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Lung Cancer
What is lung cancer?
Cancers are diseases caused by the out-of-control growth of cells in the body's tissues that invade and destroy the normal cells around them. They are named for the organs or systems of the body in which they first develop, and more than 100 types of cancer have been defined. Since differing types of cancers grow at different rates and respond in their own ways to individual forms of therapy, each has its own method or methods of treatment.
As the name suggests, lung cancer originates in the lungs. There are two major types of lung cancer: small-cell lung cancer and non-small-cell lung cancer.
The small-cell version, accounting for about 20 percent of all lung cancers, tends to spread to other parts of the body more rapidly than the non-small-cell variety and usually requires treatment with a systemic, or body-wide, approach. By and large, this means chemotherapy.
About 80 percent of all lung cancers are of the non-small-cell form, which grows more slowly. While non-small-cell lung cancer that has spread beyond the lung may require systemic treatment as well, non-small-cell cancer that is detected while still confined to the lungs may be treated effectively by surgery to remove the tumor in the lungs.
In either case, lung cancer represents a disease that is particularly dangerous in its capability to develop over many years before displaying symptoms that may reveal its presence.
The physicians of Connecticut Surgical Group have extensive experience in the treatment of lung cancer and have been leaders in the development of surgical techniques. They offer significant resources for treatment of your cancer.
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What do the lungs do?
Beyond their obvious role of allowing us to breathe, the cone-shaped, sponge-like lungs serve the function of replenishing the blood stream with oxygen needed by cells throughout our bodies and removing the carbon dioxide gas our cells give off as waste.
The trachea (or windpipe) that carries air into the chest divides into two smaller tubes called the bronchi, which then divide into numerous smaller branches called the bronchioles, leading to even-smaller air sacs called the alveoli. It's here that the blood stream exchanges oxygen for carbon dioxide.
The right lung has three sections, or lobes. Because it shares its area of the chest with the heart, the left lung has two lobes. Lung cancer most often originates in the bronchi, but it also can begin in the other areas. Of major concern is whether the cancer has spread beyond the lung itself.
For this reason, attention is paid to the lymph system as well. Lymph is a watery substance that carries tissue waste and immune-system cells throughout the body, but it is also a means by which cancer cells travel to other areas of the body. The lymph vessels carry lymph between the lymph-nodes, or bean-sized glands where lymph (and cancer cells) collects. Often during a biopsy, the doctor will remove a number of lymph nodes to be checked.
A sentinel node is a node that has been identified as one of the first to which lymph travels from the lungs; by removing and analyzing that node it can be determined whether the cancer has spread that far. While a positive analysis will likely make additional testing or more extensive treatment necessary, a negative result can provide assurance that the cancer has not spread.
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How common is lung cancer?
Lung cancer is the second most common form of cancer (after skin cancer) in the United States, and the leading cause of cancer death.
Nearly 170,000 new cases of lung cancer are reported each year, and nearly 155,000 people die from it. About 90,000 are men and 65,000 are women. (More women die each year of lung cancer than of breast cancer.) The average age of newly diagnosed patients is 60.
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What causes lung cancer?
- Smoking: Smoking tobacco is considered the leading cause of lung cancer by far. The development of lung cancer as a wide-spread disease parallels the steadily increased availability of manufactured cigarettes throughout the 20th Century. Today 80 percent of lung cancers are believed to be related to smoking.
Carcinogens in tobacco smoke can damage cells within your lungs, setting them up to potentially become cancerous over time. The good news is that if you stop smoking, your damaged cells can gradually return to normal. It's estimated that after 10 years your risk will be reduced to about 30 percent of the risk if you continue to smoke.
Low tar and heavily filtered cigarettes are not viewed as reducing your risk. Studies indicate that smokers of "light" cigarettes inhale more strongly and achieve similar levels of carcinogens.
And despite a common belief that cigar and pipe smokers are not at risk because they don't inhale as strongly, if nothing else, they are breathing in the second-hand smoke of those cigars and pipes.
Second-hand smoke breathed by non-smokers can be a significant risk factor, as well. According to the American Cancer Society, a non-smoker married to a smoker has a 30 percent greater risk of developing lung cancer than the spouse of a non-smoker.
- Other Causes: Each breath you take potentially exposes you to a range of pollens, dusts, viruses and substances such as toxic chemicals from industry, fuels such as gasoline, and other contaminants.
