Both men and women have breast tissue

In men, most breast tissue is located behind the nipple. Women have a lot more breast tissue than men – and a much higher rate of breast cancer. Cancers can, however, occur in male breast tissue. Breast cancer is uncommon in men. The average age at diagnosis is 71 years old.

As our population ages, it is therefore increasingly important to provide information and support to affected men and their families. Since there are relatively few cases of breast cancer in men compared to women, there is less information and research focused specifically on male breast cancer. As a result, treatment decisions for male breast cancer are often based on studies of breast cancer in women.

Risk factors

Several factors are known to increase the risk that a man will develop breast cancer. But it’s important to know that many men who develop breast cancer do not have any of these risk factors.

Factors that can increase a man’s breast cancer risk include:

Growing older:

The risk of male breast cancer increases as you age. The average age of men diagnosed with breast cancer, about 67. But breast cancer can occur in young men, too.

Family history of breast cancer:

A man’s risk for breast cancer is higher if any of his close relatives have had breast cancer, and especially if any male relatives have had the disease.

Genetic mutations:

Men who inherit certain genetic mutations from their mothers or fathers have a higher risk of developing breast cancer. A man who inherits a BRCA1 mutation has about a 1% risk of developing breast cancer in his lifetime, compared to a risk of 0.1% (about one in 1,000) for the average man. A man who inherits a BRCA2 mutation has a 7% to 8% risk.

Mutations in the ATM, CHEK2, PALB2, and other genes are also linked to breast cancer in men, but more research is needed to understand those risks.

High estrogen levels:

You may think of testosterone as a male hormone and estrogen as a female hormone. The truth is, both men and women have different levels of testosterone and estrogen in their bodies. Men have less estrogen than women, but all men have some estrogen in their bodies.

Higher levels of estrogen can increase the risk of male breast cancer. Men (and people assigned male at birth) can have high estrogen levels as a result of:

– Hormone therapy for prostate cancer (androgen suppression therapy).
– Hormone therapy taken by transgender women (as part of male-to-female transition; also called feminizing hormone therapy or gender affirming hormone replacement therapy).
– Being overweight or obese.
– Being a heavy drinker or having liver disease (like cirrhosis), both of which can limit the liver’s ability to balance hormone levels in the blood.
– Having an undescended testicle.
– Surgery to remove one or both testicles (orchiectomy).
– Swelling or injury of the testicles.

Klinefelter syndrome:

Men usually have one X and one Y chromosome in their cells. But men born with Klinefelter syndrome — a rare genetic condition that happens when a male is born with more than one X chromosome in their cells — may increase their risk of breast cancer.

Kinefelter syndrome may cause the testicles to develop abnormally. This can result in lower levels of androgens (usually higher in males) and higher levels of estrogen.
Men with Klinefelter’s syndrome may have an increased risk of developing gynecomastia (breast tissue growth that is not cancer) and male breast cancer.

Radiation exposure:

If a man has received radiation therapy to the chest, such as for the treatment of Hodgkin lymphoma, he has an increased risk of developing breast cancer.

The symptoms of breast cancer in men

The most common symptoms of breast cancer in men include:

– Breast lump or swelling.
– Nipple that turns inward (inversion).
– Fluid leaking from the nipple discharge, that may be bloody.
– A pain or pulling sensation in the breast.
– Skin or nipple changes such as dimpling, puckering, redness, or scaling.

These changes can also can be signs of less serious conditions that are not cancer. Some benign (non-cancerous) breast conditions in men are:

Gynecomastia:

Gynecomastia is an increase in the amount of breast tissue in males. It can involve swelling or overall enlargement of one or both breasts. Often, the first symptom is a lump of fatty tissue under the nipple that may be tender or sore.

Gynecomastia can occur in male babies, boys going through puberty, or adult men. It is typically caused by an imbalance of the hormones estrogen and testosterone. This imbalance can be due to normal changes in hormone levels or to other factors such as taking certain medicines, heavy alcohol use, marijuana use, weight gain, liver disease, or kidney disease.

Gynecomastia is the most common non-cancerous breast condition in males. If a man has enlargement of both breasts (not just on one side) that is often a sign that he doesn’t have male breast cancer and is more likely to have gynecomastia.

Benign (non-cancerous) breast lumps:

Men can develop other types of abnormal lumps or masses of tissue in the breast that are not cancer and do not spread outside the breast. Some examples are lipomas (lumps of fatty tissue), cysts (fluid-filled sacs), hematomas (accumulations of blood), and fat necrosis (firm scar tissue).

Treatment

Surgery:

The main treatment for male breast cancer is surgery. The most common surgery is a modified radical mastectomy. This means removing the breast, many of the lymph nodes under the arm, the lining over the chest muscles, and sometimes part of the chest wall muscles.

Radiation therapy:

Radiation therapy sends high levels of radiation directly to the cancer cells. Radiation after surgery can kill cancer cells that may not be seen during surgery. Radiation may also be done before surgery to shrink the tumor. It may be done along with chemotherapy. Or it may be used as a palliative treatment. This is a therapy that relieves symptoms, such as pain, but doesn’t treat the disease.

Radiation therapy is usually external beam radiation. This is also called external beam therapy. The machine is controlled by a radiation therapist. Since radiation is used to kill cancer cells and to shrink tumors, special shields may be used to protect the tissue around the treatment area. The treatments are painless and usually last a few minutes.

Chemotherapy:

Chemotherapy is the use of anticancer medicines to kill cancer cells. In most cases, chemotherapy works by interfering with the cancer cell’s ability to grow or reproduce. Different groups of medicines work in different ways to fight cancer cells. The cancer doctor (oncologist) will recommend a treatment plan for each person.

Hormone therapy:

In some cases, hormones can kill cancer cells, slow the growth of cancer cells, or stop cancer cells from growing. Hormone therapy as a cancer treatment involves taking substances to interfere with the activity of hormones or to stop the production of hormones. Before you begin hormone therapy, your doctor will do a hormone receptor test.

This lab test is done on a small piece of the cancer tissue to see if estrogen and progesterone receptors are present. A hormone receptor test can help to predict whether cancer cells are sensitive to hormones. If so, hormone therapy may be given to help keep the hormone away from the cancer cells.