Breast cancer in men

Male breast cancer (MBC) is rare—only about 2,600 new cases will develop in a year. However, anyone with breast tissue—including men—can get breast cancer. Like in almost all parts of the body, cells in that tissue can grow out of control and form a tumor.

Though men make up a small portion of the people who have breast cancer—just less than 1 percent—they’re also often diagnosed at a later stage, which can affect the outcome.

How breast cancer develops in men

Researchers are still working to fully understand breast cancer in men, but they believe the body’s sex hormone levels may play a role, as they do in female breast cancer.

Moreover, additional research is needed to determine the differences between male and female breast cancers. Though they are often treated the same, research is putting a spotlight on differences, including the genetic variations that affect men. This may suggest differences in the biology of breast cancer for men when compared to women.

Like women’s breast tissue, men’s breast tissue has ducts, but has few or no lobules.

Most breast cancer starts in the milk ducts or in the glands, and men have these, even though they’re typically not functional. Other types of breast cancers that start in other breast cells are less common.

Types of breast cancer in men

Breast cancer types are separated into two main groups: invasive or in situ (non-invasive). All kinds of breast cancer fall under one of these categories.

• In situ (non-invasive): When breast cancer is not invasive, it’s most likely ductal carcinoma in situ (DCIS), a non-invasive type of breast cancer that starts in a duct and has not yet spread anywhere else.
• Invasive: Invasive breast cancer refers to any breast cancer that spreads from the original site and “invades” other areas, like nearby breast tissue, lymph nodes or anywhere else in the body.

About 80 percent of all male breast cancers are what’s called invasive ductal carcinoma (IDC). IDC is a cancer that starts in a duct and grows into other parts of the breast.

Men can have several different types of breast cancer. While still rare, the most common types include:

• Ductal carcinoma in situ (cancerous or precancerous cells that have not spread)
• Invasive (infiltrating) ductal carcinoma (cancer starts in a duct and spreads, forming a tumor)
• Inflammatory breast cancer (cancer spreads through tissue layers in the breast, but does not form a lump)
• Paget’s disease of the nipple (cancer starts in a duct and spreads to the nipple and sometimes areola)
• Invasive lobular carcinoma (another type of breast cancer seen in women that is rare in men)
• Other subtypes of carcinomas in the male breast are possible, but extremely rare.

Male breast cancer symptoms

Male breast cancer typically includes a lump that can be felt to the touch. It may feel like a thickening under your skin. Typically, it’s painless.

There are a lot of other possible breast cancer symptoms that might appear in addition to or instead of a lump. You might notice:

• Dimpled or puckered skin
• Dimpling that looks like the skin of an orange
• Redness or scaling on your nipple or skin
• Your nipple has turned inward
• Nipple discharge
• A lump or swelling under your arm or around your collarbone

Feeling any of this doesn’t mean you have cancer; it just means you should see your doctor to talk about the changes you’ve noticed.

Risk factors

Similar to women, a man’s risk for developing breast cancer increases as he gets older. The average age for a man to be diagnosed with breast cancer is 72.

Additionally, men who have relatives who’ve had breast cancer are also at higher risk. About 20 percent of men who have breast cancer have a close relative—male or female—who has had breast cancer.

Gene mutations can also increase your risk, including the BRCA1 and BRCA2 genes, as well as the CHEK2, PTEN and PALB2 genes.

• Men with a mutation in the BRCA2 gene have a 6 in 100 lifetime risk of developing breast cancer.
• Men with a mutation in the BRCA1 gene have a lifetime risk of about 1 in 100. This includes men whose families do not have a strong breast or ovarian cancer history.

Experts recommend genetic testing for men diagnosed with breast cancer.

Men who have the BRCA1 or BRCA2 mutations should note that they also have an increased risk of pancreatic and prostate cancers. Those with the BRCA2 gene also have an increased risk of melanoma.

Knowing whether you have one of these gene mutations can help guide your treatment and screening.

Additional risk factors include:

• Obesity
• Heavy drinking
• Liver disease
• Exposure to radiation on the chest, such as for treatment for lymphoma
• Certain testicular conditions
• Estrogen treatment
• A rare genetic condition called Klinefelter syndrome
• Excess breast tissue, also known as gynecomastia
• Marijuana use
• Thyroid disease
• Certain occupations, including working in steel or rolling mills or working with organic solvents

Breast cancer is about 100 times less common in white men than in white women. It’s about 70 times less common in black men than in black women.

