Q. What is cancer?
A. The body is made up of many types of cells. Normally, cells grow, divide, and produce more cells as needed to keep the body healthy and functioning properly. Sometimes, however, the process goes wrong -- cells become abnormal and form more cells in an uncontrolled way. These extra cells form a mass of tissue, called a growth or tumor. Tumors can be benign, meaning not cancerous, or malignant, meaning cancerous.
Q. What is lung cancer?
A. Lung cancer occurs when malignant tumors form in the tissue of the lung. The lungs are a pair of sponge-like organs. The right lung has three sections, called lobes, and is larger than the left lung, which has two lobes.
Q. Are there different types of lung cancer?
A. There are two major types of lung cancer -- non-small cell lung cancer and small cell lung cancer. Each type of lung cancer grows and spreads in different ways, and each is treated differently. Non-small cell lung cancer is more common than small cell lung cancer. It generally grows and spreads slowly. Small cell lung cancer, sometimes called oat cell cancer, grows more quickly and is more likely to spread to other organs in the body.
Q. How does smoking affect lung cancer rates?
A. In 1965, about 42 percent of all adults smoked, but by 2008 only 21 percent did. During that time, there has been a sharp drop in lung cancer deaths among men, mainly because fewer men are smoking. Smoking rates, which were dropping, have stopped declining in recent years. Smoking by young people actually increased by 73 percent in the 1990s. Also, more women are getting lung cancer than ever before and more are dying from it, mainly because more young women are smoking. Many smoking education programs now focus on reversing the increase in the number of women and young people who smoke.
Q. What is the main cause of lung cancer?
A. Cigarette smoking is the number one cause of lung cancer. Scientists have reported widely on the link between cancer and smoking since the 1960s. Since then, study after study has provided more proof that cigarette smoking is the primary cause of lung cancer. Before cigarette smoking became popular in the early part of the 20th century, doctors rarely, if ever, saw patients with lung cancer. But today, lung cancer is the leading cause of death by cancer. Nearly 90 percent of people with lung cancer developed it because they smoked cigarettes. Using tobacco products has been shown to cause cancer. In fact, smoking tobacco, using smokeless tobacco, and being exposed regularly to second-hand tobacco smoke are responsible for a large number of cancer deaths in the U.S. each year.
Q. What are the risks of getting lung cancer if you are a smoker?
A. If you smoke cigarettes, you are at much higher risk for lung cancer than a person who has never smoked. The risk of dying from lung cancer is 23 times higher for men who smoke and 13 times higher for women who smoke than for people who have never smoked. Stopping smoking greatly reduces your risk for developing lung cancer. But after you stop, the risk goes down slowly. Ten years after the last cigarette, the risk of dying from lung cancer drops by 50 percent.
Q. Can smoking cigars and pipes lead to lung cancer?
A. Smoking cigars and pipes also puts you at risk for lung cancer. Cigar and pipe smokers have a higher risk of lung cancer than non-smokers. Even cigar and pipe smokers who do not inhale are at increased risk for lung, mouth, and other types of cancer.
Q. Can second-hand smoke cause a non-smoker to get lung cancer?
A. Some studies suggest that non-smokers who are exposed to environmental tobacco smoke, also called secondhand smoke, are at increased risk of lung cancer. Secondhand smoke is the smoke that non-smokers are exposed to when they share air space with someone who is smoking. Each year, about 3,000 non-smoking adults die of lung cancer as a result of breathing secondhand smoke.
Q. Does quitting smoking reduce the risk of other cancers?
A. Quitting smoking not only cuts the risk of lung cancer, it cuts the risks of many other cancers as well as heart disease, stroke, other lung diseases, and other respiratory illnesses.
Q. Can exposure to radon lead to lung cancer?
A. Exposure to radon can put a person at risk for lung cancer, too. People who work in mines may be exposed to this invisible, odorless, and radioactive gas that occurs naturally in soil and rocks. It is also found in houses in some parts of the country. A kit available at most hardware stores allows homeowners to measure radon levels in their homes.
Q. Is there a risk of lung cancer from exposure to asbestos?
A. Another substance that can contribute to lung cancer is asbestos. Asbestos is used in shipbuilding, asbestos mining and manufacturing, insulation work, and brake repair, but many products that contain asbestos have been phased out over the past several decades. If inhaled, asbestos particles can lodge in the lungs, damaging cells and increasing the risk for lung cancer.
Q. What are the possible signs of lung cancer?
A. The possible signs of lung cancer are:
- a cough that doesn't go away and gets worse over time
- constant chest pain
- coughing up blood
- shortness of breath, wheezing, or hoarseness
Q. What are the chances of developing a second lung cancer?
A. A person who has had lung cancer once is more likely to develop a second lung cancer compared to a person who has never had lung cancer. Quitting smoking after lung cancer is diagnosed may prevent the development of a second lung cancer.
Q. How does a doctor usually detect lung cancer?
A. Seeing a spot on a chest x-ray is usually how a doctor first suspects that lung cancer may be present. Doctors may also use imaging methods such as a CT scan or a PET scan to look for signs of cancer. A computeirzed tomography scan, or CT scan, is a series of detailed pictures of areas inside the body. Positron emission tomography, or PET scan, is a computerized image of the metabolic activity of body tissues.
