How Is Lung Cancer Treated?Thursday, April 19, 2012 - 10:52
The treatment of lung cancer depends on its type and extent. Therefore, the doctor must obtain specific information before suggesting a treatment. The doctor will need to know:
- The type of lung cancer the patient has - whether small-cell lung cancer or non-small-cell lung cancer
- The size of the growth
- Exactly where in the lung it is
- Whether the cancer has spread, and, if so, how far
Obtaining all this information is known as staging the cancer. "Staging" is a method that has been developed to describe the extent of cancer growth. Staging helps to predict:
- How an individual is expected to fare over time
- The chances that the cancer will come back (recur)
Staging allows the physician to customize cancer treatment. In general, the lower the stage the better the person's prognosis (expected outcome).
Lung cancer is "staged" by information that is obtained from the
Tests performed for staging may include:
- CT scan or MRI scan or both. Computerized images are obtained from both of these tests, which allows the lung to be seen in thin slices, clearly showing the extent of any growth within the lung. These tests may also be performed on other parts of the body if there is suspicion that the growth may have spread to other parts of the body.
For more detailed information about MRI scans, go to MRI scan.
For more information about CT scans, go to CT scan.
- Other scanning techniques include various forms of radionuclide scanning and bone scans. These tests can help detect whether the cancer has spread to other organs in the body or to the bones. A low dose of harmless radioactive substance is injected into a vein, and as it travels around the body a specialized scanning machine is able to record radioactivity levels throughout the body. Since the uptake of the radioactive material is different in areas of the body affected by cancer, these areas are readily identified.
- A further specialized test called mediastinoscopy may be offered. This procedure is done while a patient is under general anesthesia. A narrow telescope, to which a camera may be attached, is introduced into the front of the chest through a small incision, or sometimes through a small incision in the neck. A sample of tissue can then be removed from the lymph nodes and other nearby tissue.
Understanding Lung Cancer "Staging"
"Staging" is a method that has been developed to describe the extent of the cancer growth, based on the results of biopsy and other investigations. This information helps to predict how an individual will fare over time. Staging a cancer also allows a physician to customize the cancer treatment to a particular individual.
In lung cancer patients, staging methods are used for non-small-cell lung cancers, which account for about 80% of all cancers.
The TNM cancer staging system is defined as:
- T (for tumor)
- N (for lymph nodes)
- M (for
metastasis, or spread of the cancer)
T refers to the size of the tumor itself:
- TX and T0 - Cancer cells have been found in sputum or lung tissue but cannot be seen.
- Tis - Carcinoma in situ, which means cells are cancerous but the growth does not show evidence of spreading.
- T1 - The tumor is small, still contained in the lung, and has not reached the main airway.
- T2 - The tumor has one or more of the following characteristics: it is larger than 3 cm; it involves the main airway; it is close to the windpipe; it has invaded the membrane covering the lung; it has damaged or inflamed the lung tissue but has not affected the entire lung.
- T3 - The tumor has invaded the chest wall,
diaphragm, membrane covering organs in the chest, or the outer wall of the membrane around the heart, and/or it has affected the entire lung.
- T4 - The tumor has invaded the area between the lungs, heart, major blood vessels of the heart, trachea, esophagus, or spine, and/or separate tumors are present in the same lung lobe, and/or cancer is present in fluid between the membrane covering the lung and the lung (pleural effusion).
N refers to whether the cancer has reached the lymph nodes:
- N0 - Lymph nodes are cancer-free.
- N1 - Cancer has spread to nearest lymph nodes around the airways.
- N2 - Cancer has spread to lymph nodes in the middle of the chest that are adjacent to the affected lung.
- N3 - Cancer has spread to lymph nodes in the middle of the chest that are adjacent to the opposite lung, to lymph nodes in nearby or opposite muscle tissue, or to lymph nodes above the collar bone.
M refers to metastasis, or spread of the cancer:
- M0 - Metastasis has not occurred.
- M1 - Cancer has spread to distant locations within the body.
This information is compiled to determine a staging category for the cancer. In general, the lower the staging category, the better the expected outcome.
- Stage I - The cancer growth is confined to the lung and is surrounded by normal lung tissue.
- Stage II - The cancer has spread to the nearby lymph nodes (these are structures that drain lymph fluid from the lungs).
- Stage III - The cancer has now spread outside of the lung, to the chest wall or to the diaphragm muscle beneath the lungs, or to the lymph nodes on the other side of the chest, or to the lymph nodes in the neck. Stage III is divided into Stage IIIa, implying that the cancer may still be removed by surgery, and Stage IIIb, in which the cancer cannot be removed by surgery.
- Stage IV - The cancer has broken away from the original cancer growth and has spread beyond the lungs to other parts of the body. This is known as metastasis of the cancer.
The treatment of lung cancer will usually consist of a combination of therapies, rather than a single therapy, which may result in a better outcome. The different treatment modalities include:
- Chemotherapy. This involves the use of medications that are able to kill cancer cells. Chemotherapy may be selected as the major treatment to kill the cancer cells, or as a treatment to kill any remaining cancer cells either alone or in conbination with surgical removal of the tumor. It also can be used to treat a cancer growth elsewhere in the body.
Chemotherapy drugs are mainly given through a catheter, which is a thin tube that is placed into a large vein. The catheter may be left in place for the duration of the treatment or removed after each treatment session. A number of chemotherapy drugs are available as a pill.
- Radiation therapy. Radiation therapy involves the use of high-dose x-rays to destroy the cancer cells or make the growths smaller. It is also used after surgery to destroy any remaining cancer cells. Radiation therapy can be directed precisely to those areas in the body to where cancer has spread, such as the bones, brain, or spine.
For more detailed information about radiation therapy, go to Radiation Therapy.
- Surgery. Depending on the "stage" of the cancer, a number of surgical options are available. A wedge resection involves removing a small part of the lung in which the growth is located. Alternatively, a whole lobe of the lung may be removed, in a procedure is known as a lobectomy. On occasions, it may be necessary to remove the entire lung; this procedure is called a pneumonectomy. A new type of less invasive surgery - video assisted thoracoscopic surgery or VATS - has been introduced to remove tumors which are near the outer edges of the lung. Usually 3 small incisions instead of one large incision are made with this type of surgery and recovery is faster.
- Photodynamic therapy. Photodynamic therapy is a newer treatment, used more often during clinical trials. Photodynamic therapy is used only for tumors in the main central airways that either recur after surgery or chemotherapy or, because of their location and/or size, are not amenable to surgery. It involves the use of a laser light aimed at the cancerous growth, which activates a chemical that has been injected into the blood stream and is absorbed and held for a period of time by cancer cells (while normal cells release the chemical quickly). The chemical, activated by the laser, then kills the cancer cells.
- Other experimental therapies. This includes immunotherapy, which uses drugs to boost a person's immune system to fight cancer. It also includes gene therapy, which involves methods to attack genetic mutations that are causing the cancer. Under investigation are angiogenesis inhibitors, which are agents that inhibit the formation of new blood vessels that are critical to the spread of cancer.
Need To Know:
The treatments for lung cancer often do not cure the disease. How successful the treatment will be depends on the type and staging of the lung cancer.
Clinical trials are always underway to test new drugs and try new ways to offer these types of treatments. A clinical trial is a research study to determine the effectiveness of newer treatments.
For more information about clinical trials for lung cancer, contact the National Cancer Institute's Cancer Information Service at 1-800-4-CANCER (800-422-6237) or go to http://cancertrials.nci.nih.gov.