Breast Cancer in Men Explained

Breast cancer in men shares the same basic types as breast cancer in women, though the frequency of each type differs. Understanding the specific type is essential for determining the most effective treatment plan.

The most common type of breast cancer in men is invasive ductal carcinoma, which accounts for approximately 90 percent of all male breast cancer cases. This type begins in the cells lining the milk ducts and then breaks through the duct wall, invading the surrounding breast tissue. From there, it can spread to nearby lymph nodes and other parts of the body.

Invasive lobular carcinoma is rare in men because men have very few lobules — the milk-producing glands at the ends of the ducts. When it does occur, it can be harder to detect on imaging because it does not always form a distinct lump.

Ductal carcinoma in situ (DCIS) is a noninvasive form of breast cancer where abnormal cells are found inside the milk ducts but have not spread beyond them. It is considered the earliest stage of breast cancer and is highly treatable.

Paget’s disease of the nipple is an uncommon form that starts in the milk ducts and spreads to the skin of the nipple and areola. It causes crusting, redness, and flaking of the nipple skin and is often mistaken for eczema or a skin rash. This form is more common in men than in women.

Inflammatory breast cancer is a rare, aggressive form that causes the breast to become red, swollen, and warm to the touch. It does not usually present as a distinct lump and is often diagnosed at a later stage.

Breast cancers are also classified by their receptor status, which guides treatment:

• Hormone receptor-positive (ER+ or PR+): About 90 percent of male breast cancers are estrogen receptor-positive, meaning the cancer cells grow in response to estrogen.
• HER2-positive: About 10 to 15 percent of male breast cancers have excess HER2 protein, which promotes cancer growth.
• Triple-negative: This rare subtype in men lacks receptors for estrogen, progesterone, and HER2 and may be more aggressive.

Because the vast majority of male breast cancers are hormone receptor-positive, hormone therapy is a cornerstone of treatment and is often highly effective.

The symptoms of breast cancer in men are similar to those in women, but men are often less likely to notice or report them early. This can lead to a later diagnosis, when the cancer is more advanced.

The most common symptom is a painless lump or thickening in the breast tissue, usually located directly under the nipple or areola. Because men have significantly less breast tissue than women, even a small lump may be easier to feel. Most male breast lumps are painless, though some may cause mild discomfort.

Nipple changes are another frequent symptom. These can include:

• Nipple discharge, which may be clear, bloody, or yellowish
• Nipple retraction, where the nipple turns inward
• Ulceration or a sore on the nipple that does not heal
• Crusting, scaling, or flaking of the nipple or areola

Skin changes on the chest may include:

• Dimpling or puckering of the skin, sometimes described as looking like an orange peel
• Redness, swelling, or warmth in the breast area
• Thickening of the skin
• A visible change in the size or shape of the breast

Swollen lymph nodes under the arm or around the collarbone may indicate that the cancer has spread to the lymphatic system.

It is important to note that most breast lumps in men are not cancerous. The most common cause of a breast lump in men is gynecomastia, a noncancerous enlargement of breast tissue usually related to hormonal changes. Other benign causes include lipomas (fatty lumps), cysts, and infections.

However, any persistent lump, nipple change, or skin change should be evaluated by a doctor promptly. Because breast cancer in men is rare, many men do not consider it a possibility and may delay seeking medical attention. This delay can allow the cancer to progress to a more advanced stage before it is diagnosed.

Breast cancer in men is caused by genetic mutations that allow cells in the breast tissue to grow and divide uncontrollably. While the exact cause is not always identifiable, several well-established risk factors increase the likelihood of developing the disease.

Genetic mutations play a major role. The strongest known genetic risk factor for male breast cancer is a mutation in the BRCA2 gene. Men with a BRCA2 mutation have a significantly increased risk — approximately 6 to 8 percent of all male breast cancers are linked to BRCA2 mutations. BRCA1 mutations also increase risk, though to a lesser degree than BRCA2. Other genes that can contribute include CHEK2, PALB2, PTEN, and ATM.

Family history is important. Men who have a close female relative (mother, sister, or daughter) with breast cancer have a higher risk of developing breast cancer themselves. A family history of ovarian, pancreatic, or prostate cancer may also be relevant, particularly when BRCA mutations are involved.

Age is a significant factor. The risk of breast cancer in men increases with age, with most cases diagnosed between the ages of 60 and 70. The average age at diagnosis is about 68 to 72.

