How are lung carcinoid tumors staged?

Staging is a process of finding out how far a cancer has spread. Your treatment and prognosis (outlook) depend, to a large extent, on the cancer's stage.

The stage of the cancer is based on the results of the physical exam, biopsies, and imaging tests (CT scan, PET scan, etc.), which are described in the section, “How are lung carcinoid tumors diagnosed?”

The staging system for lung carcinoid tumors is the same one used to stage other types of lung cancer – the American Joint Committee on Cancer (AJCC) TNM staging system. The TNM system describes 3 key pieces of information:

• T indicates the size of the main (primary) tumor and whether it has grown into nearby areas.
• N describes how much the cancer has spread to nearby (regional) lymph nodes. Lymph nodes are small bean-shaped collections of immune system cells to which cancers often spread.
• M indicates whether the cancer has spread (metastasized) to other organs of the body. (The most common site is the liver.)

Numbers or letters appear after T, N, and M to provide more details about each of these factors. The numbers 0 through 4 indicate increasing severity. The letter X means cannot be assessed because the information is not available.

T categories

TX: The main (primary) tumor can't be assessed, or cancer cells were seen on sputum cytology or bronchial washings but no tumor can be found.

T0: There is no evidence of a primary tumor.

Tis: The cancer is found only in the top layers of cells lining the air passages. It has not invaded into deeper lung tissues. This stage is also known as carcinoma in situ.

T1: The tumor is no larger than 3 cm (slightly less than 1¼ inches) across. It has not reached the membranes that surround the lungs (visceral pleura), and it does not affect the main branches of the bronchi.

• T1a: The tumor is 2 cm (about 4/5 of an inch) or less across.
• T1b: The tumor is larger than 2 cm but not larger than 3 cm across.

T2: The tumor has 1 or more of the following features:

• It is larger than 3 cm but not larger than 7 cm across. If the tumor is 5 cm or less across (but still larger than 3 cm), it is called T2a. If the tumor is larger than 5 cm across (but not larger than 7 cm), it is called T2b.
• It involves a main bronchus, but is not closer than 2 cm (about ¾ inch) to the carina (the point where the windpipe splits into the left and right main bronchi).
• It has grown into the membranes that surround the lungs (visceral pleura).
• The tumor partially clogs the airways, but this has not caused the entire lung to collapse or develop pneumonia.

T3: The tumor has 1 or more of the following features:

• It is larger than 7 cm across.
• It has grown into the chest wall, the breathing muscle that separates the chest from the abdomen (diaphragm), the membranes surrounding the space between the lungs (mediastinal pleura), or membranes of the sac surrounding the heart (parietal pericardium).
• It invades a main bronchus and is closer than 2 cm (about ¾ inch) to the carina, but it does not involve the carina itself.
• It has grown into the airways enough to cause an entire lung to collapse or to cause pneumonia in the entire lung.
• Two or more separate tumor nodules are present in the same lobe of a lung

T4: The cancer has 1 or more of the following features:

• A tumor of any size has grown into the space between the lungs (mediastinum), the heart, the large blood vessels near the heart (such as the aorta), the windpipe, the esophagus (tube connecting the throat to the stomach), the backbone, or the carina.
• Two or more separate tumor nodules are present in different lobes of the same lung.

N categories

NX: Nearby lymph nodes cannot be assessed.

N0: There is no spread to nearby lymph nodes.

N1: The cancer has spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). Affected lymph nodes are on the same side as the primary tumor(s).

N2: The cancer has spread to lymph nodes around the carina (the point where the windpipe splits into the left and right bronchi), or it has spread to lymph nodes in the space between the lungs (mediastinum) on the same side as the primary tumor.

N3: The cancer has spread to lymph nodes near the collarbone on either side, and/or spread to hilar or mediastinal lymph nodes on the side opposite the primary tumor.

