Lung cancer is the number one killer among cancers in both men and women. It accounts for one-third of all cancer-related deaths in the United States. Although the number of men who get lung cancer has slightly decreased recently, the number of women who contract lung cancer has steadily risen. For nearly 40 years, breast cancer was the leading cause of death in women until lung cancer replaced it in 1987. In 1997, 178,000 new cases of lung cancer were diagnosed in the United States.
- Lung cancer defined
- Risk factors
- Signs and symptoms
- Evaluation and Staging of Lung Cancer
Lung cancer is divided into two categories: small cell lung cancer and non-small cell lung cancer. These two types behave differently and are, therefore, evaluated and treated differently. Small cell lung cancer, which includes oat cell carcinoma, is a more aggressive disease and is often more advanced at the time of diagnosis. Treatment usually involves chemotherapy and radiation therapy. Non-small cell lung cancer includes adenocarcinoma, squamous cell, and large cell cancer. Surgery is the primary treatment for early stage non-small cell lung cancer. Up to 80% of non-small cell lung cancer cases can be cured by surgery, depending upon the size of the tumor and if cancer cells have spread to other parts of the organ or the body.
Ninety percent of lung cancers are related to smoking. The risk of lung cancer is 30 times greater in smokers than in non-smokers and correlates with the total exposure to cigarettes, referred to as pack-years (packs smoked per day times the number of years smoked). One in seven people who smoke at least two packs a day will die of lung cancer. Cigar and pipe smoke double the risk of developing lung cancer, compared to nonsmokers. Approximately 5,000 to 10,000 Americans develop lung cancer per year from secondhand smoke.
Exposure to air pollution, radiation and industrial chemicals, such as arsenic, nickel, chromium and asbestos also increase the risk of lung cancer. Asbestos alone increases by four times the risk of getting lung cancer. The combination of asbestos and smoking increase the risk 90 times. Asbestos exposure is also associated with mesothelioma, a type of cancer that starts in the pleural lining of the chest.
Signs and Symptoms
Lung cancer may be found as a mass or tumor on the chest X-ray of a patient with no symptoms, but most patients have symptoms when diagnosed. Symptoms may include:
- A new cough, a change in an existing cough and a bloody cough.
- Rib or shoulder pain.
- Loss of appetite.
- Weight loss.
- Facial swelling.
- Bone pain.
A chest X-ray is the first step in evaluating lung cancer. Normal X-ray procedures give a good picture of the chest cavity, but a CT scan (an advanced X-ray system) is usually done to show the lung mass, lymph nodes and the rest of the chest cavity in much greater detail. These X-rays may help evaluate the extent of a lung mass and suggest the likelihood of cancer. A diagnosis of lung cancer, however, requires a biopsy.
An MRI (magnetic resonance imaging) may be part of the evaluation for a lung mass. It is especially useful in evaluating the brain and bones, but it does not visualize the lung well.
A PET scan is a relatively new nuclear medicine technique that may be very helpful in evaluating and identifying the stage of a lung mass. If a lung mass "lights up" on the PET scan, it is a lung cancer most of the time. If the mass does not light up on the PET scan, it is not likely to be a cancer. The test also evaluates the entire body to see search for any evidence that the tumor has spread to lymph nodes or other areas of the body
Although X-rays may suggest the presence of cancer, a biopsy is needed to make the diagnosis. Biopsy is the removal and examination of biological tissue, cells or fluids. A biopsy may be performed in several ways.
Sputum: A patient can cough up a sputum sample to look for cancer cells. Sputum cytology will diagnose 75% of tumors located in the bronchi (windpipes), but only 25% of tumors located toward the edge of the lung. Most lung cancers are not in the windpipes so most cancers are not diagnosed by sputum tests. If the test does not diagnose cancer, there is no guarantee that cancer is not present.
