What is lung cancer?
Like other cancers, lung cancer develops when normal processes of cell division and growth are disrupted, giving way to abnormal, uncontrollable growth. The cells grow into a mass, or tumor. Any abnormal growth in the body that directly invades surrounding tissues and organs, spreads to other parts of the body, or has the potential to grow back after being removed is called “malignant,” or cancerous.
Who gets lung cancer?
Lung cancer can take several years to develop. Cigarette smoking is the most common risk factor for developing lung cancer. Many people exposed to cigarette smoke – or some of its components – will end up with permanent abnormal changes in their lungs. These changes can cause a cancerous tumor to develop within the lung.
- Twenty-five percent of all cases of lung cancer worldwide are diagnosed in people who have never smoked. The underlying cause in these cases is not well understood.
- Two out of three people diagnosed with lung cancer are over age 65.
- The most common age at diagnosis is 70 years.
How common is lung cancer?
Lung cancer is the most common malignancy worldwide, with more than 1 million cases diagnosed yearly. In the United States, an estimated 200,000 new cases were diagnosed in 2009. More than 150,000 deaths in 2009 were due to lung cancer – making it the leading cause of cancer death in both men and women. Of those people born today, one in 14 men and women will be diagnosed with cancer of the lungs and bronchus (large air tubes leading from the windpipe to the lungs) during their lifetime.
How is lung cancer diagnosed and managed?
Usually, concern that a patient may have lung cancer starts when an abnormal finding is seen on a chest imaging study (chest X-ray or CT scan) or when the disease is advanced enough to cause symptoms, such as coughing, shortness of breath, chest pain, fatigue and/or weight loss.
Diagnosis requires a biopsy, or the removal of cells or tissues from the suspicious mass. Biopsies can be performed through a camera fed through the breathing tubes (called bronchoscopy) or from a needle inserted through the skin into the lung tumor. If these approaches are not successful, surgery may be required for an adequate diagnosis. The biopsy is important in determining whether or not it is cancer, and to determine which type of lung cancer is present.
What are the stages of lung cancer?
Staging allows the physician to fully understand the extent of the patient’s cancer to help make treatment decisions and determine expected outcomes. Doctors use specific terms to describe the stages of cancer, but a straightforward way of describing staging might be as follows:
- Localized: the cancer is confined to the lung.
- Regional: the cancer has spread to lymph nodes (or glands) within the chest. Lymph nodes act as a filtering system outside the lung, collecting cancer cells that are beginning to migrate out of the lung.
- Distant: the cancer has spread (or metastasized) to other parts of the body.
What are the types of lung cancer?
About 90 percent of lung cancers start in the lining of the bronchi (air passageways branching off the trachea, or breathing tube). Lung cancer also can form in glands below the lining of the bronchi, frequently in the outer edges of the lungs. These lung cancers are one of two major types, small cell or non-small cell lung cancer, each of which grows and spreads different ways:
Non-small cell lung cancer
Non-small cell lung cancer is much more common, and usually grows and spreads more slowly than small cell lung cancer. There are three main types of non-small cell lung cancer, named for the type of cells in which the cancer develops:
- Adenocarcinoma often starts growing near the outside surface of the lung and may vary in both size and growth rate. This is the most common type of lung cancer in both smokers and those who have never smoked.
- Squamous cell carcinoma usually starts in one of the larger breathing tubes near the center of the chest. The size of these lung tumors can range from very small to quite large.
- Large cell carcinoma often starts near the surface of the lung, grows rapidly and is usually quite extensive when diagnosed.
Small cell lung cancer
Small cell lung cancer is less common than non-small cell lung cancer accounting for about 15 percent of all lung cancers. This type of lung cancer grows fairly rapidly, is likely to be advanced by the time of diagnosis and spreads to other parts of the body quickly.
