Male Breast Cancer

A mass or lump under the skin of the breast is a common sign of possible breast cancer. Most of male breast cancers are located underneath a nipple of one breast, although a lump could be elsewhere in the breast area.  

Other symptoms include: 

• A breast nipple that turns or points inward
• Skin changes in the breast area, such as swelling or redness
• Ulcers of the skin in the breast area.

Swollen lymph nodes underneath one arm may also indicate cancer, but lymph nodes can swell for a variety of reasons.

The cause of breast cancer is the same in men as in women. It occurs when cells in breast tissue mutate and grow out of control, forming a tumor (or mass of tissue). As it advances, breast cancer can spread to other areas of the breast or to other parts of the body.

Most breast cancers that develop in men, as well as women, are driven by the hormone estrogen. Men tend to have much less estrogen than women, but certain conditions can raise estrogen levels in men: 

• Obesity: Fat cells in the body contain an enzyme called aromatase, which can convert other hormones in the body into a form of estrogen called estradiol. Thus, obesity can raise the amount of estrogen in a man’s body.
• Severe liver disease: When the liver does not work well, female estrogen levels tend to increase and male hormones tend to decrease.
• Klinefelter syndrome: Men with this rare genetic condition are born with an extra X chromosome, which causes their bodies to produce higher amounts of estrogen and lower amounts of androgens, which are male sex hormones.
• Taking exogenous estrogen: Transgender women who take feminizing hormone therapy have a higher risk of developing breast cancer than cisgender men, but not as high as the general female population.

A number of other risk factors influence a man’s risk of developing breast cancer: 

• Getting older: Most male breast cancers occur after age 50, according to the Centers for Disease Control and Prevention.
• A family history of breast cancer: If a family member (female or man) had breast cancer, a man’s risk rises.
  • Inherited mutations linked to breast cancer, including BRCA1 and BRCA2, also increase a man’s risk.
• Gynecomastia: Men with this condition have a greater amount of breast tissue than normal. Because these men have more breast tissue, they have more breast cells that could potentially mutate and become cancerous.
• Race/ethnicity: One study found that Black men had a 52% higher incidence of breast cancer than white men.
• Radiation treatment: Men who have had radiation treatment to the chest have a higher risk of breast cancer.

Approximately 20% of men who develop breast cancer have a family member — female or male — who also had the disease. Men with a family history of the disease should talk to their physician about their risk and whether they may benefit from genetic testing and counseling. 

If a family member is found to carry genetic mutations, such as BRCA1 or BRCA2, then men should definitely seek genetic testing and counseling. Genetic mutations, such as BRCA 1 and BRCA 2, can raise a man’s risk for prostate and pancreatic cancers as well as breast cancers. 

UChicago Medicine’s Comprehensive Cancer Risk & Prevention Clinic can help men determine their risk for all types of cancer. Genetic counselors at the clinic also provide patients with a personalized plan for when to get screenings and exams, as well as how to lower their risk for cancers.

Currently , recommendations from the National Comprehensive Cancer Network only recommend yearly clinical breast exams by a doctor for men who test positive for the BRCA2 or BRCA1 mutations, beginning at age 35. These men should also learn how to perform breast self-exams.   

However, if you have a high risk for breast cancer because of family history or a medical condition, you may benefit from self-exams and yearly clinical breast exams. Talk to your doctor for guidance. 

Mammograms and other diagnostic tests are generally only performed on men who are suspected of having breast cancer.

At UChicago Medicine, we recommend that all men who are diagnosed with breast cancer obtain genetic tests to learn if they carry genetic mutations. 

• If the patient tests positive for an inherited mutation, then his family members should also seek genetic testing to determine if they carry the mutation.
• If the patient has a negative genetic test, then his family members may still have a slight increased hereditary risk for breast cancer. Genetic tests cannot yet identify all the genetic mutations that raise disease risk.

Oncologists divide breast cancers into three groups based on the following questions: 

1. Are hormone receptors — estrogen and progesterone — present? If so, the cancer is known as a hormone-driven cancer.
2. Is a protein called HER2 present in the cancer cells? If so, the cancer is known as a HER2 positive cancer. The protein HER2 encourages the growth of cancer cells.
3. Are the answers to the two previous questions “no?” Then the cancer is called triple-negative breast cancer. 

Based on what is currently known, men seem to develop the same types of breast cancer as women do. The majority of breast cancers in both men and women are hormone driven. About 15% to 20% are HER2, and about 10% to 15% are triple-negative cancers. 

However, the amount of research on male breast cancer is small. As more research is conducted, scientists may identify subtle differences between the types of breast cancer that men and women tend to develop.  

Knowing the type of breast cancer a patient has is critical to determining the best treatment options. For instance, drug treatments for HER2 cancers are different than for hormone-driven cancers.

If breast cancer is suspected, a man will likely undergo imaging tests, such as a mammogram, ultrasound, and/or an MRI. 

Ultimately, a biopsy must be performed to rule out or confirm that a patient has breast cancer. A biopsy involves removing a sample of breast cells from the area of the breast where cancer is suspected. This can often be done with a needle. A pathologist can then examine and run tests on the cells to make a formal diagnosis.

If a man’s treatment plan includes surgery, then the operation typically involves removal of the entire breast that has a tumor. This surgery, which is called a mastectomy, is necessary because men have such little breast tissue. It can be difficult to only remove the tumor and preserve the anatomy and appearance of the male breast.  

During the mastectomy, the lymph nodes under the arm near the cancerous breast may also be removed if they are found or suspected to contain cancer. 

Plastic surgeons at UChicago Medicine can talk with male patients about their options for reconstructive surgery, which may include nipple implants and reconstruction.

Patients may need chemotherapy, either before surgery to shrink the tumor so it can be removed with a less extensive operation or after surgery to kill cancer cells left behind after the operation. 

If a man has hormone-driven breast cancer, then he is typically prescribed antiestrogen therapy, typically the drug tamoxifen, for five or more years. The drug, which blocks estrogen in the body, helps prevent breast cancer recurrence.  

In recent years, new and exciting drug treatments for breast cancers, including late-stage cancers, have come available. Men with HER2 cancers now benefit from drugs that specifically target HER2 positive cancers. Other targeted drugs, known as PARP inhibitors, are being used to treat cancers with BRCA1 and BRCA2 mutations. In addition, immunotherapy can be used to stimulate the immune system to fight triple-negative breast cancers. Plus, new antibody drugs act like smart bombs, delivering chemotherapy directly to cells that carry certain proteins or other substances.

Because male breast cancer is rare, it is very difficult to conduct a major study of the disease at a single medical center. Researchers need to conduct studies across multiple institutions to recruit enough male breast cancer patients to participate.

Our physician researchers are investigating a number of novel treatments for breast cancer and plan to enroll both men and women with the disease in the studies.

Our patients and their families have access to our dedicated supportive oncology program, which provides a range of services, including mental health counseling, social work services and more.

In addition, patients have access to a wide range of other supportive staff and services, including: 

• Nurse practitioners who will help men navigate their cancer treatment 
• Nutritionists to help maintain a healthy diet
• Pain control experts
• Physical and occupational therapists who can help patients with physical side effects of cancer treatment
• Physician specialists who can help address medical concerns related to treatment, such as cardio-oncologists who can consult on heart problems caused by treatment.