Over the 10 years, the researchers noted a steady increase in the rates of total mastectomy and contralateral prophylactic mastectomy, which is when a surgeon removes a healthy breast as a preventive measure. To investigate, the scientists accessed data from the National Cancer Database. They scrutinized the records of men diagnosed with stage 1–3 breast cancer from 2004–2014. In total, the study included data from 10,873 men.
The average age of diagnosis was 64, and 51% of diagnoses occurred between the ages of 50 and 69. Only 15% received a diagnosis before the age of 50.
Types of tumours
A cancerous tumour of the breast can spread (metastasize) to other parts of the body. Cancerous tumours are also called malignant tumours.
Almost all of the breast cancers found in men are ductal carcinoma. This type of cancer starts in gland cells in the lining of a duct. Doctors will classify these tumours as non-invasive or invasive. Non-invasive means that the cancer cells have not spread beyond the duct where they started. Invasive means that the cancer cells have started to grow through the wall of the duct and into the surrounding tissue.
Most ductal carcinomas in men are invasive. After they grow through the duct, the cancer cells can continue to grow and cause a lump or thickening in the breast. The breast cancer cells can also spread to lymph nodes and other parts of the body. Other types of breast cancer can also develop in men, but they are rare. These types of breast cancer are treated the same way in men as they are in women.
A risk factor is something that increases the risk of developing cancer. It could be a behaviour, substance or condition. Most cancers are the result of many risk factors. But sometimes breast cancer develops in men who don’t have any of the risk factors described below. The risk of a man developing breast cancer increases with age. Most men diagnosed with the disease are over the age of 60.
Known risk factors
There is convincing evidence that the following factors increase a man’s risk for breast cancer.
A family history of breast cancer increases the risk of breast cancer in men. The greater the number of close relatives (men or women) who have breast cancer, the greater a man’s risk for developing the disease.
BRCA gene mutations are changes to the breast cancer genes. Only a very small number of breast cancers in men are caused by an inherited gene mutation. BRCA2 mutations increase the risk of breast cancer in men more than they increase the risk in women. Mutations in the BRCA1 gene also increase the risk of breast cancer in men, but not as much as the BRCA2 gene mutation. Men who carry these gene mutations may pass them on to their children. Children of men with breast cancer have a higher risk of developing breast cancer.
Klinefelter syndrome is a very rare inherited, or genetic, disorder. Men with Klinefelter syndrome have lower than normal levels of androgens and higher than normal levels of estrogen in their bodies. These changes in hormone levels are linked with a higher risk of developing breast cancer.
Exposure to radiation, especially radiation to the chest, increases the risk of breast cancer in men.
It is important for men to know what is normal for their breasts and to report any changes to their doctor. The most common sign of breast cancer in men is a painless lump, usually near or under the nipple. Other signs and symptoms include:
- discharge or bleeding from the nipple
- crusting of the nipple
- a nipple that suddenly points inward, or becomes inverted
- pain or swelling of the breast
- a lump in the armpit (called the axilla)
- an open sore, or ulcer, on the skin of the breast that doesn’t heal
Later signs and symptoms occur as the cancer grows larger or spreads to other parts of the body, including other organs. Late symptoms of breast cancer in men include:
- weight loss
- bone pain
- cough or shortness of breath
Diagnostic mammography is an x-ray that uses small doses of radiation to make an image of the breast. It is used to follow up on abnormal results of a clinical breast exam. Mammography can also be used to guide the doctor to an abnormal area during a biopsy.
An ultrasound uses high-frequency sound waves to make images of parts of the body. It is used to find out if a breast lump is a solid tumour or a cyst. Doctors may also use an ultrasound to guide them to an abnormal area during a biopsy. If a man has advanced breast cancer, doctors may use an ultrasound to check if the cancer has spread to the liver (called liver metastases).
During a biopsy, the doctor removes tissues or cells from the body so they can be tested in a lab. A report from the pathologist will confirm whether or not cancer cells are present in the sample. A breast biopsy is the only definite way to diagnose breast cancer. Doctors may use the following types of biopsy.
Fine needle aspiration (FNA) uses a very thin needle and syringe to remove a small amount of tissue from a lump. It can help find out if the lump is a cyst or a tumour. It is the most common type of biopsy used to diagnose breast cancer in men because most lumps can be easily reached with the needle. Find out more about fine needle aspiration.
Survival statistics for breast cancer in men
Survival statistics are very general estimates and must be interpreted very carefully. Because these statistics are based on the experience of groups of people, they cannot be used to predict a particular person’s chances of survival. There are many different ways to measure and report cancer survival statistics. Your doctor can explain the statistics for breast cancer in men and what they mean to you. Net survival represents the probability of surviving cancer in the absence of other causes of death. It is used to give an estimate of the percentage of people who will survive their cancer. In Canada, the 5-year net survival for breast cancer in men is 80%. This means that, on average, about 80% of men diagnosed with breast cancer will survive for at least 5 years.
Survival by stage of breast cancer in men is reported as 5-year relative survival. Relative survival looks at how likely people with cancer are to survive after their diagnosis compared to people in the general population who do not have cancer but who share similar characteristics (such as age and sex).