Rare cancers of the chest
There are more than a dozen kinds of uncommon tumors that can develop in the chest, which may or may not arise from the lung. Some of the less common types include carcinoid tumors (often located in a large airway), and malignant mesothelioma that develops from the pleura, or lining of the lung.
Mesothelioma is a cancer that affects the mesothelium, the protective membrane that covers most of the body’s internal organs. This rare cancer affects only about 3,000 people annually, usually in the part of the mesothelium surrounding the lungs (pleura) but sometimes in the pericardium that covers the heart. Mesothelioma usually happens decades after exposure to asbestos.
How is lung cancer treated?
All relevant information about the patient, including his or her health status, the kind of tumor and how far it has spread are brought together to design the most appropriate therapy for that individual’s cancer.
Lung cancer is a very challenging cancer to treat. The most critical factor in determining the survival rate is the stage at the time of diagnosis. Those that are diagnosed at a localized stage are curable. Unfortunately, most people are diagnosed when the disease has spread outside the chest (advanced or distant) or involves the nodes in the chest (regional). Also, the lungs are very sensitive organs and may not handle some forms of treatment easily. This helps explain why lung cancer has one of the poorest survival rates of all cancers. Two-year survival rate of those diagnosed with lung cancer is 25 percent. At five years, survival rate drops to 15 percent.
It is important to discuss the goals of lung cancer treatment with your doctor. Some treatments may be used to control the cancer. Others are used to improve quality of life and/or reduce symptoms. These treatments may be used alone or in combination.
Chemotherapy and targeted therapies
Chemotherapy is the use of drugs that are designed to kill rapidly growing cells, such as cancer cells. Chemotherapy may be injected directly into a vein (by IV, or intravenously) or given through a catheter, which is a thin tube placed into a large vein and kept there until it is no longer needed. Some chemotherapy drugs are taken by pill.
Targeted agents are a newer class of drugs that are designed to act against specific weaknesses in cancer cells or surrounding supportive tissues, such as blood vessels. These drugs can also be taken by pill or by IV. They are most effective in cancers with specific changes in their genes.
In early stages of non-small cell cancer, chemotherapy may be used in conjunction with surgery to improve survival rates. In more advanced stages of non-small cell cancer and in all stages of small cell cancer, chemotherapy and targeted therapies may be used to relieve symptoms and extend life.
These therapies affect both normal cells and cancer cells. Your doctors will try to prevent side effects as much as possible while treating the cancer appropriately. Side effects depend largely on the specific type of drug and the amount given. They can be different for each person and may be only temporary. Common side effects of chemotherapy include nausea and vomiting, hair loss, mouth sores and fatigue. Your health care providers can suggest ways to make any side effects more manageable and to help relieve symptoms that may occur during and after procedures.
Radiation therapy is a form of high energy X-ray that kills cancer cells. It can be used as a primary treatment, or in combination with chemotherapy (with or without surgery). It often can play an important role in advanced cancer patients by providing relief from pain, blockage of the airways, shortness of breath or coughing.
Radiation therapy is a “focused” treatment, meaning it is designed to maximize its effect on the cancer cells while minimizing any injury to normal cells. Radiation to treat lung cancer most often comes from a machine (external radiation). Occasionally, the radiation may be delivered internally using tubes that place a radioactive seed directly into or near the tumor (internal radiation or brachytherapy).
Side effects of radiation therapy depend mainly on the part of the body that is treated and the treatment dose. Common side effects of radiation therapy to the chest are a dry, sore throat; difficulty swallowing; fatigue; skin changes at the site of treatment; and loss of appetite.
An area of particular innovation in radiation therapy is a high-technology approach, sometimes termed “radiosurgery.” In very select patients who have small tumors but for whom surgery is unsafe, radiosurgery using very high doses of precisely focused radiation aimed only at the small tumor in the lung, is an effective alternative.
