Breast Cancer in Men

Though rare, breast cancer does occur in men because they have breast tissue that can become cancerous, just like in women. Understanding the signs, knowing your risk factors, and seeking prompt medical attention for any unusual changes can make a crucial difference in outcomes.

Table of contents

• What is breast cancer in men?
• The male breast
• How common is it?
• Types of male breast cancer
• Signs and symptoms
• Risk factors
• What causes male breast cancer?
• How is it diagnosed?
• Treatment options
• Outlook and survival
• Emotional and practical support

What is breast cancer in men?

Male breast cancer is a disease in which malignant (cancer) cells form in the breast tissue of men^[1]. While breast cancer is typically thought of as a condition that happens in women, everyone is born with some breast tissue, so anyone can get breast cancer^[1].

Male breast cancer is a rare form of cancer that grows in the breast tissue in the chest. When most people think of breast cancer, they typically think of women, but males also have breast tissue that can become cancerous^[3]. Because it’s so rare, it can be easy to dismiss a lump in the breast as no big deal if you’re male. But it’s important to get all suspicious lumps checked by a healthcare provider^[3].

The male breast

Boys and girls begin life with similar breast tissue. However, men don’t have the same complex breast growth and development as women^[5]. At puberty, high testosterone levels and low estrogen levels stop breast development in men. Men have some milk ducts, but they remain undeveloped. Lobules (glands that produce milk) are most often absent. However, breast problems, including breast cancer, can occur in men^[5].

The male breast contains a nipple and areola on the outside. On the inside, there are lymph nodes, fatty tissue, ducts, and other parts^[2]. Though male breasts are less developed, all adults have breast tissue^[15].

How common is it?

Male breast cancer is extremely rare. Less than 1% of all breast cancers occur in men^[5]. About 1 out of every 100 breast cancer diagnoses affects males^[3]. In the United States, approximately 2,800 males receive this diagnosis each year, and about 510 men will die from the disease^[6].

The lifetime risk of getting breast cancer is about 1 in 1,000 for men in the U.S., compared to 1 in 8 for women in the U.S.^[5]. From 2018 to 2022, the breast cancer incidence rate in men increased slightly (by less than 1% per year)^[5].

Breast cancer may occur in men at any age, but it usually occurs in men between 60 and 70 years of age^[7]. Most people diagnosed are in their 60s^[3].

Types of male breast cancer

Cancer is most likely to form in the breast ducts. Ducts are tubes that connect glands called lobules to the nipple^[3]. The most common kinds of breast cancer in men are^[2]:

• Invasive ductal carcinoma. The cancer cells begin in the ducts and then grow outside the ducts into other parts of the breast tissue. Invasive cancer cells can also spread, or metastasize, to other parts of the body. Up to 9 out of 10 male breast cancers are invasive ductal carcinoma^[3].
• Ductal carcinoma in situ (DCIS). This is a breast disease that may lead to invasive breast cancer. The cancer cells are only in the lining of the ducts and have not spread to other tissues in the breast. With this type, the cancer starts in the breast ducts but doesn’t spread beyond them^[2][3].

Other, less common types include^[7]:

• Inflammatory breast cancer. A type of cancer in which the breast looks red and swollen and feels warm.
• Paget disease of the nipple. A tumor that has grown from ducts beneath the nipple onto the surface of the nipple.
• Invasive lobular carcinoma. With this type, cancer forms in the lobules of the breast. This type is uncommon because males have few, if any, lobules^[3].

Most male breast cancers have receptors on them that cause them to grow in response to specific hormones. Think of a receptor as a lock that fits a specific key (hormone). When the hormone attaches to the receptor, cancer cells divide and multiply. Most male breast cancers have receptors that cause cancer cells to grow in response to progesterone and estrogen^[3]. The most common form of breast cancer in males is estrogen receptor-positive (ER+) invasive ductal carcinoma^[3].

Signs and symptoms

The first sign of male breast cancer is often a firm, painless lump in one of the breasts, usually behind a nipple^[1][3]. The most common symptoms of breast cancer in men are^[2]:

• A lump or swelling in the breast
• A lump in the armpit
• Redness or flaky skin in the breast
• Irritation or dimpling of breast skin
• Skin on the chest that looks dimpled or pitted, like the skin of an orange^[3]
• Red, flaky, or scaly skin on the chest or near the nipple^[3]
• Nipple discharge or bleeding from the nipple
• Clear or bloody nipple discharge^[3]
• Pulling in of the nipple or pain in the nipple area
• An inverted nipple (a nipple that’s sunken inward)^[3]
• Pain or tenderness in the chest or underarm^[3]

These symptoms can happen with other conditions that are not cancer. If you have any symptoms or changes, see your doctor right away^[2]. Men with breast cancer usually have lumps that can be felt^[7].

