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

Staging 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?"

Because carcinoid tumors are uncommon, there is no official staging system for these tumors. Generally, the staging system that most doctors use for lung carcinoid tumors is the same one used to stage non-small cell lung cancer.

The TNM staging system

The system most often used to describe the growth and spread of carcinoids and of non-small cell lung cancers is 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 that are important in fighting infections.

• 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

T0: No evidence of a primary tumor.

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

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

• It is larger than 3 centimeters (cm) across.
• 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 can be any size and has 1 or more of the following features:

• 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 (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.

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

• A tumor of any size has grown into the space behind the chest bone and in front of the heart (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 the same lobe of a lung.
• There is a fluid containing cancer cells in the space surrounding the lung (a malignant pleural effusion).

N categories

NX: Nearby lymph nodes cannot be assessed.

N0: No spread to nearby lymph nodes.

N1: 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: Spread to lymph nodes around the carina (the point where the windpipe splits into the left and right bronchi) or in the space behind the breastbone and in front of the heart (mediastinum). Affected lymph nodes are on the same side as the primary tumor.

N3: 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.

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.

Stage grouping

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

Stage IA

T1, N0, M0: The cancer is no larger than 3 centimeters (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

T2, N0, M0: The cancer has 1 or more of the following features:

• The main tumor is larger than 3 cm across.
• 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

T1, N1, M0: The cancer is no larger than 3 centimeters, 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). It has not spread to distant sites.

Stage IIB

There are 2 combinations of categories that make up this stage.

T2, N1, M0: The cancer has 1 or more of the following features:

• The main tumor is larger than 3 cm across.
• 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). It has not spread to distant sites.

T3, N0, M0: The main tumor can be any size and has 1 or more of the following features:

• 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 (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.

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

Stage IIIA

There are 4 main combinations of categories that make up this stage.

T1, N2, M0: The cancer is no larger than 3 centimeters, has not grown into the membranes that surround the lungs, and does not affect the main branches of the bronchi. The cancer has spread to lymph nodes around the carina (the point where the windpipe splits into the left and right bronchi) or in the space behind the breastbone and in front of the heart (mediastinum). Affected lymph nodes are on the same side as the primary tumor. The cancer has not spread to distant sites.

T2, N2, M0: The cancer has 1 or more of the following features:

• The main tumor is larger than 3 cm across.
• 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 also spread to lymph nodes around the carina (the point where the windpipe splits into the left and right bronchi) or in the space behind the breastbone and in front of the heart (mediastinum). Affected lymph nodes are on the same side as the primary tumor. The cancer has not spread to distant sites.

T3, N1, M0: The tumor can be any size and has 1 or more of the following features:

• 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 2 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.

It has also spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). It has not spread to distant sites.

T3, N2, M0: The tumor can be any size and has 1 or more of the following features:

• 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 (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.

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 behind the breastbone and in front of the heart (mediastinum). Affected lymph nodes are on the same side as the primary tumor. The cancer has not spread to distant sites.

Stage IIIB

There are 2 combinations of categories that 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.

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

• A tumor of any size has grown into the space behind the chest bone and in front of the heart (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 the same lobe of a lung.
• There is a fluid containing cancer cells in the space surrounding the lung (a malignant pleural effusion).

The cancer may or may not have spread to nearby lymph nodes. It has not spread to distant sites.

Stage IV

Any T, Any N, M1: 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.

Survival rates for lung carcinoid tumors

Survival rates are a way for doctors to discuss and compare the prognosis (outlook) for patients, usually based on the stage of the cancer or other traits. For example, the 5-year survival rate refers to the percentage of patients who live at least 5 years after being diagnosed (although many patients live much longer than this).

Overall, the 5-year survival rate for patients with typical lung carcinoids is around 85% to 90%, and the 5-year survival rate for patients with atypical lung carcinoids is around 50% to 60%. These ranges reflect different survival rates quoted by several medical journal articles.

Because these cancers are not common, it is hard to find accurate survival rates based on the TNM stage of the cancer. But as a general rule, survival rates are likely to be higher than those listed above for people with a lung carcinoid that is still localized (confined to the area where it started), while the rates are likely to be lower for those with cancers that have metastasized.

Even with typical carcinoids that appear to have been treated successfully, in a small number of cases the cancer can recur many years later, which is why doctors often advise close follow-up for at least 10 years.

There are some important points to keep in mind when looking at survival rates such as the numbers above.

These numbers are derived from patients treated at least several years ago. Improvements in treatment since then mean that the survival rates for people now being diagnosed with these cancers may be higher.

Survival statistics can sometimes be useful as a general guide, but they may not accurately represent any one person's prognosis. A number of factors other than the type and extent of the cancer may also affect outlook, including a person's general health and the response of the cancer to treatment.

Your doctor is likely to be a good source as to whether the numbers above may apply to you, as he or she is familiar with the aspects of your particular situation.

Last Medical Review: 03/09/2009
Last Revised: 03/09/2009