Hormonal factors are central to many cases. Because approximately 90 percent of male breast cancers are hormone receptor-positive, conditions that increase estrogen levels or decrease androgen levels raise the risk. These include:

• Obesity: Fat tissue converts androgens into estrogen, leading to higher circulating estrogen levels.
• Chronic liver disease or cirrhosis: The liver is responsible for metabolizing and eliminating estrogen. When liver function is impaired, estrogen levels can rise.
• Klinefelter syndrome: A genetic condition where a man is born with an extra X chromosome (XXY). Men with Klinefelter syndrome have lower testosterone levels and higher estrogen levels, giving them a 20 to 50 times greater risk of breast cancer than men without the condition.
• Hormone therapy for prostate cancer: Drugs that lower testosterone or block its effects can alter hormone balance.

Testicular conditions have also been linked to male breast cancer. These include mumps orchitis (inflammation of the testicles caused by the mumps virus), an undescended testicle, and testicular injury or removal. These conditions can affect hormone production and increase risk.

Radiation exposure to the chest area, particularly during childhood or early adulthood, increases the risk of developing breast cancer later in life. This includes radiation therapy for conditions such as Hodgkin lymphoma.

Alcohol consumption, particularly heavy or chronic use, is associated with an increased risk. Alcohol can increase estrogen levels and contribute to liver damage, both of which raise risk.

Race also plays a role. Black men have a higher incidence of breast cancer and a higher mortality rate than White men. The reasons for this disparity are not fully understood but may involve genetic, socioeconomic, and healthcare access factors.

It is important to understand that having one or more risk factors does not mean a man will develop breast cancer. Many men with known risk factors never develop the disease, and some men with no identifiable risk factors are diagnosed.

The diagnosis of breast cancer in men follows a similar process to that in women, but there are some important differences to be aware of.

The first step is a clinical breast exam, during which a doctor will feel the breast tissue, nipple, and surrounding area for any lumps, thickening, or skin changes. The doctor will also check the lymph nodes under the arms and around the collarbone for swelling.

If a suspicious lump or area is found, imaging tests are typically ordered:

• Mammography is the same X-ray technique used for women. It is effective at detecting tumors in male breast tissue, though it can be more uncomfortable due to the smaller amount of breast tissue. Diagnostic mammography (rather than screening) is used when a symptom is already present.
• Ultrasound uses sound waves to create images of the breast tissue. It can help distinguish a solid mass (which may be cancerous) from a fluid-filled cyst (which is usually benign).

The only way to confirm a diagnosis of breast cancer is through a biopsy, where a small sample of tissue is removed from the suspicious area and examined under a microscope. The most common method is a core needle biopsy, which uses a hollow needle to extract tissue. If the lump is difficult to reach or the results are unclear, a surgical biopsy may be performed.

The biopsy sample is tested for hormone receptors (estrogen and progesterone) and HER2 protein. These results are critical because they determine which treatments will be most effective. Approximately 90 percent of male breast cancers are estrogen receptor-positive, which means they respond to hormone therapy.

Once cancer is confirmed, staging tests are done to determine whether the cancer has spread. These may include:

• Sentinel lymph node biopsy: A dye or radioactive tracer is injected to identify the first lymph node that drains fluid from the breast. This node is removed and checked for cancer cells.
• CT scan, MRI, or PET scan of the chest, abdomen, and pelvis to look for spread to other organs.
• Bone scan to check for spread to the bones.
• Blood tests, including a complete blood count and liver function tests.

Genetic testing for BRCA2 and other inherited mutations is recommended for all men diagnosed with breast cancer. The results can have implications not only for treatment decisions but also for cancer screening in the man and his family members.

Staging ranges from 0 (cancer confined to the ducts) to IV (cancer that has spread to distant organs). The stage at diagnosis is the most important factor in determining treatment and prognosis.

Because breast cancer in men is rare, there are no routine population-based screening programs for men at average risk. Prevention focuses on identifying high-risk individuals and taking steps to reduce risk or detect cancer at an early stage.

For men with a known BRCA2 mutation or a strong family history of breast cancer, the following measures may be recommended:

• Regular clinical breast exams starting at age 35 (or earlier based on family history)
• Annual mammography or breast MRI for very high-risk individuals
• Consideration of risk-reducing mastectomy in select cases with very high genetic risk
• Genetic counseling before deciding on any preventive surgery

For men with Klinefelter syndrome, regular breast self-awareness and clinical exams are advised due to the significantly elevated risk.

For the general population, lifestyle measures can help reduce risk:

• Maintain a healthy body weight. Fat tissue produces estrogen, and higher estrogen levels are linked to an increased risk of hormone receptor-positive breast cancer.
• Limit alcohol consumption. Heavy drinking raises estrogen levels and can damage the liver, which normally helps clear excess estrogen from the body.
• Exercise regularly. Physical activity helps regulate hormone levels and supports a healthy immune system.
• Be aware of any changes in the breast or nipple area and report them to a doctor promptly. Early detection is associated with much better outcomes.

