Lung cancer now is the most common cancer-related cause of death among men and women. In 2002 there will be about 169,400 new cases of lung cancer in the U.S, among which, 154,900 will die, including 89,200 men and 65,700 women.
The lungs, two sponge-like organs in your chest, work along with your ribs and chest muscles to bring air in and out of your body. Air is drawn in through your nose or mouth, down through your trachea, or windpipe, and then into your bronchi, the tubes that go into each lung. In your lungs, the bronchi divide further into bronchioles, which end in tiny balloon-like sacs called alveoli. These sacs are found throughout your lungs and are the places where oxygen from the air is exchanged for the waste product carbon dioxide, which you exhale.
Each lung is composed of sections called lobes. Your right lung has three lobes, while the left has two, leaving more room on that side for the heart. Lung cancer can begin in the alveoli, bronchioles, or trachea, but it most often starts in the bronchi.
Diagnosis
Lung cancer is difficult to detect early because symptoms usually do not appear until the disease is advanced. Symptoms depend on the location of the tumor and can include persistent cough, hoarseness or wheezing, shortness of breath, sputum streaked with blood, recurring bronchitis or pneumonia, weight loss and loss of appetite, and chest pain.
Physicians use several techniques to diagnose lung cancer. Chest x-rays and CT (computed tomography) scans help locate abnormal areas in the lung. A new technique called spiral CT may offer a novel approach for screening for the disease. A sputum sample can also be analyzed for the presence of cancerous cells. Doctors may perform a bronchoscopy, which allows them to examine the bronchial passages using an instrument called a bronchoscope. This is a small tube that is inserted through the nose or mouth, down the throat and into the bronchi. During the procedure physicians may remove some tissue for analysis. To examine areas of the lungs that are not accessible during a bronchoscopy, physicians may perform a needle biopsy to remove a small sample of tissue for analysis.
Types of Lung Cancer
There are two major types of lung cancer: small cell and non-small cell. They each affect different types of cells in the lung and grow and spread in a different ways, so doctors treat them differently. A diagnosis will include not only the type of lung cancer but the stage, which describes the extent and spread of the disease at diagnosis.
Non-small-cell lung cancer, the most common type of lung cancer, is usually associated with a history of smoking, passive smoking, or exposure to radon. It can be further divided into three categories named for the type of cell found in the tumor: squamous cell carcinoma (also called epidermoid carcinoma), adenocarcinoma, and large cell carcinoma. Non-small-cell lung cancer is described using four stages. In stage one the cancer is confined to the lung; in stages two and three the cancer is confined to the chest; and in stage four the cancer has spread from the chest.
Small-cell lung cancer, also called oat cell lung cancer, accounts for a quarter of all lung-cancer cases and is associated with a history of smoking. The extent of the disease is described using a two-stage system. A case can be limited, meaning the cancer is confined to a portion of the chest, or extensive, meaning the cancer has spread throughout or from the chest.
Tumors found in the lungs sometimes originate in cancer elsewhere in the body. In these cases, treatment will be different from that for cancer that originates in the lungs.
Orthodox Treatment
Lung cancer can be treated with surgery, chemotherapy, radiation, or a combination of these modalities, depending on the type and stage of the disease. For non-small-cell lung cancers that have not spread beyond the lung, surgery is most often used. Over the past several years, surgical techniques for treating lung cancer have improved greatly. When the disease has spread, treatment will often include radiation therapy and chemotherapy. For small-cell lung cancer, chemotherapy, often combined with radiation therapy, is now the most common treatment. Radiation therapy is also sometimes used in both forms of lung cancer to relieve pain and bleeding and alleviate problems with swallowing.
How non-small cell lung cancer is treated
Chemotherapy uses drugs to kill cancer cells. Chemotherapy may be taken by pill, or it may be put into the body by a needle in the vein or muscle. Chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body, and can kill cancer cells outside the lungs.
Chemoprevention uses drugs to prevent a second cancer from occurring.
Radiation therapy uses high-energy x-rays to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external radiation therapy) or from putting materials that produce radiation (radioisotopes) through thin plastic tubes in the area where the cancer cells are found (internal radiation therapy).
One new type of radiation therapy is called radiosurgery. In radiosurgery, radiation is directly focused on the tumor, and involves as little normal tissue as possible. Radiosurgery is usually used as treatment of tumors that involve the brain.
Cryosurgery freezes the tumor and kills it. Photodynamic therapy uses a certain type of light and a special chemical to kill cancer cells. Laser therapy uses a narrow beam of light to kill cancer cells. Cryosurgery and photodynamic therapy are usually used in clinical trials.
Surgery, radiation therapy, and chemotherapy are used to treat non-small cell lung cancer. However, these treatments often do not cure the disease.
If lung cancer is found, a patient may want to think about taking part in one of the many clinical trials being done to improve treatment. Clinical trials are ongoing in most parts of the country for all stages of non-small cell lung cancer. Treatment choices can be discussed with a doctor.
Patients with non-small cell lung cancer can be divided into three groups, depending on the stage of the cancer and the treatment that is planned. The first group (stages 0, I, and II) includes patients whose cancers can be taken out by surgery. The operation that takes out only a small part of the lung is called a wedge resection. When a whole section (lobe) of the lung is taken out, the operation is called a lobectomy. When one whole lung is taken out, it is called a pneumonectomy.
Radiation therapy may be used to treat patients in this group who cannot have surgery because they have other medical problems. Like surgery, radiation therapy is called local treatment because it works only on the cells in the area being treated.
The second group of patients has lung cancer that has spread to nearby tissue or to lymph nodes. These patients can be treated with radiation therapy alone or with surgery and radiation, chemotherapy and radiation, or chemotherapy alone.
The third group of patients has lung cancer that has spread to other parts of the body. Radiation therapy may be used to shrink the cancer and to relieve pain. Chemotherapy may be used to treat some patients in this group.
How small cell lung cancer is treated
There are treatments for all patients with small cell lung cancer. Three kinds of treatment are used: surgery, radiation therapy and chemotherapy.
Additionally, clinical trials are testing the effect of new therapies on the treatment of small cell lung cancer.
Surgery may be used if the cancer is found only in one lung and in nearby lymph nodes. Because this type of lung cancer is usually not found in only one lung, surgery alone is not often used. Occasionally, surgery may be used to help determine exactly which type of lung cancer the patient has. If a patient does have surgery, the doctor may take out the cancer in one of the following operations:
- Wedge resection removes only a small part of the lung.
- Lobectomy removes an entire section (lobe) of the lung.
- Pneumonectomy removes the entire lung.
During surgery, the doctor will also take out lymph nodes to see if they contain cancer.
Radiation therapy uses x-rays or other high-energy rays to kill cancer cells and shrink tumors. Radiation therapy for small cell lung cancer usually comes from a machine outside the body (external beam radiation therapy). It may be used to kill cancer cells in the lungs or in other parts of the body where the cancer has spread. Radiation therapy may also be used to prevent the cancer from growing in the brain. This is called prophylactic cranial irradiation (PCI). Because PCI may affect brain function, the doctor will help the patient decide whether to have this kind of radiation therapy. Radiation therapy can be used alone or in addition to surgery and/or chemotherapy.
Chemotherapy is the most common treatment of all stages of small cell lung cancer. Chemotherapy may be taken by pill, or it may be put into the body by a needle in the vein or muscle. Chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body, and can kill cancer cells outside the lungs, including cancer cells that have spread to the brain.
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