Small Cell Lung Cancer

Small cell lung cancers (SCLC) account for roughly 13% of all lung cancers1 and are primarily diagnosed in smokers or former smokers. They differ from other types of lung cancer in that they spread very quickly throughout the body via the blood and lymphatic system.

Accurate staging of small cell lung cancer is essential before definitive therapy can begin. For many years, a simple staging system has been used to separate small cell lung cancer into two stages: limited and extensive. More recently, the International Association for the Study of Lung Cancer (IASLC) developed a new TNM (tumor, node, metastasis) system of staging that classifies small cell lung cancer into several categories ranging from Stage 0 to Stage IV.2 Because the two-stage system continues to guide treatment decisions, that is the system that is used on this website.

Limited and extensive small cell lung cancer are treated differently; therefore, your primary cancer doctor will perform a variety of tests to determine the stage of the disease and thus, the optimal treatment strategy. If these staging tests suggest that your cancer is confined to one side of your chest, then you will be diagnosed with limited stage small cell lung cancer. Otherwise, you will be diagnosed with extensive disease. Select from the following general stages of cancer in order to learn more about treatment options.

Limited Small Cell Lung Cancer: The cancer is confined to a single side of the chest.

Extensive Small Cell Lung Cancer: The cancer is not confined to a single side of the chest.

Recurrent/Relapsed: The lung cancer has been detected or returned (recurred/relapsed) following an initial treatment.

Staging: Determining the stage or extent of spread of the cancer is essential in order to understand treatment options or interpret published cancer treatment information. Determining the stage of lung cancer may require many tests, which often include the following:

Mediastinoscopy: A mediastinoscopy is a procedure that can indicate whether the cancer has spread to the lymph nodes in the chest. During a mediastinoscopy, a surgeon inserts a mediastinoscope (lighted tube) through a small incision in the neck while a patient is under general anesthesia. This mediastinoscope allows the surgeon to examine the center of the chest (mediastinum) and nearby lymph nodes, as well as remove a tissue sample.

Computed Topography or CT Scan: A CT scan is a technique for imaging body tissues and organs, during which X-ray transmissions are converted to detailed images, using a computer to synthesize X-ray data. A CT scan is conducted with a large machine positioned outside the body that can rotate to capture detailed images of the organs and tissues inside the body. This method is more sensitive and precise than the chest x-ray.

Magnetic Resonance Imagery or MRI: During MRI, a powerful magnet linked to a computer makes detailed pictures of areas inside the body.

Positron emission tomography (PET): Positron emission tomography (PET) scanning has been used to improve the detection of cancer in lymph nodes. One characteristic of living tissue is the metabolism of sugar. Prior to a PET scan, a substance containing a type of sugar attached to a radioactive isotope (a molecule that spontaneously emits radiation) is injected into the patient’s vein. The cancer cells “take up” the sugar and attached isotope, which emits positively charged, low energy radiation (positrons). The positrons react with electrons in the cancer cells, which creates the production of gamma rays. The gamma rays are then detected by the PET machine, which transforms the information into a picture. If no gamma rays are detected in the scanned area, it is unlikely that the mass in question contains living cancer cells.

Bone Scan: A bone scan is used to determine whether cancer has spread to the bones. Prior to a bone scan, a surgeon injects a small amount of radioactive substance into a vein. This substance travels through the bloodstream and collects in areas of abnormal bone growth. An instrument called a scanner measures the radioactivity levels in these areas and records them on x-ray film.

Next: Limited Small Cell Lung Cancer

Next: Extensive Small Cell Lung Cancer

Next: Recurrent Small Cell Lung Cancer


1 Govindan R, Page N, Morgensztern D et al. Changing epidemiology of small-cell lung cancer in the United States over the last 30 years: analysis of the Surveillance, Epidemiologic, and End Results database. Journal of Clinical Oncology. 2006; 24:4539-44.

2 Shepherd FA, Crowley J, Van Houtte P, et al. The International Association for the Study of Lung Cancer lung cancer staging project: proposals regarding the clinical staging of small cell lung cancer in the forthcoming (seventh) edition of the tumor, node, metastasis classification for lung cancer. J Thorac Oncol. 2007;2:1067-1077