| What is lung cancer? |
Lung cancer is the leading cause of cancer deaths in the United States, among both men and women. It claims more lives than colon, prostate and breast cancer combined. The American Cancer Society estimates annual lung cancer deaths in the United States at about 89,200 men and 65,700 women.
Yet lung cancer is also among the most preventable of all cancers. Smoking alone accounts for about 85 percent to 90 percent of lung cancer cases. Other leading causes include exposure to radon, asbestos and secondhand smoke.
Although the mortality rate from lung cancer has been declining for men, the rate for women has increased. One reason may be that although smoking rates have decreased overall, the rate has decreased more rapidly for men. But new cases of lung cancer in women have been declining, which means that their mortality rate is likely to decline in the future.
Lung cancer may be divided into two groups: small cell and non-small cell. Small cell lung cancer spreads aggressively and occurs almost exclusively in smokers. In the United States it accounts for about 20 percent of lung cancers. Non-small cell lung cancer, which is more common, accounts for almost 80 percent of lung cancers. There are three major categories of non-small cell lung cancer:
- Squamous cell carcinoma. This cancer forms in cells lining your airways. It’s the most common type of lung cancer in men.
- Adenocarcinoma. This type of cancer usually begins in the mucous-producing cells of the lung. It's the most common type of lung cancer in women and people who have never smoked.
- Large cell carcinoma. This type of cancer originates in the peripheral part of the lungs.
|
| Signs and symptoms |
Unfortunately, lung cancer has no symptoms in its earliest stages. By the time most people with lung cancer see a doctor, the condition has reached an advanced stage. The most common symptom is a cough, which occurs when a tumor irritates the lining of the airways or blocks the passage of air. In addition to a new cough, be alert to the following:
- "Smoker’s cough" that worsens
- Coughing up blood, even a small amount
- Chest pain
- Shortness of breath
- New onset of wheezing
- Repeated bouts of pneumonia or bronchitis
- Hoarseness that lasts more than 2 weeks
Although many of these symptoms might be attributed to other causes, inform your doctor if you experience such problems. The earlier you discover and treat lung cancer, the better chance you have of lengthening your life and reducing symptoms.
|
| Causes |
Healthy cells grow and divide to keep your body functioning normally. But sometimes this growth gets out of control — cells continue reproducing even when new cells aren’t needed.
In the lungs, these abnormal cells primarily originate when the lungs are exposed to cancer-causing substances (carcinogens), such as those found in cigarette smoke, radon and asbestos.
At first only a small number of abnormal cells (precancerous lesions) may appear, but with repeated exposure to carcinogens over a number of years, these cells increase and eventually become cancerous (malignant).
Cancer cells in the lungs have easy access to a large number of blood and lymph vessels. Tumors can invade these vessels, which may carry cancerous cells to nearby sites and even to remote areas and organs within the body (metastasis).
Cigarette smoking accounts for 85 percent to 90 percent of all lung cancers. Other risk factors for lung cancer include exposure to asbestos and other industrial carcinogens, secondhand smoke and high concentrations of radon — an odorless gas that’s released into the air from the breakdown of uranium in the soil and water.
Primary lung cancer is uncommon in nonsmokers, but cancer of the breast, colon, prostate, testicle, kidney, thyroid, bone or other organs may spread (metastasize) to the lungs. In that case, however, the cancer is still referred to by the name of the organ in which it originated, rather than being called lung cancer.
| Risk factors |
Smoking remains the greatest risk factor for lung cancer. Studies have shown that as many as 9 out of 10 cases of lung cancer are caused by smoking. Your risk increases with the number of cigarettes you smoke each day, the number of years you have smoked, and the earlier the age at which you started smoking. Even daily exposure to secondhand smoke may increase your chances of developing lung cancer by as much as 30 percent.
In addition, several studies have reported that women smokers — current or former — are at greater risk of developing lung cancer than men who've smoked an equal amount. The studies indicate that women who smoke may be at a 1.5- to 2-fold greater risk than men who smoke. This increased risk may indicate that women have a greater susceptibility to the cancer-causing substances found in tobacco.