M categories

M0: No spread to distant organs or areas. This includes other lobes of the lungs, lymph nodes further away than those mentioned in the N stages above, and other organs or tissues such as the liver, bones, or brain.

M1: The cancer has spread to 1 or more distant sites. This can be to another lobe of the lung, to distant lymph nodes, or to other organs.

M1a: Any of the following:

• The cancer has spread to the other lung.
• Cancer cells are found in the fluid around the lung (called a malignant pleural effusion).
• Cancer cells are found in the fluid around the heart (called a malignant pericardial effusion).

M1b: The cancer has spread to distant organs or lymph nodes.

Stage grouping for lung cancer and lung carcinoid

Once the T, N, and M categories have been determined, this information is combined (stage grouping) to assign an overall stage of 0, I, II, III, or IV. Some stages are subdivided into A and B. The stages identify tumors that have a similar prognosis and so they are treated in a similar way. Patients with lower stage numbers tend to have a better prognosis.

Occult cancer

TX, N0, M0: Cancer cells are seen in a sample of sputum or other lung fluids, but the location of the cancer can't be determined.

Stage 0

Tis, N0, M0: The cancer is found only in the top layers of cells lining the air passages. It has not invaded deeper into other lung tissues and has not spread to lymph nodes or distant sites.

Stage IA

T1, N0, M0: The cancer is no larger than 3 cm across, has not reached the membranes that surround the lungs, and does not affect the main branches of the bronchi. It has not spread to lymph nodes or distant sites.

Stage IB

T2a, N0, M0: The cancer has 1 or more of the following features:

• The main tumor is between 3 and 5 cm across (larger than 3 cm but not larger than 5 cm).
• The tumor involves a main bronchus, but is not within 2 cm of the carina.
• The tumor has grown into the visceral pleura (the membranes surrounding the lungs).
• The cancer is partially clogging the airways.

The cancer has not spread to lymph nodes or distant sites.

Stage IIA

Three main combinations of categories make up this stage.

T1, N1, M0: The cancer is no larger than 3 cm across, has not grown into the membranes that surround the lungs, and does not affect the main branches of the bronchi. It has spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). These lymph nodes are on the same side as the cancer. It has not spread to distant sites.

OR

T2a, N1, M0: The cancer has 1 or more of the following features:

• The main tumor is between 3 and 5 cm across (larger than 3 cm but not larger than 5 cm).
• The tumor involves a main bronchus, but is not within 2 cm of the carina.
• The tumor has grown into the visceral pleura (the membranes surrounding the lungs).
• The cancer is partially clogging the airways.

It has also spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). These lymph nodes are on the same side as the cancer. It has not spread to distant sites.

OR

T2b, N0, M0: The cancer has 1 or more of the following features:

• The main tumor is between 5 and 7 cm across (larger than 5 cm but not larger than 7 cm).
• The tumor involves a main bronchus, but is not within 2 cm of the carina.
• The tumor has grown into the visceral pleura (the membranes surrounding the lungs).
• The cancer is partially clogging the airways.

The cancer has not spread to lymph nodes or distant sites.

Stage IIB

Two combinations of categories make up this stage.

T2b, N1, M0: The cancer has 1 or more of the following features:

• The main tumor is between 5 and 7 cm across (larger than 5 cm but not larger than 7 cm).
• The tumor is larger than 5 cm across and involves a main bronchus, but is not within 2 cm of the carina.
• The tumor is larger than 5 cm across and has grown into the visceral pleura (the membranes surrounding the lungs).
• The tumor is larger than 5 cm across and is partially clogging the airways.

It has also spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). These lymph nodes are on the same side as the cancer. It has not spread to distant sites.

OR

T3, N0, M0: The main tumor has 1 or more of the following features:

• It is larger than 7 cm across.
• It has grown into the chest wall, the breathing muscle that separates the chest from the abdomen (diaphragm), the membranes surrounding the space between the lungs (mediastinal pleura), or membranes of the sac surrounding the heart (parietal pericardium).
• It invades a main bronchus and is closer than 2 cm (about ¾ inch) to the carina, but it does not involve the carina itself.
• It has grown into the airways enough to cause an entire lung to collapse or to cause pneumonia in the entire lung.
• Two or more separate tumor nodules are present in the same lobe of a lung.