Needle biopsy: A needle biopsy is a technique in which a radiologist anesthetizes the skin and inserts a needle through the chest into a lung mass. This is usually done in the radiology department with a CT scan to accurately direct the needle. This will diagnose 60 to 90% of lung cancers, depending on the size and location of the cancer. Even under the best circumstances, however, a needle biopsy sometimes fails to diagnose some masses that are actually lung cancers. Therefore, if the test does not diagnose cancer, there is no guarantee that the lung mass is benign (not cancer).
Bronchoscopy: Another method to obtain tissue is flexible bronchoscopy. The bronchoscope is a flexible, hollow tube that is inserted through the mouth or nose and into the bronchi (windpipes). The procedure may be performed under light sedation or a general anesthetic. If a tumor is seen in the windpipe, a tissue sample can be obtained. Light bronchoscopy is a special bronchoscope that uses a special type of light to identify cancers not seen with standard light. Most lung cancers are not visualized with the bronchoscope because they are located toward the edge of the lung, rather than in a major bronchus.
EndoBronchial UltraSound (EBUS): EBUS is a technique with a special bronchoscope that has an ultrasound on the tip. The ultrasound identifies lymph nodes on the outside of the windpipes. The ultrasound then helps the surgeon pass a needle into the lymph node to determine if there is cancer in the node. This can both make a diagnosis and stage a lung cancer.
Mediastinoscopy: Cervical mediastinoscopy is a surgical procedure that is done under general anesthesia in the operating room. Through a one-inch incision in the neck, the surgeon follows the windpipe into the chest to remove lymph nodes. This procedure can be done on an outpatient basis. It is an important test because it not only can diagnose a lung cancer, but it also indicates the extent of the tumor so it helps determine the proper treatment. This is most often an outpatient procedure. Sadly, in the United States, about half of the mediastinoscopy procedures produce no lymph nodes for biopsy. There should be several nodes removed with this procedure. (Little)
Wedge Resection: A surgical biopsy may be necessary to determine whether or not a lung mass is a cancer. This requires hospital admission and a general anesthetic. Often, the biopsy can be obtained with three small (half-inch) incisions in a procedure called thoracoscopy or video-assisted thoracic surgery (VATS). A camera is placed through one of the incisions, while the pathologist places surgical instruments through the other incisions to remove the lung mass for examination. If cancer is found, then a complete cancer operation is performed while the patient is still asleep.
Small cell cancer accounts for about 25% of all lung cancer. It is staged as either limited disease (confined to the chest) or extensive disease (spread outside the chest). Small cell cancer is usually treated with chemotherapy and radiation therapy. It is rarely treated with surgery because by the time it is diagnosed it has usually spread to other parts of the body, even if the tests do not prove it.
Non-small cell lung cancer: There are four stages of non-small cell lung cancer. This staging system is important for determining the prognosis and treatment for lung cancer.
- Stage I is a cancer confined to the lung and usually treated with an operation.
- Stage II cancer that has spread to lymph nodes near the tumor and within the lung is usually treated with an operation, but may be subsequently treated with chemotherapy and/or radiation.
- Stage III cancer is confined to the chest, but it has spread more widely through the tissues in the chest.
- Stage IV cancer has spread to other parts of the body, such as the brain, liver or bones.
Evaluation and Staging of Lung Cancer
The staging and evaluation of a lung cancer involves a history and physical examination and several other tests. Knowing the stage of your cancer helps you and your doctor develop a proper treatment plan. Tests will also determine if you have the lung capacity to undergo treatment.
Pulmonary Function Tests: Pulmonary function tests are done to see if the patient has enough lung function so that an operation can be performed safely. The patient breathes into a machine to determine the lung capacity. If the pulmonary function test is good, then a lobectomy is the usual treatment. If the pulmonary function is not adequate, there are other surgical and non-surgical treatment options.
