Early Detection, Diagnosis, and Staging of Breast Cancer in Men

A mammogram is a low dose x-ray used to look for changes in breast tissue. It’s called a diagnostic mammogram when it’s done because of signs or symptoms, rather than as a screening test for people without symptoms.

A mammogram uses an x-ray machine designed for looking at breast tissue. The breast is pressed between 2 plates to flatten and spread the tissue. The compression only lasts a few seconds. It may be briefly uncomfortable, but it’s necessary to get a better picture. Sometimes, special images called cone or spot views with magnification are taken to see a small area more closely.

Mammogram results may suggest that a biopsy is needed to find out if the abnormal area is cancer.

Breast ultrasound uses sound waves instead of radiation to make pictures of the inside of the breast.

A gel is put on the skin, and a wand-like tool called a transducer is moved over the area. You might feel some pressure, but it should not be painful. The transducer sends out sound waves and picks up the echoes as they bounce off body tissues. A computer turns these echoes into an image.

Breast ultrasound is often done after a mammogram or physical exam to help tell the difference between fluid-filled cysts, which are unlikely to be cancer, and solid masses, which might need more testing. It can also be used to check for enlarged lymph nodes under the arm and to guide a needle for a biopsy sample to look for cancer cells in the breast or lymph nodes.

A core needle biopsy is the most common type of breast biopsy.

The doctor uses a wide, hollow needle to take out cylinders (cores) of breast tissue from a suspicious area. Several cylinders are often removed.

The biopsy is done with local numbing medicine and with the doctor either feeling the abnormal area or using an imaging test (like ultrasound or MRI) to find the area to biopsy.

In addition to the standard CNB, there are two other types of CNBs:

• Stereotactic core needle biopsy
• Vacuum-assisted core biopsy

A CNB usually provides enough breast tissue to make the diagnosis and to do tests to learn more about the cancer (see below), if needed. But if the results of the CNB do not give a clear diagnosis, or your doctor still has concerns, you might need a second biopsy or a different type of biopsy.

For an FNA biopsy, the doctor uses a very thin, hollow needle attached to a syringe to withdraw (aspirate) a small amount of tissue or fluid from a suspicious area. A local anesthetic (numbing medicine) is sometimes used.

If the lump can be felt, the doctor will guide the needle into it by touch. If not, they may do an ultrasound-guided biopsy, watching the needle on a screen while moving it into the right area.

An FNA biopsy is the easiest type of biopsy to have, but it’s less useful for breast biopsies than CNB because it removes less tissue. This means an FNA:

• Can sometimes miss a cancer if the needle does not go into the cancer cells
• Might not provide a big enough sample to do all the lab tests needed if cancer is found (see below)
• Might not give a clear diagnosis, which means another biopsy might still be needed

An FNA biopsy is more often used to check for cancer cells in nearby lymph nodes.

Most breast cancers can be diagnosed with a needle biopsy. Rarely, a surgical (open) biopsy is needed to remove all or part of the lump for testing.

There are 2 types of surgical biopsies:

• An incisional biopsy removes only part of the suspicious area, enough to make a diagnosis.
• An excisional biopsy removes the entire tumor or abnormal area, with or without trying to take out an edge of normal breast tissue (depending on the reason for the biopsy).

Most often, the surgeon removes the entire mass or abnormal area, as well as a surrounding margin of normal-appearing breast tissue.

The breast cancer type is based on the type of cells where the cancer started. For example, it may be:

• Ductal carcinoma if it started in the ducts
• Lobular carcinoma if it started in the lobules
• Sarcoma if it started in the connective tissue

If there is enough tissue, the pathologist may also determine if the cancer is:

• In situ (only in the layers where it started)
• Invasive (growing into deeper layers of breast tissue, and possibly farther)

This information is used to name the exact cancer type, such as:

• Invasive ductal carcinoma (IDC)
• Invasive lobular carcinoma (ILC)
• Ductal carcinoma in situ (DCIS)

Learn more about these and other types of breast cancer in men.

Invasive breast cancers (IDC and ILC) are given a grade (from 1 to 3), based on how abnormal the cells look and how they are growing—that is, if they still form the structures seen in normal breast tissue.