Because breast cancer in men is so rare, many men — and even some healthcare providers — may not consider it as a possibility when symptoms arise. The most important preventive measure is awareness. Men should know that they can develop breast cancer and should not hesitate to seek medical evaluation if they notice a lump, nipple discharge, skin change, or any other persistent abnormality in the chest area.

For men who have already been treated for breast cancer, prevention of recurrence is the focus. This includes completing the full course of recommended treatments, attending regular follow-up appointments, and making healthy lifestyle choices.

The overall outlook for breast cancer in men has improved significantly over the past several decades, largely due to advances in treatment, particularly hormone therapy.

The five-year relative survival rate for all stages combined is approximately 84 percent, which is similar to the survival rate for breast cancer in women when compared stage for stage. This means that a man diagnosed with breast cancer is about 84 percent as likely as a man without breast cancer to be alive five years after diagnosis.

Survival rates vary significantly by stage at diagnosis:

• Stage I (cancer confined to the breast): approximately 100 percent five-year survival
• Stage II: approximately 91 percent
• Stage III (spread to nearby lymph nodes): approximately 72 percent
• Stage IV (distant metastasis): approximately 20 to 25 percent

One of the biggest challenges with male breast cancer is that it is often diagnosed at a later stage than breast cancer in women. This is due to a combination of factors: lack of awareness among men and healthcare providers, the absence of routine screening, and a tendency for men to delay seeking medical attention for breast symptoms.

When diagnosed at the same stage and with similar tumor characteristics, the prognosis for men is generally comparable to that for women. Age, overall health, tumor grade, receptor status, and response to treatment also influence the outlook.

Approximately 90 percent of male breast cancers are estrogen receptor-positive, which means they can be treated with hormone therapy. This is a significant advantage, as hormone therapy is often very effective in men and can reduce the risk of recurrence.

After treatment, lifelong follow-up is essential. This typically includes regular physical exams, mammograms of the affected side, and monitoring for any signs of recurrence or new cancers. Men who have had breast cancer also have an increased risk of developing a second breast cancer in the unaffected breast, as well as other cancers linked to BRCA mutations, such as prostate and pancreatic cancer.

The risk of recurrence is highest within the first five years after treatment. After that, the risk decreases but does not disappear entirely. Adherence to recommended follow-up and ongoing communication with your healthcare team are essential for long-term health.

Treatment for breast cancer in men follows many of the same principles as treatment for women, but there are important differences. A multidisciplinary team — including a surgeon, medical oncologist, radiation oncologist, and genetic counselor — typically works together to develop a personalized treatment plan.

Surgery is the primary treatment for most men with breast cancer. The standard procedure is a modified radical mastectomy, which involves removing the entire breast tissue, the nipple and areola, and often the underarm lymph nodes on the affected side. Breast-conserving surgery (lumpectomy) is less commonly performed in men because they have so little breast tissue. Sentinel lymph node biopsy is used to determine whether cancer has spread to the lymph nodes, while axillary lymph node dissection is performed if cancer is found in the sentinel nodes.

Radiation therapy uses high-energy beams to destroy any remaining cancer cells after surgery. It is typically recommended after mastectomy if the tumor was large, if the surgical margins were positive (cancer cells close to the edge of the removed tissue), or if cancer was found in multiple lymph nodes. Radiation is usually given daily for several weeks.

Chemotherapy uses drugs to kill cancer cells throughout the body. It may be given after surgery (adjuvant chemotherapy) to lower the risk of recurrence, or before surgery (neoadjuvant chemotherapy) to shrink a large tumor and make it easier to remove. Chemotherapy is recommended when there is a higher risk of the cancer returning, such as with larger tumors, lymph node involvement, or aggressive tumor characteristics.

Hormone therapy is a cornerstone of treatment for male breast cancer because approximately 90 percent of cases are hormone receptor-positive. Tamoxifen is the first-line and most well-studied hormone therapy for men. It works by blocking estrogen from binding to cancer cells. Tamoxifen is typically taken as a daily pill for five to ten years and has been shown to significantly reduce the risk of recurrence. Aromatase inhibitors, which lower estrogen levels in the body, are used less frequently in men because they are less effective without also suppressing testicular estrogen production. When aromatase inhibitors are used, they are often combined with LHRH agonists to suppress testosterone production in the testicles.