Brain CT Scan or MR: Lung cancer may travel to the brain so imaging of the brain is performed if the patient has headaches or neurologic symptoms, weight loss, or appears to have a more advanced stage tumor. If there are no symptoms and the tumor appears to be early stage, this is often not done because the chances of finding the tumor in the brain is low.
CT Scans: A CT of the chest is needed to evaluate the tumor. The surgeon needs to look at the tumor to determine the location so the surgeon knows where to resect and the relation of the tumor to surrounding structures to determine the extent of the resection needed to remove the tumor (just the mass, a section of the lung or the entire lung).
PET Scan: Parts of the body with an active metabolism (such as the brain, liver, tumors) absorb more glucose than other parts of the body so Fluorodeoxyglucose is injected to identify these areas. This test is often used to evaluate a mass in the lung and determine if there is spread elsewhere. In general, if a mass in the lung lights up on the PET scan, there is an 80 to 90% chance that it is cancer. A false positive test can occur if the mass is inflammatory or infection. If the lung mass does not light up on the PET, the chances of the mass being cancer are only 5%. False negative tests occur if the mass is small (<1 cm) or a low grade, slow growing tumor, such as broncho-alveolart cancer (BAC, now known as AIS). The PET scan evaluates the mediastinum (middle of the chest) to see if the lymph nodes are involved. False positive tests occur up to 25% of the time; this may be due to infection, inflammation, or anthrocosis. False negative tests occur if the area of tumor on the lymph node is small (<1 cm). Nodes that are positive on the PET generally need to be biopsied to determine if there really is tumor there.
Bone Scan: A bone scan or a brain scan, may be done to see if the tumor has metastasized (traveled) to other parts of the body.
Cedars-Sinai, through its Samuel Oschin Comprehensive Cancer Institute, offers state-of-the-art treatment for all stages of lung cancer, including investigational studies involving new treatments that are not otherwise available. A highly integrated team approach to treating patients is an integral part of our program. Multimodality therapy is often required so the surgeons, pulmonary specialists, oncologists and radiation therapy specialists work together to formulate the best treatment plan for each patient. A tumor board and a lung cancer clinic are options for reviewing lung cancer cases so the specialists can discuss the cases to recommend treatment approaches. We are dedicated to providing the most up-to-date and compassionate care for our patients. As with all cancers, lung cancer may be treated with surgery, chemotherapy, radiation therapy or a combination thereof. The treatment depends on the type and the extent of the cancer.
Surgery for Lung Cancer
Surgery offers the best chance of a cure for lung cancer and is the treatment of choice for early stage non-small cell lung cancer, but it is not very effective for more advanced stage cancers. Operations are performed when the tumor appears to be confined to the lung and when the procedure can be performed safely. The operation involves removing the cancer and lymph nodes from the chest.
The right lung has three lobes (right upper lobe, right middle lobe and right lower lobe) and the left lung has two lobes (left upper lobe and left lower lobe). A segmentectomy or wedge resection is the removal of less than an entire lobe, a lobectomy is the removal of an entire lobe and a pneumonectomy is the removal of the whole lung.
Lobectomy: The most common lung cancer operation is a lobectomy. This has been proven to have a lower chance of cancer recurrence in the lung and to have a higher cure rate than a wedge resection or segmentectomy for a Stage I lung cancer. The cure rate for lung cancer surgery varies from 20 to 80%, depending on the stage of the tumor. For lung cancer surgery, patients are generally admitted to the hospital for three to seven days. The operation is done under general anesthesia. The most common risk is pneumonia, so patients are out of bed on the day of the operation and walking in the halls the day after the operation. During the operation, drainage tubes are placed into the chest cavity. These are connected to a collection system. These tubes are removed from the chest several days after surgery.