• Grade 1 or well differentiated: The cancer looks a lot like normal breast tissue, so it is less likely to grow and spread quickly.
• Grade 2 or moderately differentiated: The cancer is between grades 1 and 3.
• Grade 3 or poorly differentiated: The cancer looks very different from normal breast tissue and will probably grow and spread faster.

Ductal carcinoma in situ (DCIS) is also graded, but the grade is based only on how abnormal the cancer cells look. Areas of necrosis (dead or dying cancer cells) are also noted. If there is necrosis, it means the tumor is growing more quickly. See Your Breast Pathology Report: Ductal Carcinoma In Situ for more on how DCIS grades are described.

Estrogen and progesterone receptor (ER and PR) status

Normal breast cells have receptors (proteins) that attach to the hormones estrogen and progesterone. Attaching to these receptors is how the hormones affect the growth of these cells.

Breast cancer cells may have one, both, or neither of these receptors.

• ER-positive (ER+) breast cancers have estrogen receptors.
• PR-positive (PR+) breast cancers have progesterone receptors.
• Hormone receptor-positive (HR+) breast cancers have either or both receptors.
• Hormone receptor-negative (HR-) breast cancers have neither receptor.

Knowing the hormone receptor status is important in deciding treatment options. Hormone therapies can be used to help treat HR-positive cancers, but they aren’t likely to be helpful for HR-negative cancers. HR-positive cancers also tend to grow more slowly than those that are HR-negative.

Most male breast cancers are HR-positive.

HER2 status

A small number of breast cancers in men are HER2-positive. This means the cells have too much of a protein called HER2 (also known as HER2/neu) that helps the cells grow. These cancers tend to grow and spread faster than other breast cancers. But they’re also much more likely to respond to treatment with drugs that target the HER2 protein.

All invasive breast cancers should be tested for HER2, either on the biopsy sample or when the tumor is removed with surgery.

To test for HER2, an immunohistochemistry (IHC) test is often done first. This is commonly followed by a fluorescence in situ hybridization (FISH) test to help further classify the tumor type.

• HER2-negative means the IHC result is 0 with no cell membrane staining. These cancers do not respond to treatment with drugs that target HER2.
• HER2-ultralow means the IHC result is 0 with membrane staining (HER2+ staining in more than 0% but no more than 10% of tumor cells). These cancers may respond to certain drugs that target HER2 called antibody-drug conjugates.
• HER2-low means the IHC is 1+ OR if the IHC is 2+ but FISH is negative. These cancers may respond to certain drugs called antibody-drug conjugates.
• HER2-positive means the IHC is 2+ and the FISH is positive OR IHC is 3+. These cancers are usually treated with drugs that target HER2.

See How Biopsy and Cytology Samplese Are Tested for Cancer and Your Pathology Report: Breast Cancer to learn more about these tests.

Classifying breast cancer based on hormone receptors and HER2 status

Invasive breast cancers are often divided into 4 groups based on whether they have hormone receptors (HR) – meaning estrogen receptors (ER) and/or progesterone receptors (PR) – and whether they make too much of the HER2 protein. This helps determine treatment options:

• HR-positive, HER2 positive cancers typically respond to both hormone therapy and HER2-targeted drugs.
• HR-positive, HER2 negative cancers typically respond to hormone therapy but not HER2-targeted drugs.
• HR-negative, HER2 positive cancers typically respond to HER2-targeted drugs but not hormone therapy.
• Triple-negative breast cancers (TNBCs) are negative for HER2 and both hormone receptors. They typically do not respond to either HER2-targeted drugs or hormone therapy.

Molecular tests (sometimes called biomarker or genomic tests) are often done to look for specific gene or protein changes in the cancer cells. Results of these tests can help guide treatment.

Targeted therapy drugs may be helpful if changes are found in these genes:

• BRCA1 or BRCA2
• PIK3CA, AKT1, or PTEN
• NTRK

Immunotherapy may be an option if the cancer shows:

• Microsatellite instability (MSI) or defects in mismatch repair genes (dMMR)
• High tumor mutational burden (TMB)
• High levels of the PD-L1 protein

Hormone therapy may be helpful for some cancers with changes in the ESR1 gene.

