Staging is the process of finding out how far the cancer has spread. The stage of a cancer is one of the most important factors in selecting treatment options.

Depending on the results of your physical exam and biopsy, the doctor may order certain imaging tests, such as a chest x-ray, mammograms, bone scans, computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, and/or positron emission tomography (PET) scans (see below). Blood tests may also be done to evaluate your overall health and to help detect whether the cancer has spread to certain organs.

Imaging tests to look for breast cancer spread

Once breast cancer is diagnosed, one or more of the following tests may be done.

Chest x-ray

This test may be done to see if the breast cancer has spread to the lungs.

Mammogram

If they haven't been done already, more extensive mammograms may be done to get more thorough views of both breasts.

Bone scan

A bone scan can help show if a cancer has metastasized (spread) to the bones. It can be more useful than standard x-rays because it can view all of the bones of the body at the same time.

For this test, a small amount of low-level radioactive material is injected into a vein (intravenously or IV). The substance settles in areas of bone changes throughout the entire skeleton over the course of a couple of hours. You then lie on a table for about 30 minutes while a special camera detects the radioactivity and creates a picture of your skeleton.

Areas of bone changes appear as "hot spots" on your skeleton. They attract the radioactivity. These areas may suggest the presence of metastatic cancer, but arthritis or other bone diseases can also cause the same pattern. To distinguish between these conditions, your cancer care team may use other imaging tests such as simple x-rays or CT or MRI scans to get a better look at the areas that light up, or they may even take biopsy samples of the bone.

Computed tomography (CT) scan

The CT scan is an x-ray test that produces detailed cross-sectional images of your body. Instead of taking a single picture, like a regular x-ray, a CT scanner takes many pictures as it rotates around you while you lie on a table. A computer then combines these pictures into images of slices of the part of your body being studied. In people with breast cancer, this test is most often used to look at the chest and/or abdomen to see if the cancer has spread to other organs.

Before any pictures are taken, you may be asked to drink 1 to 2 pints of a liquid called "oral contrast." This helps outline the intestine so that certain areas are not mistaken for tumors. You may also receive an IV (intravenous) line through which a different kind of contrast dye (IV contrast) is injected. This helps better outline structures in your body.

The injection may cause some flushing (a feeling of warmth, especially in the face). Some people are allergic and get hives. Rarely, more serious reactions like trouble breathing or low blood pressure can occur. Be sure to tell the doctor if you have ever had a reaction to any contrast material used for x-rays.

CT scans take longer than regular x-rays. You need to lie still on a table while they are being done. During the test, the table moves in and out of the scanner, a ring-shaped machine that completely surrounds the table. You might feel a bit confined by the ring you have to lie in while the pictures are being taken.

CT guided needle biopsy: CT scans can also be used to precisely guide a biopsy needle into a suspected area of cancer spread. For this procedure, you remain on the CT scanning table while a radiologist advances a biopsy needle through the skin and toward the location of the mass. CT scans are repeated until the doctors are sure that the needle is within the mass. A fine needle biopsy sample (tiny fragment of tissue) or a core needle biopsy sample (a thin cylinder of tissue about ½-inch long and less than 1/8-inch in diameter) is then removed and sent to be looked at under a microscope.

Magnetic resonance imaging (MRI) scan

MRI scans can be used to look for cancer spread in various parts of the body, just like CT scans. MRI scans are particularly helpful in looking at the brain and spinal cord.

MRI scans use radio waves and strong magnets instead of x-rays. The energy from the radio waves is absorbed and then released in a pattern formed by the type of body tissue and by certain diseases. A computer translates the pattern into a very detailed image of parts of the body. A contrast material called gadolinium is often injected into a vein before the scan to better see details.

MRI scans are a little more uncomfortable than CT scans. First, they often take up to an hour. Second, you have to lie inside a narrow tube, which is confining and can upset people with claustrophobia (a fear of enclosed spaces). Special, "open" MRI machines can sometimes help with this if needed. The machine also makes buzzing and clicking noises that you may find disturbing. Some centers provide headphones with music to block this noise out.

Ultrasound

Ultrasound uses sound waves and their echoes to produce a picture of internal organs or masses. A small microphone-like instrument called a transducer emits sound waves and picks up the echoes as they bounce off body tissues. The echoes are converted by a computer into a black and white image on a computer screen. This test is painless and does not expose you to radiation.