Targeted therapy is used for cancers that have specific molecular characteristics. For HER2-positive breast cancer, drugs such as trastuzumab (Herceptin), pertuzumab (Perjeta), and antibody-drug conjugates like trastuzumab emtansine (Kadcyla) or trastuzumab deruxtecan (Enhertu) can be highly effective. For advanced ER-positive, HER2-negative breast cancer, CDK4/6 inhibitors (palbociclib, ribociclib, abemaciclib) are often combined with hormone therapy. Antibody-drug conjugates such as sacituzumab govitecan (Trodelvy) and datopotamab deruxtecan (Datroway) are newer options for specific subtypes.

Immunotherapy with checkpoint inhibitors may be an option for certain advanced breast cancers, particularly those that are triple-negative and express PD-L1.

It is important to note that men with breast cancer should not take testosterone replacement therapy. Testosterone can be converted into estrogen in the body and may fuel the growth of hormone receptor-positive breast cancer.

Clinical trials may offer access to new treatments for men with advanced or treatment-resistant breast cancer.

After treatment, lifelong follow-up care is essential. This includes regular physical exams, mammography, and monitoring for long-term side effects of treatment. Men who have been treated for breast cancer also need to be screened for other cancers associated with BRCA mutations, such as prostate and pancreatic cancer.

There is no specific diet designed exclusively for male breast cancer, but good nutrition plays an important role in supporting treatment, recovery, and overall health.

A balanced diet rich in fruits, vegetables, whole grains, and lean proteins provides the vitamins, minerals, and antioxidants your body needs to maintain strength during treatment and support healing after surgery.

Maintaining a healthy weight is particularly important for men with breast cancer because fat tissue produces estrogen. Since most male breast cancers are hormone receptor-positive, excess body weight can lead to higher estrogen levels, which may increase the risk of recurrence. Losing weight if you are overweight and maintaining a healthy weight after treatment is one of the most important dietary goals.

Foods that may be especially beneficial include:

• Fruits and vegetables: Especially colorful varieties like berries, leafy greens, broccoli, carrots, and bell peppers, which are rich in antioxidants that help protect cells from damage.
• Whole grains: Oats, quinoa, brown rice, whole wheat bread, and barley provide fiber and nutrients that support overall health.
• Lean proteins: Chicken, fish, eggs, beans, lentils, and tofu help the body repair tissues and maintain muscle mass during treatment.
• Healthy fats: Olive oil, avocados, nuts, seeds, and fatty fish such as salmon and mackerel provide omega-3 fatty acids with anti-inflammatory properties.

Foods to limit or avoid:

• Red and processed meats have been linked to an increased risk of several cancers and may contribute to inflammation.
• Alcohol can increase estrogen levels and may interfere with treatment. It also puts additional strain on the liver, which is responsible for processing chemotherapy drugs and metabolizing hormones.
• Sugary drinks, refined carbohydrates, and highly processed foods provide empty calories and can contribute to weight gain.

During chemotherapy or radiation, side effects such as nausea, loss of appetite, taste changes, and fatigue can make eating difficult. Practical strategies include:

• Eating small, frequent meals throughout the day rather than three large ones
• Choosing nutrient-dense foods that provide protein and calories in smaller portions
• Staying well hydrated with water, herbal tea, and clear broths
• Avoiding raw or undercooked foods if the immune system is weakened
• Working with a registered dietitian who specializes in cancer care

After treatment ends, continuing a healthy, balanced diet and staying physically active can help reduce the risk of recurrence and improve long-term health outcomes.

Breast cancer in men is a rare disease, accounting for less than one percent of all breast cancer cases, but it is a serious condition that requires prompt attention. The most common type is invasive ductal carcinoma, and approximately 90 percent of male breast cancers are hormone receptor-positive, meaning they grow in response to estrogen or progesterone. A painless lump beneath the nipple or areola is the most frequent symptom, though nipple discharge, retraction, skin changes, or swelling in the underarm lymph nodes can also occur. Because men are often unaware that they can develop breast cancer, they may delay seeking evaluation, and the disease is frequently diagnosed at a more advanced stage than in women. Key risk factors include advancing age, BRCA2 gene mutations (the strongest known genetic risk factor), a strong family history of breast or ovarian cancer, Klinefelter syndrome, obesity, chronic liver disease, and conditions that alter estrogen levels. Diagnosis involves clinical examination, imaging such as mammography and ultrasound, biopsy, and hormone receptor testing. Treatment typically begins with mastectomy, followed by radiation, chemotherapy, hormone therapy with tamoxifen, and targeted therapy when appropriate. With proper treatment, the overall five-year survival rate is approximately 84 percent, and when caught early, the prognosis is excellent. Men diagnosed with breast cancer should also undergo genetic testing for BRCA mutations, which has important implications for their own health and for cancer screening in their family members.