Q. Are there new ways to detect lung cancer before it starts to spread?
A. One screening method that shows promise detecting lung cancer before it has spread is spiral computerized tomography or spiral CT. Spiral CT can scan the lungs from the neck to the diaphragm in less than 20 seconds, or a single breath-hold. Preliminary studies show that it may help doctors find small tumors, but questions remain about the technology's risk and benefits as a screening tool.
In the summer of 2002, the National Cancer Institute launched a $200 million trial called the National Lung Screening Trial to determine if spiral CT is better than conventional x-ray at finding dangerous lung cancers and distinguishing between cancers and non-cancerous changes in the lungs. Most importantly, the study should be able to determine if finding these changes can save lives.
Q. How does a doctor confirm that someone has lung cancer?
A. To confirm that a person has lung cancer, the doctor must examine fluid or tissue from the lung. This is done through a biopsy -- the removal of a small sample of fluid or tissue for examination under a microscope by a pathologist. A biopsy can show whether a person has cancer. A number of procedures may be used to obtain this tissue.
- Bronchoscopy -- The doctor puts a bronchoscope -- a thin, lighted tube -- into the mouth or nose and down through the windpipe to look into the breathing passages. Through this tube, the doctor can collect cells or small samples of tissue.
- Needle Aspiration -- The doctor numbs the chest area and inserts a thin needle into the tumor to remove a sample of tissue.
- Thoracentesis -- Using a needle, the doctor removes a sample of the fluid that surrounds the lungs to check for cancer cells.
- Thoracotomy -- Surgery to open the chest is sometimes needed to diagnose lung cancer. This procedure is a major operation performed in a hospital.
Q. How does a doctor determine how far a lung cancer has progressed?
A. Once lung cancer has been found, it is usually staged. Staging means determining how far the cancer has progressed. Through staging, the doctor can tell if the cancer has spread and, if so, to what parts of the body. Lung cancer often spreads to the brain or bones. Knowing the stage of the disease helps the doctor plan treatment. Small cell lung cancer is divided into two stages. Limited stage is generally cancer confined to the chest and extensive stage is cancer that has spread outside the chest. Non-small cell lung cancer is divided into four stages, I-IV. Most patients with stage I and II non-small cell tumors and some patients with stage III tumors can undergo surgery with the goal of cure. Stage IV denotes cancer that has spread to other sites in the body, most often bone, brain, or liver. Most stage IV cancers cannot be cured, although treatment may be available to help prolong life.
Q. What tests do doctors use to stage lung cancer?
A. Doctors can perform several tests to stage lung cancer. Staging means finding out how far the cancer has progressed. The following tests are used to stage lung cancer:
- Computerized axial tomography or CAT scan is a computer linked to an x-ray machine that creates a series of detailed pictures of areas inside the body.
- Magnetic resonance imaging, or MRI, is a powerful magnet linked to a computer that makes detailed pictures of areas inside the body.
- Radionuclide scanning uses a mildly radioactive substance to show whether cancer has spread to other organs, such as the liver.
- A bone scan uses a small amount of a radioactive substance to show whether cancer has spread to the bones.
- A mediastinoscopy or mediastinotomy can help show whether the cancer has spread to the lymph nodes in the chest by removing a tissue sample. The patient receives a general anesthetic for this procedure.
Q. What are the standard treatments for lung cancer?
- Surgery is an operation to remove the cancer. Depending on the location of the tumor, the surgeon may remove a small part of the lung, a lobe of the lung, or the entire lung.
- Chemotherapy uses anti-cancer drugs to kill cancer cells throughout the body. Doctors use chemotherapy to control cancer growth and relieve symptoms. Anti-cancer drugs are given by injection; through a catheter, a long thin tube temporarily placed in a large vein; or in pill form.
- Radiation therapy uses high-energy beams to kill cancer cells and shrink tumors. An external machine delivers radiation to a limited area, affecting cancer cells only in that area. Doctors may use radiation therapy before surgery to shrink a tumor or after surgery to destroy any cancer cells remaining in the treated area.
- Photodynamic therapy, a newer technique, is laser therapy that is used in combination with a chemical to kill cancer cells. Doctors may use it to reduce symptoms of lung cancer, such as bleeding, or to treat very small tumors.
Q. What are some common ways to treat non-small cell lung cancer?
A. Doctors treat patients with non-small cell lung cancer in several ways, and surgery is a common treatment. Cryosurgery, a treatment that freezes and destroys cancer tissue, may be used to control symptoms in the later stages of non-small cell lung cancer. Doctors may also use radiation therapy and chemotherapy to slow the progress of the disease and to manage symptoms.
Q. What is the best way to treat small cell lung cancer?
A. Small cell lung cancer spreads quickly. In many cases, cancer cells have already spread to other parts of the body when the disease is diagnosed. In order to reach cancer cells throughout the body, doctors almost always use chemotherapy.