Lung Cancer - OnCare Cancer Center Lung Cancer Intruduction

What is lung cancer?

Cancer of the lung, like all cancers, results from an abnormality in the body's basic unit of life, the cell. Normally, the body maintains a system of checks and balances on cell growth so that cells divide to produce new cells only when new cells are needed. Disruption of this system of checks and balances on cell growth results in an uncontrolled division and proliferation of cells that eventually forms a mass known as a tumor.

Symptoms and signs:

You should consult a doctor if you develop the symptoms associated with lung cancer, in particular, if you have

  • a new persistent cough or worsening of an existing chronic cough
  • blood in the sputum,
  • persistent bronchitis or repeated respiratory infections
  • chest pain
  • unexplained weight loss and/or fatigue
  • breathing difficulties such as shortness of breath or wheezing.

Types:

Adenocarcinomas are the most commonly seen type of NSCLC in the U.S. and comprise up to 50% of NSCLC. While adenocarcinomas are associated with smoking, like other lung cancers, this type is observed as well in nonsmokers who develop lung cancer. Most adenocarcinomas arise in the outer, or peripheral, areas of the lungs.

  • Bronchioloalveolar carcinoma is a subtype of adenocarcinoma that frequently develops at multiple sites in the lungs and spreads along the preexisting alveolar walls.
  • Squamous cell carcinomas were formerly more common than adenocarcinomas; at present, they account for about 30% of NSCLC. Also known as epidermoid carcinomas, squamous cell cancers arise most frequently in the central chest area in the bronchi.
  • Large cell carcinomas, sometimes referred to as undifferentiated carcinomas, are the least common type of NSCLC.
  • Mixtures of different types of NSCLC are also seen.

Other types of cancers can arise in the lung; these types are much less common than NSCLC and SCLC and together comprise only 5%-10% of lung cancers:

Bronchial carcinoids account for up to 5% of lung cancers. These tumors are generally small (3 cm-4 cm or less) when diagnosed and occur most commonly in people under 40 years of age. Unrelated to cigarette smoking, carcinoid tumors can metastasize, and a small proportion of these tumors secrete hormone-like substances that may cause specific symptoms related to the hormone being produced. Carcinoids generally grow and spread more slowly than bronchogenic cancers, and many are detected early enough to be amenable to surgical resection.

Diagnostic tests:

You may be given one or more of the following tests.

Chest X-ray
Since lung cancer can usually be seen on the X-ray film, a chest X-ray is one of the first tests you will have. As with most types of X-ray pictures, a chest X-ray causes no discomfort.

The smallest tumor that can be seen on a chest X-ray is about 1/2-inch in diameter. But even if a tumor is not seen, the chest X-ray may offer other clues to the diagnosis, such as pneumonia in the lung. Other possible clues are enlarged lymph nodes (which may be filled with cancer cells), and pleural effusion, an accumulation of fluid in the space between the lung and the chest wall. Lung cancer is not always the cause of these, but they are signs that alert the doctor to look for the cause, using other diagnostic tools.

Your doctor may want you to have a chest X-ray even if the diagnosis is already clear. The purpose is to be able to compare it with previous and later X-rays, to follow your progress and watch for possible changes in the lung tissue. It is important for your doctor to find out whether the cancer is growing, or whether it is responding to treatment and shrinking.

CAT scan (also called CT scan)
Patients with suspected lung cancer will almost always have a CAT (computerized axial tomography) scan of the chest and upper abdomen to help in diagnosis and staging. Other areas such as the head or back may be scanned if worrisome symptoms are present.

A CAT scan is a type of X-ray study combined with computer processing to provide a much more detailed picture of the lymph nodes and blood vessels in your lungs and chest than an ordinary chest X-ray can. Your doctor will be able to make a more exact evaluation of the size and extent of the tumor, the presence of enlarged lymph nodes, and whether bones or vital structures and organs are involved.

To allow a better picture, dye will probably be injected into a vein in your arm. Be sure to inform your doctor if you have ever had an allergy to X-ray dye or to seafood. Aside from the needle stick for the dye, a CAT scan is painless. The X-ray machine will move around you and you will be asked to hold your breath for several seconds as pictures are taken.