The good news is, it's never too late to quit smoking. Research has shown that quitting — at any age — can significantly lower your risk of developing lung cancer. A study presented in the Aug. 5, 2000, British Medical Journal reported that smokers who quit for less than 10 years lowered their risk of lung cancer by one-third. And those who quit for more than 30 years lowered their risk to 10 percent.
The second highest risk factor for lung cancer is exposure to radon gas. Radon comes from the natural (radioactive) breakdown of uranium in soil, rock and water that eventually becomes part of the air you breathe. Although unsafe levels of radon can accumulate in any building, the greatest exposure risk most people face is at home, so it’s important to test for presence of the gas. The best tests for radon are longer-term tests that take 3 to 6 months.
Workplace exposure to asbestos and other cancer-causing agents — such as vinyl chloride, nickel chromates and coal products — also can put you at a higher risk of developing lung cancer, especially if you’re a smoker.
|
| Screening and diagnosis |
The American Cancer Society currently doesn't recommend screening tests for lung cancer, even in high-risk individuals. Some doctors believe that smokers, especially those 50 years or older, should have an annual chest X-ray, although having annual chest X-rays has never been shown to extend how long people live.
A study reported in the March 2003 issue of Radiology found that a certain type of computerized tomography (CT) scan for people at high risk of lung cancer may be able to detect lung cancer when it's at a much smaller size and at a much earlier stage of development — when the chance of survival is greater. However, the type of imaging — called a spiral CT scan — also has serious drawbacks. Spiral CT scanning is a faster method of CT scanning that provides a more detailed image. In the study 1,049 of the 1,520 people screened had lumps called uncalcified lung nodules. These people needed to undergo the further expense, stress and risk — including surgery — of additional testing. More than 95 percent of the people went through the extra testing only to find out they didn't have lung cancer. Instead, their nodules were noncancerous (benign). One author of the study said that more research is needed to determine if early CT scans would do more harm than good. If you're at high risk for lung cancer and you're interested in screening, check to see if you're eligible to participate in the National Lung Screening Trial, sponsored by the National Cancer Institute. The Web address is http://www.nci.nih.gov/NLST.
In addition, results of a study that appeared in a 2001 issue of Cancer Research show that smokers with high levels of certain compounds in their blood are much more likely to develop lung cancer than smokers with lower levels of the compounds. Researchers who conducted the study say that a simple blood test may one day help identify smokers at high risk of lung cancer, although no such test currently exists.
Diagnosis
At the diagnosis stage, an X-ray or a CT scan can allow your doctor to view the extent of lung cancer. An X-ray may reveal an abnormal nodule or mass in your lungs, while a CT scan can show more details and may reveal very small lesions and whether the cancer has spread to other areas.
Doctors can make a diagnosis of cancer with certainty only by looking at tissue under a microscope. Taking a tissue sample (biopsy) is done by one of several methods:
- Bronchoscopy. Using a flexible tube (fiber-optic bronchoscope) passed down your airway, your doctor can look inside your lungs and take a tissue sample for examination in the laboratory.
- Mediastinoscopy. While you are asleep under anesthesia, an instrument passed through a small incision at the base of your neck allows doctors to take a biopsy of lymph nodes in your chest. This permits a surgeon to define the extent of the tumor (stage) and determine whether it's reasonable to attempt surgery to remove the tumor (resection).
- Transthoracic needle biopsy. Using an X-ray or CT scan for guidance, your doctor takes a small needle and places it into a mass in your lung, removing a small piece for study.
- Sputum cytology. If you have a cough and are producing sputum, sometimes looking at the sputum under the microscope can reveal the presence of lung cancer cells.
- Thoracentesis. If fluid is present in your chest cavity, your doctor can remove a sample by inserting a thin needle into your chest between the ribs. This fluid can then be examined in the laboratory for presence of cancer cells. If you have a large amount of fluid in your chest cavity, this procedure can also remove enough fluid to temporarily improve breathing.
- Video thoracoscopy. In this procedure, your doctor inserts a tube (endoscope) through a small incision to collapse one of your lungs. This creates a space through which a pen-sized instrument with a video device may enter your chest wall. Your doctor then can perform biopsies of nodules or masses while watching the procedure on a video screen.
Staging
Staging refers to determining the extent of spread of the cancer. Your doctor will use X-rays, scans and blood tests to determine exactly where the cancer is. This helps to choose the most appropriate treatment and project the outlook for recovery.
