Lung cancer often spreads to the brain or bones. Knowing the stage (stage) of the disease helps the doctor plan lung cancer treatment. Some of the tests used to determine whether the cancer has spread are:

CT scans or CT scan. A computer linked to an X-ray machine creates a series of detailed pictures of areas inside the body.

MRI (magnetic resonance imaging). A powerful magnet linked to a computer produces detailed pictures of areas inside the body.

Radionuclide studies. The scans with radionuclides (radioactive isotopes) can show whether cancer has spread to other organs including the liver. The patient swallows or receives an injection of a mildly radioactive substance. A machine (scanner) measures and records the level of radioactivity in certain organs to reveal abnormal areas.

Bone scans. The scanogram bone, a type of radionuclide study can show whether cancer has spread to the bones. Is injected into the vein a small amount of a radioactive substance that travels through the bloodstream and concentrates in the areas of abnormal bone growth. An instrument called a scanner measures the radioactivity levels in these areas and records them on x-ray film

Mediastinoscopy / mediastinotomy. A mediastinoscopy can help show whether cancer has spread to lymph nodes in the chest. Using a light optical instrument called an endoscope, the doctor examines the center of the chest (mediastinum) and nearby lymph nodes. At mediastinoscopy, the scope is inserted through a small incision in the neck in mediastinotomy, an incision is made in the chest. In either of the two procedures, the endoscope is also used to collect a tissue sample. The patient receives general anesthesia.

The reported staging the spread of cancer, determine prognosis, and suggests the best treatment for the lung cancer patient. Although lung cancer is treatable at any stage, only certain stages can be cured.

In general, a lower stage is associated with better prognosis. However, no doctor can predict how a patient will live with lung cancer based only on the stage of disease, because cancer is different in each person and each patient’s response to treatment is different. The classification system is different for lung cancer small cell and non small cell.

1 .- small cell cancer. It is classified as:

• Disease limited: the tumor has not spread beyond one side of the chest. This region can be treated with radiation. It occurs in about 40% of patients.

• Disease spread: the tumor has spread outside the chest cavity. It is approximately 60% of cases. At present the treatment of choice is chemotherapy.

2 .- Non-Small Cell Cancer: It is classified into several stages depending on its scope:

- Stage 0: there is only disease at the microscopic level. Surgery may completely remove the tumor in this stadium.

- Stage I: there is a single lesion in one lung, and no metastasis or spread of disease to the lymph. The treatment is surgery, and may not be necessary chemotherapy or radiotherapy.
* Stage IA – The tumor is smaller than 3 centimeters, not in a main bronchus and has not spread to any lymph.
* Stage IB – the tumor is in the main bronchus, but does not cause obstruction, it is very close to the trachea, and has not spread to any lymph.

- Stage II: There is a single lesion in one lung, but also extends to nearby lymph nodes. The treatment of choice remains surgery, may be associated also chemotherapy before or after surgery
* Stage IIA – The tumor is smaller than 3 centimeters, not in a main bronchus and has spread to lymph nodes on the same side as the tumor.
* Stage IIB – the tumor is in the main bronchus, not very close to the trachea, does not cause obstruction of the entire lung but has spread to lymph nodes on the same side as the tumor.

- Stage III: the tumor has spread to the mediastinum or the pleura, which may affect different organs found in it, or detect a pleural effusion. Few patients can be operated and at this stage, so generally used chemotherapy and radiation therapy.
*Stage IIIA – further spread to lymph in the phase II (the cancer has spread to lymph nodes in Center of the chest, on the same side where it originated), and has not invaded any vital organs.
* Stage IIIB – the tumor has invaded vital adjacent organs and / or has spread to lymph nodes on the opposite side of the chest, neck lymph specific as scalene, or supraclavicular nodes.

- Stage IV: The cancer has metastasized, ie, has spread to other lung or the bone, brain, liver … The usual treatment is chemotherapy, in order to reduce symptoms and improve the patient’s condition.

In general, cancers of non-small cell lung cancer stage IIIB and IV are generally considered inoperable, so it is very important to find out if cancer has spread to lymph in the opposite side of where the tumor. Part of the monitoring to see if there extension or not the tumor (metastasis) consist of CT (scan) or MRI (magnetic resonance) of the liver, brain, bones and adrenal glands,

Limited Stage
In general, chemotherapy is used as primary treatment, with the use of several drugs in combination.

