recovery from chemotherapy, radiation therapy, targeted therapy or immunotherapy may take

weeks to months. How long your recovery takes will depend on the where the tumour is and the stage of the tumour.

What questions should I ask my healthcare provider about male breast cancer?

These questions can help you think about what you would like to know after you get your diagnosis (told you have cancer).

• What do "staging" and "grading" mean? What stage and grade of cancer do I have?
• What are my treatment options?
• What are the reasons for and against these treatment options?
• How long will my treatment take?
• What are the short-term side effects of the treatments?
• What are the long-term side effects of the treatments?
• What signs or symptoms should I tell you about?
• Do you expect to cure my cancer with these treatments? If not, what is the goal of these treatments?
• How can I prepare for my treatment appointment?
• What can I do to prevent or manage side effects?
• Will I be able to do my normal activities?
• Will this treatment affect my sex life?
• Will this treatment affect my ability to have children? If so, is there fertility preservation options available?
• Do I need follow-up care?
• Will my cancer come back?
• Are there support groups or resources I can turn to?

See My Questions  for more questions you may want to ask your cancer care team.