Breast Cancer in Men

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Early Detection, Diagnosis, and Staging TOPICS

How is breast cancer in men staged?

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. Blood tests may also be done to evaluate your overall health and to help detect whether the cancer has spread to certain organs.

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 staging system used for breast cancer in men is the same as the one used for breast cancer in women.

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:

  • 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 (includes T1a, b, and c): 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 staining technique, called immunohistochemistry, was used. The abbreviation mol+ is used if the cancer could only be found using a technique called PCR. PCR is a molecular test that can find very small numbers of cells that cannot even be seen using special stains 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, they were 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 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 and at least one area of cancer spread is 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, and at least one area of cancer spread is larger than 2 mm
  • N2b: Cancer has spread to one or more internal mammary lymph nodes, causing them to become enlarged

N3: Any of the following:

  • N3a: either:
  • Cancer has spread to 10 or more axillary lymph nodes, and at least one area of cancer spread is greater than 2 mm.
  • Cancer has spread to the lymph nodes under the clavicle (collar bone), and at least one area of cancer spread is greater than 2 mm.
  • N3b: either:
  • Cancer is found in at least one axillary lymph node (and at least one area of cancer spread is greater than 2 mm) and has enlarged the internal mammary lymph nodes.
  • Cancer was found in 4 or more axillary lymph nodes (and at least one area of cancer spread is greater than 2 mm), and tiny amounts of cancer are found in internal mammary lymph nodes on sentinel lymph node biopsy.
  • N3c: Cancer has spread to the lymph nodes above the clavicle and at least one area of cancer spread is greater than 2 mm.

M categories for breast cancer

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), a pre-cancer of the breast. Many consider this 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 I: Includes stages IA and IB

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 II: Includes stages IIA and IIB

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 in distant sites (M0), OR.
  • The cancer 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 it has not spread 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 III: Includes stages IIIA, IIIB, and IIIC

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.


Last Medical Review: 10/10/2014
Last Revised: 10/10/2014