Diagnosing male breast cancer

Diagnosing male breast cancer starts with providing a complete personal and family medical history, describing your symptoms and being examined by your doctor.

After that, you may have screening with one of a few possible technologies, including a diagnostic mammogram, a breast ultrasound, a magnetic resonance imaging (MRI) scan and/or possibly a test to study your nipple discharge.

Your doctor may also test your blood chemistry to look for unusual amounts of a substance that might suggest disease.

If your diagnostic tests show you may have cancer, the next step is a biopsy. A variety of different biopsies can involve removing cells through a needle, including fine-needle aspiration or core needle biopsy, or removing the whole lump or part of the suspicious area through surgery.

If cancer is found, additional tests will help your doctor know how quickly it may grow, how likely it is to spread or recur and what treatments may be the most appropriate.

Those would include:

• An estrogen and progesterone receptor test that measure the amount of these receptors in the cancer
• A HER2 test to measure the presence and level of HER2 protein

Men tend to be diagnosed with breast cancers that are hormone receptor-positive and HER2-negative.

The spread of cancer from breast to lymph nodes and other parts of the body in men appears to be similar to what women experience.

The “stage” of breast cancer is determined by your care team based on:­

• The size and location of the cancer
• Whether it has spread to nearby lymph nodes or other parts of the body
• The “grade” of the tumor—or how likely it is to grow and spread
• Whether certain biomarkers—hormone receptors or other proteins—are present

Tests to help with determining the stage of the cancer are:

• A biopsy of the sentinel lymph nodes, which are removed during surgery
• A chest X-ray or CT scan
• A bone scan, in which radioactive material is injected into a vein and then can be detected by a scanner
• A PET scan, which scans the body after glucose is injected in a vein (malignant cells are brighter in the picture)

Treatment options

Treatment options for men with breast cancer include what are known as local treatments and systemic treatments.

Local treatments are:

• Breast cancer surgery
• Radiation therapy for breast cancer, which uses radiation to kill cancer cells

Systemic treatments include:

• Chemotherapy, drugs that either kill cancer cells or stop them from dividing
• Hormone therapy, which removes or blocks hormones to stop cancer cells from growing
• Targeted therapy for breast cancer, which uses drugs or other treatments to target specific cancer cells

The type of treatment that’s right for you will depend on the “stage” of your breast cancer, your health and preferences, how fast the cancer is growing and some other factors, including if the cancer cells contain hormone receptors and if they have large amounts of the HER2 protein, which means the cancer is HER2-positive. Cancers with hormone receptors are known as ER-positive or PR-positive.

• Though lumpectomy or breast-conserving surgery is an option for some, most male breast cancer is treated with mastectomy because of the small amount of tissue in a man’s breasts.
• Some men may choose to have breast reconstruction, depending on the amount of tissue removed.
• Tamoxifen, a pill, is often the first targeted drug therapy used for men with hormone receptor-positive cancer, though chemotherapy may be given prior to tamoxifen, depending on the stage of the cancer.
• Chemotherapy for breast cancer is usually the first drug therapy used for men with hormone receptor-negative breast cancer.
• Men with HER2-positive breast cancers may be treated with HER2 targeted therapies. These include trastuzumab, which is also known as Herceptin, plus chemotherapy.

After treatment, you should have long-term monitoring with your care team to watch for possible recurrence of cancer.

Survival rates for breast cancer in men

It’s important to note that statistics and prognosis information are based on previous patients and past treatments, and the outlook may be even more improved when diagnosed today.

The five-year relative survival rate for men with breast cancer overall is 84 percent. This means men with breast cancer are 84 percent as likely to live five years beyond their diagnosis as men in the general population. When the cancer is localized, the five-year survival rate is 96 percent. The 10-year relative survival rate for men with breast cancer is 71 percent.

How soon you’re diagnosed with breast cancer after it starts growing can affect survival rates. However, men have been found to have overall higher rates of death compared to women, which experts attribute to being diagnosed later.