Risk factors

Several factors can increase a man’s chance of getting breast cancer^[2]:

Age. The risk for breast cancer increases with age. Most breast cancers are found after age 50^[2]. Most people diagnosed are in their 60s^[3].

Genetic mutations. Inherited changes (mutations) in certain genes, such as BRCA1 and BRCA2, increase breast cancer risk^[2]. Although it is rare for a male to have a BRCA mutation, those with a BRCA2 carrier mutation have a 6% increased risk, and BRCA1 has a 4% risk of developing the disease^[10]. At age 70 years, men have an estimated cumulative breast cancer risk of 1.2% if they have BRCA1 pathogenic variants and 6.8% if they have BRCA2 pathogenic variants^[12].

Less common mutations occur in Cowden syndrome (PTEN gene), Li-Fraumeni syndrome (TP53), and Lynch syndrome (MMR gene)^[3][12].

Family history of breast cancer. You’re at greater risk if you have a parent, sibling, or child with breast or ovarian cancer. This is because certain breast cancer genes run in families^[3]. A man’s risk for breast cancer is higher if a close family member has had breast cancer^[2].

Radiation therapy treatment. Men who had radiation therapy to the breast or chest have a higher risk of getting breast cancer^[2].

Hormone therapy treatment. Drugs containing estrogen (a hormone that helps develop and maintain female sex characteristics), which were used to treat prostate cancer in the past, increase men’s breast cancer risk^[2].

High estrogen levels. Conditions that raise estrogen include cirrhosis (scarring) of the liver, obesity, and a genetic disorder called Klinefelter syndrome^[3]. Klinefelter syndrome is a rare genetic condition in which a male has an extra X chromosome. This can lead to the body making higher levels of estrogen and lower levels of androgens (hormones that help develop and maintain male sex characteristics). Certain conditions that affect the testicles can increase breast cancer risk^[2].

Liver disease. Cirrhosis of the liver can lower androgen levels and raise estrogen levels in men, increasing the risk of breast cancer^[2].

Overweight and obesity. Older men who are overweight or have obesity have a higher risk of getting breast cancer than men at a healthy weight^[2].

What causes male breast cancer?

Male breast cancer happens when the DNA inside breast cells changes, or mutates. The mutated cells start multiplying rapidly and don’t die. Eventually, the cancer cells form masses called tumors. Parts of the tumor may break off and spread to other body parts through the lymphatic system or bloodstream. Cancer that’s spread is called metastatic cancer^[3].

Scientists continue to research what causes healthy cells to transform into cancer cells in the first place^[3]. Hereditary breast cancer makes up about 5% to 10% of all breast cancer^[7].

How is it diagnosed?

Your doctor may refer you to a specialist or order tests to check for breast cancer or other health problems^[11]. Tests and procedures to diagnose male breast cancer might include^[11]:

Clinical breast exam. During this exam, a health care professional feels the breasts and surrounding areas for lumps or other changes. This exam helps the health professional understand how large the lumps are, how they feel, and how close they are to skin and muscles^[11].

Imaging tests. Imaging tests can create pictures of breast tissue to look for signs of cancer. Tests may include a breast X-ray, called a mammogram, an ultrasound, or an MRI scan^[11]. The American College of Radiology recommends ultrasonography as the first imaging modality in men younger than 25 years because breast cancer is highly unlikely. Mammography is performed if ultrasonography findings are suspicious. For men aged 25 years or older, or those who have a highly concerning physical examination, mammography is recommended as the initial test^[12].

Biopsy. To determine whether you have cancer, you might have a procedure to remove a sample of cells for testing in a lab. This procedure is called a biopsy. To get the sample, a health care professional puts a needle through the skin on your chest. The health professional guides the needle using a mammogram or another imaging test^[11]. In the lab, specialists examine the cells under a microscope to see if they’re cancer^[11].

Other tests can tell whether your cancer cells have hormone receptors or certain DNA changes. If the presence of tumor is confirmed, estrogen receptor, progesterone receptor, and HER2 (human epidermal growth factor type 2) expression/amplification should be evaluated^[12]. The test results help your health care team create a treatment plan^[11].

Staging the cancer. After confirming a diagnosis of breast cancer, your health care team works to find the extent of your cancer. This is called the cancer’s stage. Your health care team uses your cancer’s stage to understand your prognosis and to make a treatment plan. Male breast cancer staging often involves imaging tests. The images can tell your health care team about your cancer’s size and whether it has spread. Tests may include bone scan, CT scan, or positron emission tomography (PET) scan^[11].