VATS Lobectomy: The program for the treatment of lung cancer at Cedars-Sinai Medical Center has led the charge into the 21st Century. In the United States, about 80% of lung surgery is done through large incisions (6-8 inches long) under the arm. In contrast, the surgeons at Cedars Sinai developed minimally invasive surgery for lung cancer. At Cedars Sinai, over 90% of lung cancer surgery is performed with small incisions (Usually about 2 inches). Less than 3% are planned VATS operations converted to thoracotomies. Using the most advanced surgical technology available, our surgeons perform the same operation that other surgeons perform through the large incisions. In the US, there are many operation performed in which the nodes are not removed, but that is important for complete removal of the tumor, for prognosis, and to determine if additional treatment is needed. Cedars-Sinai is proud to be one of the few institutions in the world capable of offering patients complete lung cancer operations via minimally invasive surgery, which results in less pain, shorter hospital stays and faster recovery than traditional, invasive, rib-spreading operations. At Cedars Sinai, our surgeons have the largest experience in the world with VATS lobectomies (over 2700 cases).
Segmentectomy: Each lobe has smaller sections called segmentectomies. There are cases where the tumor is small, where the tumor does not require much tissue to be removed (carcinoid or BAC), or where the patient cannot tolerate the removal of an entire lobe so a segmentectomy can be performed. At Cedars Sinai, segmentectomy, when indicated, are also routinely performed by VATS.
Pneumonectomy: In <10% of cases, the entire lung (pneumonectomy) is required due to the extent of the tumor. This also can be performed with VATS.
Thoracotomy: A thoracotomy (big incision under the arm) is still the most common approach in the US for lung surgery. At Cedars Sinai, this is uncommon, but there are still some indications for a thoracotomy: if the tumor is too large to be removed through a small incision, if the tumor is attached to ribs that need to be resected, if the patient underwent chemotherapy and radiation before the operation, or if situation during the operation requires a thoracotomy. At Cedars Sinai, 3% of planned minimally invasive operations are converted to a thoracotomy.
Chemotherapy: Chemotherapy involves the administration of cancer-killing medication, usually via the veins. It may be used to shrink a cancer prior to a resection, to prevent recurrence of cancer after an operation or for patients who have extensive cancer that cannot be resected. There are many different chemotherapy drugs, and the side effects vary with the different medicines. Chemotherapy alone does not cure non-small cell lung cancer, but it is the primary treatment for small cell lung cancer.
Radiation Therapy: Radiation therapy is an X-ray treatment that usually takes a short time and is given every day for several weeks. Like chemotherapy, it may be given prior to surgery, after surgery or instead of surgery. The side effects are usually minimal and may include a tiredness, skin burns similar to sunburn, esophagitis and nausea. Although radiation may cure lung cancer, only 5 to 10% of patients who receive this therapy are considered cured.
Selected Research Articles on Lung Cancer
- Mediastinal evaluation in lung cancer. Libshitz HI, McKenna RJ Jr, Haynie TP, McMurtrey MJ, Mountain CT. Radiology 1984 May; 151(2): 295-9
- Mediastinal lymph node size in lung cancer, Libshitz HI, McKenna RJ Jr., AJR Am J Roentgenol 1984 Oct;143(4):715-8
- Roentgenograph3ic evaluation of mediastinal nodes for preoperative assessment in lung cancer. McKenna RJ Jr., Libshitz HI, Mountain CE, McMurtrey MJ, Chest 1985 Aug;88(2):206-10
- Patterns of mediastinal metastases in bronchogenic carcinoma., Libshitz HI, McKenna RJ Jr., Mountain CF., Chest 1986 Aug;90(2):229-32
- Surgical resection of stage IIIA and stage IIIB non-small-cell lung cancer after concurrent induction chemoradiotherapy. A Southwest Oncology Group trial
- Neoadjuvant therapy: a novel and effective treatment for stage IIIb non-small cell lung cancer. Southwest Oncology Group
- Concurrent cisplatin/etoposide plus chest radiotherapy followed by surgery for stages IIIA (N2) and IIIB non-small-cell lung cancer: mature results of Southwest Oncology Group phase II study 8805