Abdominal ultrasound can be used to look for tumors in your liver or other abdominal organs. When you have an abdominal ultrasound exam, you simply lie on a table and a technician moves the transducer over the skin overlying the part of your body being examined. Usually, the skin is first lubricated with gel.

Positron emission tomography (PET) scan

For a PET scan, glucose (a form of sugar) that contains a radioactive atom is injected into the blood. Because cancer cells in the body are growing rapidly, they absorb large amounts of the radioactive sugar. After about an hour, a special camera is used to create a picture of areas of radioactivity in the body.

A PET scan is useful when your doctor thinks the cancer may have spread but doesn't know where. The picture is not as finely detailed as a CT or MRI scan, but it can provide helpful information about your whole body. Some machines are able to perform both a PET and CT scan at the same time (PET/CT scan). The radiologist can compare areas of higher radioactivity on the PET with the appearance of that area on the CT.

This test can be useful in looking for cancer that has spread to distant organs, but it is not very helpful in looking for small deposits of cancer cells in the lymph nodes under the arm (axillary lymph nodes). It is not often used in early stage breast cancer.

The American Joint Committee on Cancer (AJCC) TNM system

A staging system is a standardized way for the cancer care team to summarize information about how far a cancer has spread. The most common system used to describe the stages of breast cancer is the American Joint Committee on Cancer (AJCC) TNM system.

The stage of a breast cancer can be based either on the results of physical exam, biopsy, and imaging tests (called the clinical stage), or on the results of these tests plus the results of surgery (called the pathologic stage). The staging described here is the pathologic stage, which includes the findings after surgery, when the pathologist has looked at the breast mass and removed lymph nodes. Pathologic staging is likely to be more accurate than clinical staging, as it allows the doctor to get a firsthand impression of the extent of the cancer.

The TNM staging system classifies cancers based on their T, N, and M stages:

• T stands for tumor (its size and how far it has spread within the breast and to nearby organs).

• N stands for spread to lymph nodes (bean-shaped collections of immune system cells that help fight infections and cancers).

• M is for metastasis (spread to distant organs).

Additional letters or numbers appear after T, N, and M to provide more details about the tumor, lymph nodes, and metastasis:

• The letter T followed by a number from 0 to 4 describes the tumor's size and spread to the skin or to the chest wall under the breast. Higher T numbers indicate a larger tumor and/or wider spread to tissues near the breast.

• The letter N followed by a number from 0 to 3 indicates whether the cancer has spread to lymph nodes near the breast and, if so, how many lymph nodes are affected.

• The letter M followed by a 0 or 1 indicates whether the cancer has spread to distant organs -- for example, the lungs or bones.

T categories for breast cancer

TX: Primary tumor cannot be assessed.

T0: No signs of a primary breast tumor.

Tis: Carcinoma in situ (either DCIS or Paget disease of the nipple with no associated tumor mass)

T1: Tumor is 2 cm (3/4 of an inch) or less across.

T2: Tumor is more than 2 cm but not more than 5 cm (2 inches) across.

T3: Tumor is more than 5 cm across.

T4: Tumor of any size growing into the chest wall or skin.

N categories for breast cancer (based on looking at the lymph nodes under a microscope)

Lymph node staging for breast cancer has changed over time as technology has evolved. Earlier methods were useful in finding large deposits of cancer cells in the lymph nodes, but could miss microscopic areas of cancer spread. Over time, newer methods have made it possible to find smaller and smaller deposits of cancer cells. Experts haven't been sure what to do with the new information. Do tiny deposits of cancer cells affect outlook the same way that larger deposits do? How much cancer in the lymph node is needed to see a change in outlook or treatment?

These questions are still being studied, but for now, a deposit of cancer cells must contain at least 200 cells or be at least 0.2 mm across (less than 1/100 of an inch) for it to change the N stage. An area of cancer spread that is smaller than 0.2 mm (or less than 200 cells) doesn't change the stage, but is recorded with abbreviations that reflect the way the cancer spread was detected. The abbreviation "i+" means that cancer cells were only seen when a special stain, called immunohistochemistry, was used. The abbreviation "mol+" is used if the cancer could only be found using a technique called PCR. These very tiny areas are sometimes called isolated tumor cells. If the area of cancer spread is at least 0.2 mm (or 200 cells), but still not larger than 2 mm, it is called a micrometastasis (1 mm is about the size of the width of a grain of rice). Micrometastases are counted only if there aren't any larger areas of cancer spread. Areas of cancer spread larger than 2 mm are known to affect outlook and do change the N stage. These larger areas are sometimes called macrometastases, but may just be called metastases.