The cancer has not spread to lymph nodes or distant sites.

Stage IIIA

Three main combinations of categories make up this stage.

T1 to T3, N2, M0: The tumor can be any size or have any of the following features

• The tumor involves a main bronchus without growing into the carina.
• The tumor has grown into the visceral pleura (the membranes surrounding the lungs).
• The cancer is partially clogging the airways.
• It has grown into the airways enough to cause an entire lung to collapse or to cause pneumonia in the entire lung.
• It has grown into the chest wall, the breathing muscle that separates the chest from the abdomen (diaphragm), the membranes surrounding the space between the two lungs (mediastinal pleura), or membranes of the sac surrounding the heart (parietal pericardium).
• Two or more separate tumor nodules are present in the same lobe of a lung.

The cancer has also spread to lymph nodes around the carina (the point where the windpipe splits into the left and right bronchi) or in the space between the lungs (mediastinum). These lymph nodes are on the same side as the main lung tumor. The cancer has not spread to distant sites.

OR

T3, N1, M0: The tumor has 1 or more of the following features:

• It is larger than 7 cm across.
• It has grown into the chest wall, the breathing muscle that separates the chest from the abdomen (diaphragm), the membranes surrounding the space between the two lungs (mediastinal pleura), or membranes of the sac surrounding the heart (parietal pericardium).
• It invades a main bronchus and is closer than 2 cm to the carina, but it does not involve the carina itself.
• Two or more separate tumor nodules are present in the same lobe of a lung.
• It has grown into the airways enough to cause an entire lung to collapse or to cause pneumonia in the entire lung.

It has also spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). These lymph nodes are on the same side as the cancer. It has not spread to distant sites.

OR

T4, N0 or N1, M0: The cancer has 1 or more of the following features:

• A tumor of any size has grown into the space between the lungs (mediastinum), the heart, the large blood vessels near the heart (such as the aorta), the windpipe, the esophagus (tube connecting the throat to the stomach), the backbone, or the carina.
• Two or more separate tumor nodules are present in different lobes of the same lung.

It may also have spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). Any affected lymph nodes are on the same side as the cancer. It has not spread to distant sites.

Stage IIIB

Two combinations of categories make up this stage.

Any T, N3, M0: The cancer can be of any size. It may or may not have grown into nearby structures or caused pneumonia or lung collapse. It has spread to lymph nodes near the collarbone on either side, and/or has spread to hilar or mediastinal lymph nodes on the side opposite the primary tumor. The cancer has not spread to distant sites.

OR

T4, N2, M0: The cancer has 1 or more of the following features:

• A tumor of any size has grown into the space between the lungs (mediastinum), the heart, the large blood vessels near the heart (such as the aorta), the windpipe, the esophagus (tube connecting the throat to the stomach), the backbone, or the carina.
• Two or more separate tumor nodules are present in different lobes of the same lung.

The cancer has also spread to lymph nodes around the carina or in the space between the lungs (mediastinum). Affected lymph nodes are on the same side as the main lung tumor. It has not spread to distant sites.

Stage IV

Two combinations of categories make up this stage.

Any T, any N, M1a: The cancer can be any size and may or may not have grown into nearby structures or reached nearby lymph nodes. In addition, any of the following is true:

• The cancer has spread to the other lung.
• Cancer cells are found in the fluid around the lung (called a malignant pleural effusion).
• Cancer cells are found in the fluid around the heart (called a malignant pericardial effusion).

OR

Any T, any N, M1b: The cancer can be any size and may or may not have grown into nearby structures or reached nearby lymph nodes. It has spread to distant sites, such as another organ.