MRI (magnetic resonance imaging)
With this technique, detailed pictures of various organs are obtained using a magnetic field. It is painless, but may involve lying in a confined space for up to 30 minutes. If you think that being in an enclosed space may make you uncomfortable or anxious, ask about receiving a mild tranquilizer before the test. (Some newer MRI machines are more open.) The MRI is usually used for brain imaging when headache is one of the symptoms. It may also be used to evaluate blood vessel or bone involvement of a lung tumor, when this information is not clear on the CAT scan.

Sputum cytology
You may be asked for a sputum sample, so it can be examined under the microscope for the presence of cancer cells. In this way, the diagnosis of lung cancer and its specific cell type can sometimes be made without the need for more invasive testing. If you are unable to cough up a deep sputum sample, you may be given a mist of moisturized air to inhale, to stimulate sputum production.

Bronchoscopy
A flexible lighted tube called a fiberoptic bronchoscope is used to examine the airways, to see the tumor. The doctor needs to learn its type and exact location. This information is important for deciding whether surgery will be possible. If the tumor is not visible, an X-ray can help localize it so that the doctor can obtain biopsies through the bronchoscope.

Bronchoscopy is usually an outpatient procedure. You will be asked to arrive with an empty stomach and to bring a friend or relative who will be able to drive you home.

You may be given one or more of the following tests.

Chest X-ray

Since lung cancer can usually be seen on the X-ray film, a chest X-ray is one of the first tests you will have. As with most types of X-ray pictures, a chest X-ray causes no discomfort.

The smallest tumor that can be seen on a chest X-ray is about 1/2-inch in diameter. But even if a tumor is not seen, the chest X-ray may offer other clues to the diagnosis, such as pneumonia in the lung. Other possible clues are enlarged lymph nodes (which may be filled with cancer cells), and pleural effusion, an accumulation of fluid in the space between the lung and the chest wall. Lung cancer is not always the cause of these, but they are signs that alert the doctor to look for the cause, using other diagnostic tools.

Your doctor may want you to have a chest X-ray even if the diagnosis is already clear. The purpose is to be able to compare it with previous and later X-rays, to follow your progress and watch for possible changes in the lung tissue. It is important for your doctor to find out whether the cancer is growing, or whether it is responding to treatment and shrinking.

CAT scan (also called CT scan)

Patients with suspected lung cancer will almost always have a CAT (computerized axial tomography) scan of the chest and upper abdomen to help in diagnosis and staging. Other areas such as the head or back may be scanned if worrisome symptoms are present.

A CAT scan is a type of X-ray study combined with computer processing to provide a much more detailed picture of the lymph nodes and blood vessels in your lungs and chest than an ordinary chest X-ray can. Your doctor will be able to make a more exact evaluation of the size and extent of the tumor, the presence of enlarged lymph nodes, and whether bones or vital structures and organs are involved.

To allow a better picture, dye will probably be injected into a vein in your arm. Be sure to inform your doctor if you have ever had an allergy to X-ray dye or to seafood. Aside from the needle stick for the dye, a CAT scan is painless. The X-ray machine will move around you and you will be asked to hold your breath for several seconds as pictures are taken.

MRI (magnetic resonance imaging)

With this technique, detailed pictures of various organs are obtained using a magnetic field. It is painless, but may involve lying in a confined space for up to 30 minutes. If you think that being in an enclosed space may make you uncomfortable or anxious, ask about receiving a mild tranquilizer before the test. (Some newer MRI machines are more open.) The MRI is usually used for brain imaging when headache is one of the symptoms. It may also be used to evaluate blood vessel or bone involvement of a lung tumor, when this information is not clear on the CAT scan.

Sputum cytology

You may be asked for a sputum sample, so it can be examined under the microscope for the presence of cancer cells. In this way, the diagnosis of lung cancer and its specific cell type can sometimes be made without the need for more invasive testing. If you are unable to cough up a deep sputum sample, you may be given a mist of moisturized air to inhale, to stimulate sputum production.