People who work with asbestos are considered much more likely to develop lung cancer than those who don't. Fortunately, while asbestos was commonly used in manufacturing and construction in the past, it's used much less today. Asbestos is still present in many older homes, schools and other buildings, but it's not considered a risk as long as it is contained behind walls and ceilings. If you set out to renovate a building containing asbestos, however, you will need to take precautions.
Radon, an invisible, odorless gas produced naturally when uranium degrades and present in soil and rocks in many areas, can also cause cancer. Outdoors, it's so dispersed that it is not a risk factor. But it can become concentrated in homes (especially basements) built over such areas, creating a risk for people who live with it over a long period of years. Tests to detect radon are available at many hardware stores, and corrective measures are available when it is present.
Individuals who have had cancer and have been treated for it are considered to be at a higher risk of developing it again. For any patient treated for cancer, there is the possibility of the spread of undetected cancerous cells that can lead to recurrence of the disease over a period of time.
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What are the symptoms of lung cancer?
Early stage lung cancer may not display any symptom. The patient may consult a physician because of a cough that will not go away.
Other symptoms that warrant examination include:
- Coughing up blood — even a small amount
- New onset of shortness of breath
- New onset of wheezing
- Repeated cases of pneumonia or bronchitis
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How is lung cancer diagnosed?
Unlike some cancers where screening tests offer a chance of detecting a cancer before its becomes symptomatic, this is rarely the case with lung cancer. It is a regrettable fact that only a small percentage of cases are found before symptoms become obvious. Although the regular chest x-ray to detect lung cancer was a staple of the annual physical for many years, the unfortunate fact is that it has not proven to be a meaningful test in terms of saving or extending lives.
The National Cancer Institute launched a major study in the fall of 2002 to assess the usefulness of a test called spiral CT scanning (CT stands for computerized tomography, basically a highly detailed computer-link x-ray system) compared to standard x-ray. Spiral CT can detect early lung lesions, but its false-positive rate is fairly high, causing to many patients to undergo biopsy procedures for masses that are not cancerous.
Once lung cancer is suspected, there are a variety of tools that can be used to confirm, analyze and measure the extent of abnormal tissue.
These include:
- Bronchoscopy, the use of a thin, fiberoptic instrument to enable your doctor to see inside your lungs and to collect cells and tissue samples for examination
- Mediastinoscopy, an endoscopic procedure to take a sample from lymph nodes in your chest through an incision at the base of the neck
- Mediastinotomy, an endoscopic biopsy procedure within the chest itself
- Video thoracoscopy, an endoscopic technique that uses a video system to guide a surgical biopsy of the lung, lymph nodes or chest wall
- Needle aspiration, the collection of sample cells with a needle inserted through the chest into the tumor
- Thoracotomy, a surgical procedure accessing a suspicious mass by opening the chest
In all these techniques where biopsies are taken, the tissue samples are examined under a microscope by a physician called a pathologist in order to assess whether they are cancerous or not, and if so, their type.
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What are the major types of lung cancer?
Lung cancers are grouped into two major types: Small cell lung cancer and non-small cell lung cancer. Each grows in different ways and has its own set of classification and treatment protocols.
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What are the stages of small-cell lung cancer?
Small-cell lung cancer accounts for about 20 percent of all lung cancers, but it is by far the more aggressive version, developing and spreading rapidly. It is staged as either limited — confined to one lung and the lymph nodes on the same side of the chest — or extensive. Extensive means the cancer has spread to the other lung and its associated lymph nodes, and/or to other parts of the body.
As the name suggests, the cells are small. However, it can form large tumors. Small-cell cancer is sometimes called by the names small-cell undifferentiated carcinoma and oat cell cancer. Almost 100 percent of cases with this version of lung cancer are found in smokers.
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What are the treatment options for small-cell lung cancer?
Because it spreads throughout the body so rapidly, surgery is rarely an effective option for small cell lung cancer. The most commonly used treatment is chemotherapy — the use of chemicals body to attack and kill cancer cells throughout the body. Chemotherapy is a systemic treatment: chemotherapy agents administered in the form of pills or intravenous fluids travel throughout the bloodstream and attack cancer cells wherever they are. There are a large number of chemotherapy agents and treatment protocols vary with each.