NX: Nearby lymph nodes cannot be assessed (for example, removed previously).

N0: Cancer has not spread to nearby lymph nodes.

N0(i+): Tiny amounts of cancer are found in underarm lymph nodes by using special stains. The area of cancer spread contains less than 200 cells and is smaller than 0.2 mm.

N0(mol+): Cancer cells cannot be seen in underarm lymph nodes (even using special stains), but traces of cancer cells were detected using a special test (called PCR)

N1: Cancer has spread to 1 to 3 axillary (underarm) lymph node(s), and/or tiny amounts of cancer are found in internal mammary lymph nodes (those near the breast bone) on sentinel lymph node biopsy.

N1mi: Micrometastases (tiny areas of cancer spread) in 1 to 3 lymph nodes under the arm. The areas of cancer spread in the lymph nodes are 2 mm or less across (but at least 200 cancer cells or 0.2mm across).

N1a: Cancer has spread to 1 to 3 lymph nodes under the arm with at least one area of cancer spread greater than 2 mm across.

N1b: Cancer has spread to internal mammary lymph nodes, but this spread could only be found on sentinel lymph node biopsy (it did not cause the lymph nodes to become enlarged)

N1c: Both N1a and N1b apply.

N2: Cancer has spread to 4 to 9 axillary (under the arm) lymph nodes, or cancer has enlarged the internal mammary lymph nodes (either N2a or N2b, but not both).

N2a: Cancer has spread to 4 to 9 lymph nodes under the arm, with at least one area of cancer spread larger than 2 mm

N2b: Cancer has spread to one or more internal mammary lymph nodes, causing them to become enlarged

N3: One of the following applies:

Cancer has spread to 10 or more axillary lymph nodes, with at least one area of cancer spread greater than 2 mm (N3a).

Cancer has spread to the lymph nodes under the clavicle (collar bone), with at least one area of cancer spread greater than 2 mm (N3a).

Cancer is found in at least one axillary lymph node (with at least one area of cancer spread greater than 2 mm) and has enlarged the internal mammary lymph nodes (N3b).

Cancer was found in 4 or more axillary lymph nodes (with at least one area of cancer spread greater than 2 mm), and tiny amounts of cancer are found in internal mammary lymph nodes on sentinel lymph node biopsy (N3b).

Cancer has spread to the lymph nodes above the clavicle with at least one area of cancer spread greater than 2 mm (N3c).

M categories for breast cancer

MX: Presence of distant spread (metastasis) cannot be assessed.

M0: No distant spread is found on x-rays (or other imaging procedures) or by physical exam.

cM0(i +): Small numbers of cancer cells are found in blood or bone marrow (found only by special tests), or tiny areas of cancer spread (no larger than 0.2 mm) are found in lymph nodes away from the breast

M1: Spread to distant organs is present. (The most common sites are bone, lung, brain, and liver.)

Breast cancer stage grouping

Once the T, N, and M categories have been determined, this information is combined in a process called stage grouping. Cancers with similar stages tend to have a similar outlook and thus are often treated in a similar way. Stage is expressed in Roman numerals from stage I (the least advanced stage) to stage IV (the most advanced stage). Non-invasive cancer is listed as stage 0.

Stage 0: Tis, N0, M0: This is ductal carcinoma in situ (DCIS), the earliest form of breast cancer. In DCIS, cancer cells are still within a duct and have not invaded deeper into the surrounding fatty breast tissue. Paget disease of the nipple (without an underlying tumor mass) is also stage 0. In all cases the cancer has not spread to lymph nodes or distant sites.

Stage IA: T1, N0, M0: The tumor is 2 cm (about 3/4 of an inch) or less across and has not spread to lymph nodes or distant sites.

Stage IB: T0 or T1, N1mi, M0: The tumor is 2 cm or less across (or is not found) with micrometastases in 1 to 3 axillary lymph nodes (the cancer in the lymph nodes is greater than 0.2 mm across and/or more than 200 cells but is not larger than 2 mm). The cancer has not spread to distant sites.