Small cell lung cancer is staged as either limited or extensive:
- Limited. Cancer is confined to one lung and to its neighboring lymph nodes.
- Extensive. Cancer has spread beyond one lung and its neighboring lymph nodes, possibly invading both lungs, more remote lymph nodes or other organs.
- Stage 0. The cancer is limited to the lining of air passages and hasn't invaded lung tissue. The cancer can usually be eliminated when caught and treated.
- Stage I. The cancer has spread to layers of lung tissue but has not reached the lymph nodes or beyond. There is a 60 percent to 80 percent chance of surviving the disease 5 years when it's caught and treated at this stage.
- Stage II. The cancer has invaded neighboring lymph nodes or spread to the chest wall. There is a 40 percent to 50 percent chance of surviving the disease 5 years when it’s caught and treated at this stage.
- Stage IIIA. The cancer has spread from the lung to lymph nodes beyond the lung area. Cancer usually isn't treated surgically at this stage. There is a 15 percent to 30 percent chance of surviving 5 years when the disease is caught and treated with radiation or chemotherapy at this point.
- Stage IIIB. The cancer has spread to areas such as the heart, blood vessels, trachea and esophagus — all within the chest. Cancer can't be treated surgically at this stage. A 10 percent to 15 percent chance of surviving 5 years exists when the disease is treated at this point.
- Stage IV. The cancer has spread to other parts of the body, such as the liver, bones or brain. There is less than a 2 percent chance of surviving the disease 5 years when it's treated at this stage.
| Complications |
Your lungs are abundantly supplied with blood and lymph — a fluid that helps to return water and proteins from your tissues to your blood. Lung cancer spreads easily to other parts of your body through your bloodstream and lymph system.
Small cell cancer is a fast-growing tumor that quickly spreads to other organs. At the time of diagnosis, this type of cancer will have already spread (metastasized) in over two-thirds of people with the condition. Without treatment the tumor will grow, leading to death within several months. Even with treatment and apparent response, relapses usually occur within 2 years, and then the cancer usually isn’t responsive to further chemotherapy or radiation therapy.
| Treatment |
After diagnosis, treatment of lung cancer depends on the size, location (stage) and type of cancer, as well as on your overall health. The average length of survival after treatment also depends on the stage of the cancer, the cell type and your response to treatment.
Small cell lung cancer
An operation generally isn't a treatment option for small cell lung cancers because almost all have metastasized by the time they're discovered. The most effective treatment is chemotherapy, either alone or in combination with radiation therapy. The exact treatment depends on the extent of the cancer (limited or extensive stage).
The standard chemotherapy for small cell lung cancer is etoposide (VePesid) with cisplatin (Platinol) or carboplatin (Paraplatin), and people generally receive four to six treatment cycles. Additionally, there are some newer chemotherapeutic agents, such as paclitaxel (Taxol) and topotecan (Hycamtin) that are currently being evaluated to determine their optimal role.
Non-small cell lung cancer
For non-small cell lung cancers confined to a limited area, surgical removal is usually the initial treatment of choice. Three types of operations involve removal of lung tissue:
- Wedge resection is removal of only a small section of the lung that contains the tumor.
- Lobectomy entails removal of an entire lobe of one lung. Your right lung has three lobes, and your left lung has two. Lobectomy is the most common type of lung cancer surgery.
- Pneumonectomy involves removal of an entire lung.
After having surgery to remove lung tissue, you can expect, on average, a 1-week hospital stay and a month or more of avoiding strenuous activity. In addition, because surgeons have to cut between your ribs to get to your lungs, you may experience pain in your ribs until they fully heal.
If you have other chronic lung conditions, such as emphysema or bronchitis, it's possible that you might encounter more prolonged hospitalization from complications as well as long-term shortness of breath. In addition, having severe COPD or emphysema may put you at too great a risk for surgical treatment, even if your cancer is operable.
More advanced non-small cell lung cancers are generally treated with chemotherapy alone, or a combination of chemotherapy and radiation therapy. Using combination therapy depends on your physical condition and the stage of the disease.