Treatment options

Male breast cancer is often treated in the same way as breast cancer in women^[15]. Treatment for male breast cancer typically involves surgery to remove the breast tissue. Other treatments, such as chemotherapy and radiation therapy, may be recommended as well^[1]. A combination of treatments is usually used^[15].

Surgery. Surgery is usually the main treatment for breast cancer^[14]. Surgery can include^[14]:

• Removing the whole breast and nipple (mastectomy) – this is the most common surgery for breast cancer in men and usually involves removing lymph nodes in the armpit (these are small glands that are part of the body’s immune system)
• Removing just the cancer and some breast tissue around it (lumpectomy) – this may mean the nipple does not need to be removed

If you’ve had a nipple removed, you may choose to have the surgeon make a new nipple. They may be able to do this using skin from another part of your body, or by tattooing a new nipple. You will need to wait a few months after the mastectomy. You can also get stick-on nipples^[14].

Radiotherapy. Radiotherapy uses radiation to kill cancer cells. You may have radiotherapy for breast cancer after surgery to lower the chance of the cancer coming back, or if you have secondary breast cancer^[14].

Chemotherapy. Chemotherapy uses medicines to kill cancer cells. You may have chemotherapy for breast cancer before surgery to help make the cancer smaller, after surgery to lower the chance of the cancer coming back, or if you have secondary breast cancer^[14].

Hormone therapy. Some breast cancers are affected by different hormones in the body, which can make them grow faster. Hormone therapy uses medicines to either lower the amount of certain hormones in the body or block certain hormones from getting to breast cancer cells. Hormone therapy may be used before surgery to help make the cancer smaller, after surgery to lower the chance of the cancer coming back, or if you have secondary breast cancer^[14].

Targeted medicines. Targeted medicines kill cancer cells. Targeted medicines may be used to lower the chance of the cancer coming back or if you have secondary breast cancer^[14].

Outlook and survival

Survival for men with breast cancer is similar to survival for women with breast cancer^[7]. Survival rates for men are about the same as for women with the same stage of breast cancer at the time of diagnosis^[5].

However, men are often diagnosed at a later stage of breast cancer than women^[5]. One reason could be that men may be less likely than women to report signs and symptoms. This can lead to delays in diagnosis^[5]. Because of delays in diagnosis, breast cancer in men is more likely to present at an advanced stage^[12].

Breast cancer in men is often diagnosed at a later stage because screening with mammography is not done like it is for women. But breast cancer survival by stage in men is similar to survival by stage in women^[15].

Emotional and practical support

If you’re a man with breast cancer, you may feel a variety of physical and emotional reactions to having cancer and going through treatment. No matter what emotions arise, coping strategies can help^[16].

First, it’s important to have all the information you need to know about your cancer. Ask your healthcare provider questions about your cancer, what treatment will be like, and what the side effects may be. You can also ask your healthcare team if they have advice on how to cope^[16].

Cancer and its treatment can cause physical side effects that can be hard to handle at times. Common physical side effects include extreme tiredness (fatigue), pain, nausea or vomiting, hair loss, changes in weight and appetite, skin rashes or irritation, scars and body changes from surgery, and changes in body image or how you view yourself^[16].

Men who have been treated for breast cancer are encouraged to attend follow-up visits on a schedule determined by their doctors. Mammograms or ultrasounds are typically scheduled every 6 to 12 months after treatment. Your doctor may also recommend that you perform a monthly breast self-exam to help detect a possible recurrence early^[20].

Neuropathy treatment. Neuropathy, or nerve damage, is a common side effect of some chemotherapy drugs used to treat breast cancer. It may lead to numbness, tingling, pain, and weakness in the hands, feet, arms, legs, or other parts of the body. Doctors can prescribe medication to help ease the discomfort caused by neuropathy. They may also recommend physical therapy to prevent the condition from interfering with your balance and strength^[20].

Lymphedema management. Surgery for breast cancer often involves removing lymph nodes, which may damage lymph vessels in the breast and underarm. These vessels carry lymph fluid, which contains bacteria and waste products, away from the body’s organs and tissues. Damage to these vessels can cause lymph fluid to build up, leading to swelling and arm discomfort—a condition known as lymphedema. Doctors and physical therapists can show you how to prevent lymphedema after surgery. They may recommend, for instance, wearing wraps around your arms to compress them. Early treatment is the key to managing lymphedema^[20].

Family and friends are very important for emotional support^[21]. Supportive care specialists can provide therapy for any ongoing cancer-related or treatment-related side effects^[20].