Surgery is still considered the “gold standard” for treating early-stage lung cancer. Removing the tumor and surrounding lung tissue gives the best chance for cure for patients whose disease is localized. Surgery should be performed by specialized thoracic surgeons with particular expertise in treatment of lung cancer and other chest malignancies. Your surgeon will determine whether a tumor is resectable (removable). Not all tumors are resectable due to their location near – or if they have invaded – vital structures.
In some patients with multiple medical problems or poor lung function, surgery may not be the best option. This is carefully determined by our multidisciplinary team including pulmonologists, medical oncologists and radiation oncologists who work collaboratively daily.
Types of surgery
How much lung tissue will be removed and what type of surgical approach will be used depends on where the tumor is located in the lung, its size, patient’s body type/weight and any previous chest surgeries. All patients are considered first for minimally invasive surgery, although some complex cases may still require a traditional, open approach. Trained thoracic surgeons perform video-assisted thoracic surgery (VATS) and VATS lobectomy routinely as well as robotic surgery. Surgical resection of lung cancer is generally performed as:
- Limited resection: An operation to remove only a small portion of the lung is called a segmental or wedge resection.
- Lobectomy: Removal of large section of the lung, (there are three lobes of the lung on the right and two on the left), is called a lobectomy. This is the most common surgery performed for lung cancer.
- Pneumonectomy: The removal of an entire lung is called a pneumonectomy.
Recovery after thoracic surgery depends on the extent of the surgery, whether or not it is performed minimally invasively as well as the age and overall fitness of the patient. Many patients return home within three to four days after surgery. Patients who undergo minimally invasive surgery can generally return to work three weeks after surgery.
For some patients, participating in a clinical trial may be the best treatment choice. Clinical trials are done to find out if new cancer treatments are safe and effective, or to see if they are better than the standard treatment. Many of today’s standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.
Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move medical knowledge forward.
Life after treatment
Your health care providers will help you understand what to expect after cancer treatment in terms of follow-up care, lifestyle changes, and making important health-related decisions.
If lung cancer is localized or regional and treatment has been administered with the intention of curing the cancer, follow-up testing will be performed to ensure the cancer does not recur. You also will be assessed for side effects related to the treatment received, and treatment will be offered to help with any related symptoms.
Follow-up in patients whose lung cancer is metastatic and/or treatment was intended to improve the quality of life and extend life will be tested over time to determine how the cancer is responding to treatment, and to monitor for side effects from therapy. The length of treatment or the need to change therapies will be determined by these follow-up tests.
Related patient services for lung cancer patients
Chronic diseases and disorders of the lungs and airways, as well as some of the invasive treatments for them, can take their toll on health and quality of life. Pulmonary rehabilitation programs use an array of tactics – from education and exercise to encouraging lifestyle changes – to help our patients manage their conditions.
Pain can be a significant issue for people undergoing cancer treatment. Various cancer interventions, as well as the cancer itself, can cause pain. Effective pain management can help maintain or improve quality of life and even help reduce the risk of depression associated with pain.
Smoking is a major cause of lung cancer, but quitting can be a challenging proposition for some chronic smokers. As smoking patterns vary from person to person, there is no “best” method for quitting. The most successful smoking cessation programs offer smokers a range of strategies.
Lung cancer screening
Lung cancer screening means identifying lung cancer at an early stage prior to the development of symptoms. Recent evidence suggests that reduced-dose chest CT imaging helps save lives in those people at highest risk of developing lung cancer. At Cleveland Clinic, we have a comprehensive lung cancer screening program for those individuals at high risk of developing lung cancer (aged 55 to 79, 30+ pack-years of smoking, smoked within the past 15 years).
- Lungcancer.org. A program of Cancercare™. Accessed 8/2/2013.
- National Cancer Institute. Lung Cancer. Accessed 8/2/2013.
- American Lung Association. Lung Cancer. Accessed 8/2/2013.
- Mazzone P. Lung cancer screening: examining the issues. Cleve Clin J Med. 2012;79 Electronic Suppl 1(e-Suppl_1):eS1-6.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 8/2/2013…#4375