There is no standard chemotherapy for non-small cell lung cancer. Typical chemotherapy drugs used to treat non-small cell lung cancer include a cisplatin- or carboplatin-based regimen. The most commonly used combination therapies include paclitaxel and carboplatin, gemcitabine hydrochloride (Gemzar) and cisplatin, and vinorelbine (Navelbine) and cisplatin. Other treatments may be equally effective, but may only be available in clinical trials. Active research to discover new and more effective therapy is ongoing.
Advances in computerized tomography imaging techniques have provided radiation oncologists with a more precise means of locating tumors. This helps them to administer radiation treatments from multiple angles with a maximum dose to the tumor while minimizing damage to surrounding tissue. Radiation treatments may be administered before, with or after chemotherapy treatments.
In people with stage IIIA or IIIB disease, chest radiation is generally combined with systemic chemotherapy. Recent studies have suggested that concurrent treatment is more effective than sequential treatment.
Early detection and treatment make a difference. Nearly half of all people with lung cancer whose tumors are detected early — before spreading beyond the lungs — live 5 or more years after diagnosis and treatment. Among all people with lung cancer, only about 14 percent of people live 5 years after diagnosis.
|
| Self-care |
One of the best things you can to do to care for yourself if you have lung cancer is also one of the most obvious — don't smoke. It’s best to also avoid being around people who are smoking. Although it may be too late to prevent developing lung cancer, this will help optimize your lung function while you are being treated and improve your tolerance to treatment that may have some effects on your lungs.
Regular exercise, such as walking, exercise bicycling or swimming, will help you to maintain your general strength and stamina. Twenty to 30 minutes of exercise at least four to five times a week will provide the most benefit.
In addition, eating well and managing stress are both ways to promote your overall health and cope with any form of cancer. Eating well during cancer treatment can help you maintain your stamina and better cope with chemotherapy or radiation. Good nutrition may also help you prevent infections and remain more active.
Unfortunately, both cancer itself and some cancer treatments can affect your appetite. At times you simply may not feel like eating, or you may have nausea and vomiting as a result of chemotherapy. In that case, a registered dietitian can be especially helpful with food planning. The following suggestions also may help:
- Eat small, frequent meals rather than three large ones.
- Emphasize easily digested foods such as chicken soup or broth, plain boiled rice (or rice cooked in chicken broth), toast and baked potatoes. These are usually better tolerated than rich or spicy foods.
- Don’t worry if you just can’t eat for a day or two.
- Drink plenty of liquids, especially if you’re not eating.
|
| Coping skills |
A diagnosis of cancer can be extremely challenging. It's important to remember that no matter what your concerns or prognosis, you're not alone. Here are some strategies and resources that may make dealing with cancer easier:
- Know what to expect. Find out everything you can about your cancer — the type, stage, your treatment options and their side effects. The more you know, the more active you can be in your own care. In addition to talking with your doctor, look for information in your local library and on the Internet. The National Cancer Institute will answer questions from the public. You can reach them at 800-4-CANCER (800-422-6237) (800-422-6237). Or contact the American Cancer Society (ACS) at 800-227-2345.
- Be proactive. Although you may feel tired and discouraged, don't let others — including your family or your doctor — make important decisions for you. Take an active role in your treatment.
- Maintain a strong support system. Having a support system can help you cope with any issues, pain and anxieties that might occur. Although friends and family can be your best allies, they sometimes may have trouble dealing with your illness. If so, the concern and understanding of a formal support group or others coping with cancer can be especially helpful. Although support groups aren't for everyone, they can be a good source for practical information. You may also find you develop deep and lasting bonds with people who are going through the same things you are.
- Set reasonable goals. Having goals helps you feel in control and can give you a sense of purpose. But don't choose goals you can't possibly reach. You may not be able to work a 40-hour week, for example, but you may be able to work at least half time. In fact, many people find that continuing to work can be helpful.
- Take time for yourself. Eating well, relaxing and getting enough rest can help combat the stress and fatigue of cancer. Also, plan ahead for the downtimes when you may need to rest more or limit what you do.
- Stay active. A diagnosis of cancer doesn't mean you have to stop doing the things you enjoy or normally do. For the most part, if you feel well enough to do something, go ahead and do it. It's important to stay involved as much as you can.
- Look for a connection to something beyond yourself. Having a strong faith or a sense of something greater than yourself seems to be a key factor in successfully coping with cancer.
|
— March 10, 2003 —