Stage IIA: One of the following applies:

T0 or T1, N1 (but not N1mi), M0: The tumor is 2 cm or less across (or is not found) (T1 or T0) and either:

• It has spread to 1 to 3 axillary lymph nodes (N1a), but not to distant sites (M0), OR

• Tiny amounts of cancer are found in internal mammary lymph nodes on sentinel lymph node biopsy (N1b), but not to distant sites (M0), OR.

• It has spread to 1 to 3 axillary lymph nodes, and tiny amounts of cancer are found in internal mammary lymph nodes on sentinel lymph node biopsy (N1c), but not to distant sites (M0).

OR

T2, N0, M0: The tumor is larger than 2 cm across and less than 5 cm (T2), but it hasn't spread to the lymph nodes (N0) or to distant sites (M0).

Stage IIB: One of the following applies:

T2, N1, M0: The tumor is larger than 2 cm and less than 5 cm across (T2). It has spread to 1 to 3 axillary lymph nodes and/or tiny amounts of cancer are found in internal mammary lymph nodes on sentinel lymph node biopsy (N1). It has not spread to distant sites (M0).

OR

T3, N0, M0: The tumor is larger than 5 cm across but does not grow into the chest wall or skin (T3). It has not spread to lymph nodes (N0) or to distant sites (M0).

Stage IIIA: One of the following applies:

T0 to T2, N2, M0: The tumor is not more than 5 cm across (or cannot be found) (T0 to T2). It has spread to 4 to 9 axillary lymph nodes, or it has enlarged the internal mammary lymph nodes (N2). It has not spread to distant sites (M0).

OR

T3, N1 to N2, M0: The tumor is larger than 5 cm across but does not grow into the chest wall or skin (T3). It has spread to 1 to 9 axillary nodes, or to internal mammary nodes (N1 or N2). It has not spread to distant sites (M0)

Stage IIIB: T4, N0 to N2, M0: The tumor has grown into the chest wall or skin (T4), and one of the following applies:

• It has not spread to the lymph nodes (N0).

• It has spread to 1 to 3 axillary lymph nodes and/or tiny amounts of cancer are found in internal mammary lymph nodes on sentinel lymph node biopsy (N1).

• It has spread to 4 to 9 axillary lymph nodes, or it has enlarged the internal mammary lymph nodes (N2).

The cancer hasn't spread to distant sites (M0).

Stage IIIC: any T, N3, M0: The tumor is any size (or can't be found) (any T), and one of the following applies:

• Cancer has spread to 10 or more axillary lymph nodes (N3).

• Cancer has spread to the lymph nodes under the clavicle (collar bone) (N3).

• Cancer has spread to the lymph nodes above the clavicle (N3).

• Cancer involves axillary lymph nodes and has enlarged the internal mammary lymph nodes (N3).

• Cancer involves 4 or more axillary lymph nodes, and tiny amounts of cancer are found in internal mammary lymph nodes on sentinel lymph node biopsy.

The cancer hasn't spread to distant sites (M0).

Stage IV: any T, any N, M1: The cancer can be any size and may or may not have spread to nearby lymph nodes. It has spread to distant organs (the most common sites are the bone, liver, brain, or lung), or to lymph nodes far from the breast.

If you have any questions about the stage of your cancer and what it might mean in your case, be sure to ask your doctor.

Breast cancer survival rates by stage

Survival rates are often used by doctors as a standard way of discussing a person's prognosis (outlook). Some patients with cancer may want to know the survival statistics for people in similar situations, while others may not find the numbers helpful, or may even not want to know them. Whether or not you want to read about the survival statistics below for male breast cancer is up to you.

The 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed. Of course, many people live much longer than 5 years (and many are cured).

Five-year relative survival rates assume that some people will die of other causes and compare the observed survival with that expected for people without the cancer. This is a more accurate way to describe the prognosis for patients with a particular type and stage of cancer.

In order to get 5-year survival rates, doctors have to look at people who were treated at least 5 years ago. Improvements in treatment since then may result in a more favorable outlook for men now being diagnosed with breast cancer.

Survival rates are often based on previous outcomes of large numbers of people who had the disease, but they cannot predict what will happen in any particular person's case. Many other factors may affect a person's outlook, such as their overall health, what treatment they receive, and how well the cancer responds to treatment.. Your doctor can tell you how the numbers below may apply to you, as he or she is familiar with the aspects of your particular situation.

The numbers below come from the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) database. These statistics include only male breast cancer cases.

Last Medical Review: 01/14/2010
Last Revised: 01/14/2010