Other treatments such as surgery and radiation therapy might be options for small-cell cancer that is detected very early and is truly limited to only one lung and close-by lymph nodes. They are described in some detail below. In some cases, prophylactic cranial irradiation by external beam machines may be considered to seek to prevent spread of cancerous cells to the brain.
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What are the stages of non-small-cell lung cancer?
Technically, there are five types of non-small cell lung cancer — squamous cell carcinoma, adenocarcinoma, large cell carcinoma, adenosquamous carcinoma and undifferentiated carcinoma. They are named for the types of cells from which they begin or for their own cellular characteristics.
While non-small-cell lung cancer grows less aggressively than the small-cell version, it represents about 80 percent of all lung cancers. Its slower growth allows more detailed staging and more treatment options.
The stages of non-small-cell lung cancer are:
- Occult, or hidden stage: Cancerous cells are identifiable in mucus coughed up from the lungs even though no tumor can be detected in the lungs. At this stage, the cancer can usually be treated successfully.
- Stage 0: Cancerous cells are limited to one lung and are confined to a few layers of cells but haven't penetrated lung tissue. When caught at this stage, it can usually be treated successfully.
- Stage I: Cancerous cells are identifiable in lung tissue but haven't spread to the lymph nodes or other areas. When the cancer is treated at this stage, chances of surviving for five years are better than 50 percent.
- Stage II: Cancerous cells have invaded neighboring lymph nodes and other structures in the vicinity of the lungs (such as the diaphragm or the pleural sac surrounding the lungs). Chances of surviving for five years when the cancer is treated at this stage are 75 percent or less.
- Stage III is divided into two classifications:
- Stage IIIA: The cancerous cells have spread to lymph nodes outside the area of the lungs, but are still contained sufficiently to be treated surgically.
- Stage IIIB: The cancerous cells have spread to other areas of the chest, such as the heart, the esophagus and the trachea. At this point, the disease cannot be treated surgically and other therapies must be used. Chances of surviving for five years when the cancer is treated at this stage are less than 20 percent.
- Stage IV: Cancerous cells have spread to other areas of the body, such as the liver. Chances of surviving for five years when the cancer is treated at this stage are less than five percent.
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How is non-small cell lung cancer treated?
Surgery to remove the diseased portion of lung tissue is the treatment of choice for lung cancer if the cancer is limited to only one lung and close-by lymph nodes. For stages I, II and IIIA, it offers the best possibility of a cure and or at least long-term survival. For cancers at stages IIIB, IV and V, in which the disease has spread extensively, systemic therapies are likely to be considered more appropriate. Often, even surgery on cancers rated at stages I, II and IIIA will be followed up by other treatments such as chemotherapy and radiation therapy.
Depending on the extent of the abnormal tissue, the surgeon may remove only a small section (wedge resection), one of the lobes (lobectomy) or the entire lung (pneumonectomy). The technique for removing all or part of a lung is called a thoracotomy, reflecting the Latin term for the chest. Thoracotomy usually involves opening the chest from the side between the ribs.
- Wedge resection: A wedge resection is a procedure to remove the small section of the lung that contains the cancerous tissue.
- Lobectomy: With the right lung comprised of three lobes and the left lung of two, a lobectomy is surgery that removes an entire lobe of the affected lung.
- Pneumonectomy: A pneumonectomy is surgery to remove the entire lung that contains cancerous tissue.
Lobectomy is the most commonly performed procedure, since it offers the best chance of excising all cancerous tissue without compromising lung capacity significantly (especially in cases in which lung function might be diminished due to other disease). A wedge-resection may be done when a lobectomy might affect lung function too adversely, but it increases the chances of recurrence of the cancer. Conversely, removal of the entire lung may significantly affect lung capacity and is done reluctantly.
It also should be noted that in the course of a thoracotomy, the surgeon will sample lymph nodes in the chest (even if they have already been biopsied endoscopically) to make certain the cancer has not spread. If it appears that the cancer has spread significantly, he or she might not remove any lung tissue at all, considering the patient more appropriate for the systemic treatment of chemotherapy.
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How are other treatment used in conjunction with surgery?
With treatment techniques such as chemotherapy and radiation therapy available, one or more adjuvant therapies may be advised to ensure that any cancer cells that exist outside the area of surgery are destroyed.