With chemotherapy is used radiotherapy to the chest. Patients who respond well to initial treatment is administered, so preventive radiation to the head. This is because the brain is one of the sites where metastases frequently occur.

In most patients, these tumors resolve with treatment, but soon reappear becoming resistant to treatment. The survival rate of two years in the limited stage, is 40% to 50% but is reduced by 10% to 20% for five years.

Many studies are underway to test the effectiveness of other treatments such as immunotherapy or gene therapy.

Extensive stage
The prognosis at this stage is very bad if left untreated cancer. Chemotherapy may be used to treat symptoms and flatter short-term survival.

Treatment with two or more drugs can shrink tumors in about 70% to 80% of these patients. Radiation therapy is also used to control symptoms and prevent the occurrence of brain metastases.

Laser surgery is used to relieve airway obstruction in patients who, by their general, not amenable to surgical surgery. The prognosis of survival five years after the discovery of cancer, is younger than 4%.

Patients who have their health badly damaged and can not undergo chemotherapy, your treatment will be reduced to drugs to relieve pain.

Stage 0
At this stage do not require chemotherapy or radiotherapy. Surgery may completely remove the cancer. The type of surgery is a segmentectomy, ie the removal of a lung wedge.

Stage I
Segmentectomy is generally used for smaller tumors or for patients with worse physical condition, or lobectomy to remove the tumor.

The effectiveness of adjuvant chemotherapy, is being tested in clinical trials. Although micrometastases is useful for those that have not been identified and have not been removed by surgery.

If the tumor is at the edge of the lung tissue probably not have removed all the cancer cells, so radiation therapy is recommended.

Radiation therapy can be used as primary treatment if the patient, general condition, can not undergo surgery. The survival rate after five years in this stage is 65%.

Stage II
Used surgery: segmentectomy or lobectomy.

Radiation therapy can be used after surgery to ensure that it is not any cancer cells. It can also be used as primary therapy in those patients who can not be operated on by health problems. Chemotherapy may be used after surgery or radiotherapy.

The survival rate for patients who are in this stage of cancer is 40%.

Stage IIIA
Treatment at this stage will depend on where the tumor is located in the lung and whether lymph nodes are affected.

Chemotherapy is often used before surgery to shrink the tumor, to make it easier to complete removal.

When surgery can not be used to remove the tumor, radiation therapy. It is sometimes used brachytherapy which involves passing a laser through a bronchoscope to destroy part of the cancer within the trachea.

Survival rates range from 10% to 20%, although certain patients such as those with no cancer spread to lymph nodes have a better prognosis.

Stage IIIB
Because at this stage the cancer is widespread, surgery is not effective. Chemotherapy may be used together with radiotherapy. Or each one separately.

The survival rate is between 10% and 20% in those patients who enjoy a good health condition and may undergo a combination of both treatments. Those who can not, its index is 5%.

Stage IV
The aim of treatment at this stage is to alleviate the symptoms of the disease. It is not intended as a cure the cancer has spread to distant sites.

Chemotherapy or radiotherapy is used to reduce symptoms such as bone pain, symptoms due to nervous system, etc..

The classification of small cell lung tumors is much simpler. In this type of cancer is spoken of limited stage and extensive stage.

The limited stage means that the tumor is confined to the hemithorax of origin, the mediastinum and supraclavicular nodes. This would be tolerable in the employment field of radiotherapy.

The extended period is one in which the cancer is too widespread to be included within the definition of limited stage, ie the cancer has spread to other lung, to lymph nodes in the other breast to distant organs, and so on.

Patients with limited stage of cancer may be effectively treated with radiation therapy. In those with extensive stage is not as applicable radiotherapy.

The non-small lung cancers are classified into several stages or phases following a fairly complex system known by the acronym TNM. The staging of the tumor is very important because it can, first, to distinguish patients cured of which are not and, secondly, to calculate the probability of being cured.

The T refers to tumor size. It is classified between T1 and T4, as the more bulky tumor affecting nearby structures or important as the main bronchi, arteries, or the heart itself.

The N indicates whether or not they affected the nearby lymph nodes. N0 means that they are not. The lymph node involvement is an important prognostic factor that graduates from N1 to N3. In particular it is vital to know whether or not invaded most central nodes of the thorax, a region known as the mediastinum. In general, involvement of the mediastinum means the tumor is inoperable.

M indicates if no metastasis (M0) or, conversely, if the cancer has already branched out to distant organs (M1).