Gene expression tests (or gene expression profiling) look at the patterns of certain genes in cancer cells. Examples include:

• Oncotype DX
• MammaPrint
• Prosigna (PAM50)
• EndoPredict
• Breast Cancer Index (BCI)

These tests can help predict how likely early-stage (stage 1 or 2) breast cancers are to come back (recur) after initial treatment.

Doctors can use this information to know who will most likely benefit from treatments such as chemotherapy after surgery or long-term hormone therapy.

Most research on these tests has been in women, so their usefulness in men with breast cancer is not completely clear. Still, some doctors may use them to help guide treatment decisions for men with early-stage breast cancer. Ask your doctor if one of these tests might be helpful for you.

These tests look at the DNA in breast cancer cells to help predict how fast the cancer is growing.

They may provide information about long-term outcomes but are generally less important for guiding treatment than many of the tests above.

The cell proliferation rate is how quickly cancer cells copy their DNA and divide. It can be determined in 2 ways:

• The Ki-67 test looks for the Ki-67 protein, which is found in actively dividing cells.
• The S-phase fraction test measures the percentage of cells in a sample that are copying their DNA as they get ready to divide.

A high result on either test means the cancer is growing more quickly.

Ploidy describes the amount of DNA in the cancer cells:

• Diploid: A normal amount of DNA. These cancers tend to grow and spread more slowly.
• Aneuploid: An abnormal amount of DNA. These cancers tend to grow and spread faster.

Your doctor will probably want to biopsy nearby lymph nodes (under the arm and/or near the collarbone) to check them for cancer spread. When breast cancer spreads, most often it goes to these nodes first.

Lymph node biopsies can be done in different ways, depending on the situation:

• Needle biopsy (typically a fine needle aspiration, or FNA): If the doctor is concerned about an enlarged lymph node (either felt on exam or seen on an imaging test). See above for more on needle biopsies.
• Sentinel lymph node biopsy (SLNB): If no lymph nodes are enlarged. This biopsy involves injecting a radioactive substance and/or dye to find the node the cancer would likely spread to first.
• Axillary lymph node dissection (ALND): If several lymph nodes are enlarged, or if an SLNB finds cancer in the lymph node. This surgery involves removing all of the lymph nodes in the area.

For more on how SLNB and ALND are done, see Surgery for Breast Cancer in Men.

A chest x-ray may be done to see if the breast cancer has spread to the lungs.

A CT scan uses x-rays taken from different angles, which are combined by a computer to make detailed pictures of the organs. This test is most often used to look at the chest and/or belly (abdomen) to see if breast cancer has spread to other organs, like the lungs or liver.

CT-guided needle biopsy: If a suspected area of cancer is deep within your body, a CT scan might be used to guide a biopsy needle into this area to get a tissue sample to check for cancer.

An MRI scan makes detailed pictures using radio waves and strong magnets instead of x-rays. This test can be used to look at the breast area or to look for spread of cancer to other parts of the body, such as the brain and spinal cord.

For an ultrasound, a wand that gives off sound waves is moved over the skin to take pictures of the inside of the body. A gel is often put on your skin first.

This test can be used to diagnose breast cancer, but it can also be used to look for cancer that has spread to other parts of the body, such as the liver.

For this test, a slightly radioactive form of sugar is put into a vein and travels throughout the body. Cancer cells absorb high amounts of this sugar. A special camera then takes pictures that show the areas where the sugar collected throughout the body.

A PET scan can be useful when your doctor thinks the cancer may have spread but doesn't know where. The picture is not as detailed as a CT or MRI scan, but it can provide helpful information about your whole body.

PET/CT scan: Often a PET scan is combined with a CT scan using a special machine that can do both at the same time. This lets the doctor compare areas of higher radioactivity on the PET scan with a more detailed picture on the CT scan.

For a bone scan, a small amount of low-level radioactive material is injected into your blood and collects mainly in abnormal areas of bone. This test can help show if cancer has spread to your bones. It can show all of the bones in the body at the same time and can find small areas of cancer spread not seen on plain x-rays.

This test typically isn’t needed if a PET scan is being done.