Bronchoscopy

A flexible lighted tube called a fiberoptic bronchoscope is used to examine the airways, to see the tumor. The doctor needs to learn its type and exact location. This information is important for deciding whether surgery will be possible. If the tumor is not visible, an X-ray can help localize it so that the doctor can obtain biopsies through the bronchoscope.

Bronchoscopy is usually an outpatient procedure. You will be asked to arrive with an empty stomach and to bring a friend or relative who will be able to drive you home.

Treatment:

The three options for treating lung cancer—surgery, chemotherapy, and radiation therapy—may be used alone or in combination. The choice of treatment depends on a number of factors, including the size and location of the tumor, whether the cancer is small cell or non-small cell, the physical condition of the person who is being treated, and whether the cancer has spread to or beyond the lymph nodes.

Surgery

The surgical procedure chosen depends upon the size and location of the tumor. Surgeons must open the chest wall and may perform a wedge resection of the lung (removal of a portion of one lobe), a lobectomy (removal of one lobe), or a pneumonectomy (removal of an entire lung). Sometimes lymph nodes in the region of the lungs also are removed (lymphadenectomy). Surgery for lung cancer is a major surgical procedure that requires general anesthesia, hospitalization, and follow-up care for weeks to months. Following the surgical procedure, patients may experience difficulty breathing, shortness of breath, pain, and weakness. The risks of surgery include complications due to bleeding, infection, and complications of general anesthesia.

Radiation

Radiation therapy may be employed as a treatment for both NSCLC and SCLC. Radiation therapy uses high-energy X-rays or other types of radiation to kill dividing cancer cells. Radiation therapy may be given as curative therapy, palliative therapy (using lower doses of radiation than with curative therapy), or as adjuvant therapy in combination with surgery or chemotherapy. The radiation is either delivered externally, by using a machine that directs radiation toward the cancer, or internally through placement of radioactive substances in sealed containers within the area of the body where the tumor is localized. Brachytherapy is a term used to describe the use of a small pellet of radioactive material placed directly into the cancer or into the airway next to the cancer. This is usually done through a bronchoscope.

Chemotherapy

Both NSCLC and SCLC may be treated with chemotherapy. Chemotherapy refers to the administration of drugs that stop the growth of cancer cells by killing them or preventing them from dividing. Chemotherapy may be given alone, as an adjuvant to surgical therapy, or in combination with radiotherapy. While a number of chemotherapeutic drugs have been developed, the class of drugs known as the platinum-based drugs have been the most effective in treatment of lung cancers.

Chemotherapy is the treatment of choice for most SCLC, since these tumors are generally widespread in the body when they are diagnosed. Only half of people who have SCLC survive for four months without chemotherapy. With chemotherapy, their survival time is increased up to four- to fivefold. Chemotherapy alone is not particularly effective in treating NSCLC, but when NSCLC has metastasized, it can prolong survival in many cases.

Chemotherapy may be given as pills, as an intravenous infusion, or as a combination of the two. Chemotherapy treatments usually are given in an outpatient setting. A combination of drugs is given in a series of treatments, called cycles, over a period of weeks to months, with breaks in between cycles. Unfortunately, the drugs used in chemotherapy also kill normally dividing cells in the body, resulting in unpleasant side effects. Damage to blood cells can result in increased susceptibility to infections and difficulties with blood clotting (bleeding or bruising easily). Other side effects include fatigue, weight loss, hair loss, nausea, vomiting, diarrhea, and mouth sores. The side effects of chemotherapy vary according to the dosage and combination of drugs used and may also vary from individual to individual. Medications have been developed that can treat or prevent many of the side effects of chemotherapy. The side effects generally disappear during the recovery phase of the treatment or after its completion.

Targeted Therapy

New medical treatments called targeted therapies are becoming available for lung cancer. Unlike traditional chemotherapy, these treatments target proteins on cancer cells or target normal cells that have been hijacked by the tumor in its attempts to grow. For that reason they tend to have fewer side effects that many of the medications used for cancer. Currently, these are used primarily for stage 3 and 4 lung cancer that has not responded to other treatments.

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