- Chemotherapy is the use of chemical agents to attack and kill cancer cells. Chemotherapy is a systemic treatment: chemotherapy agents administered in the form of pills or intravenous fluids travel throughout the bloodstream and attack cancer cells wherever they are in the body. Since there are a large number of chemotherapy agents, there is no standardized treatment.
- Radiation therapy is the use of high energy rays to attack and kill cancer cells in specific areas of the body, usually performed in conjunction with surgery or chemotherapy. Radiation therapy usually involves the use of large external beam machines, with the radiation energy focused on cancerous tissue in order to protect normal tissue as much as possible. When appropriate, doctors may use techniques of brachytherapy, in which a tube may be inserted into the lung in order to place tiny radioactive "seeds" directly adjacent to cancerous tissue.
In some cases, prophylactic cranial irradiation by external beam machines may be considered to seek to prevent spread of cancerous cells to the brain.
- Photodynamic therapy uses laser light aimed at cancerous cells to activate a chemical injected into the bloodstream to target and kill the abnormal cells.
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What are possible side effects and complications of lung cancer treatments?
Treatment techniques are continually being improved upon, but, realistically, many of them still carry serious side effects with them.
Following lung surgery, a patient can expect to spend approximately a week in the hospital and at least a month recovering at home. To promote full expansion of the remaining lung, it is important to encourage coughing and breathing deeply. Shortness of breath, muscle weakness and pain may be present.
Side effects of chemotherapy can vary from drug to drug, but they often include loss of hair, nausea and vomiting, and general fatigue.
Similarly, the side effects of radiation therapy can vary according to the area being treated and the strength of the treatment. Patients receiving radiation therapy frequently experience skin changes in the area being treated, sore throat and difficulty swallowing, general fatigue and loss of appetite. Radiation treatment of the cranium may additionally result in hair loss and difficulties with memory and cognitive processes.
With all cancers at any stage there is the possibility of the spread of undetected cancerous cells that can lead to recurrence of the disease over a matter of months or years. Individuals who have had cancer and have been treated for it are considered to be at a higher risk of developing another cancer later.
And, it should be kept in mind that all medical procedures carry slight risks of adverse reaction to anesthesia, infection and bleeding.
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Besides receiving medical help, what should I do to deal with my cancer?
The most important thing for you to do if you've been diagnosed with lung cancer is to not smoke and to stay away from smoky environments. Even though you already have cancer, avoiding smoke will maximize remaining lung function and enhance your physical condition while going through treatment.
In the same light, following a healthy diet and exercising regularly (say, walking, swimming or bicycling for at least 30 minutes four times a week) can help you to maximize your physical and emotional well-being — and your response to treatment.
If you are experiencing shortness of breath, you may want to talk to your physician about being prescribed for the use of supplemental oxygen.
In addition, finding emotional support is important for you, whether through an informal network of family and friends or through formal support groups sponsored by area hospitals and other organizations. Learning about lung cancer can help you understand the issues, treatment options and processes being faced. Staying as active as possible is essential for you.
And, regular follow-up visits with your medical caregivers is important in monitoring progress and making certain that any changes in your medical status are detected quickly.
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What can I or my loved ones do to prevent lung cancer?
There are some risk factors for lung cancer, such as family history and genetic predisposition, that we can't alter.
But we can control the most important risk factor for lung cancer: don't smoke cigarettes, cigars or pipes, and avoid environments where such smoke exists. Remember: 80 percent of lung cancer cases are associated with smoking.
Many hospitals and national organizations such as the Red Cross and the American Lung Association offer workshops on quitting smoking. Products such as nicotine patches and gum are available to help in the effort to stop.
Awareness of asbestos, chemical hazards and radon concentrations are also important for preventing lung cancer. Local public health boards and the Environmental Protection Agency, among others, are concerned with monitoring asbestos and chemical problems. Radon detectors can be purchased at most hardware stores.
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For more information:
You can find much additional information about lung cancer at web sites sponsored by government agencies, societies and healthcare institutions. It should perhaps be noted that the World Wide Web is open to many sources posting questionable information and promises, and you are encouraged to seek information from established, reputable organizations.
Likely sources include:
American Cancer Society
www.cancer.org
American Lung Association
www.lungusa.org
The National Cancer Institute (NCI)
www.cancer.gov
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