Lung cancer is the leading cause of cancer death in the United States. It is responsible for 32 percent of male cancer deaths and a quarter of female cancer deaths in this country. In 2000, 164,100 people will be diagnosed with lung cancer, and 156,900 people will die from the disease. The average age at diagnosis is 60.
Although more men than women develop lung cancer and die from the disease, the proportion of women is rising. From 85 to 90 percent of cases of lung cancer are related to smoking, but fewer than one in five smokers will develop the disease. Scientists are currently investigating why some people are more susceptible to the disease than others; genetic factors are almost certainly responsible.
There are two main types of lung cancer: small-cell lung cancer (SCLC), which accounts for about 20 percent of lung cancers; and non-small-cell lung cancer (NSCLC), a grouping of three types of cancer that makes up the rest. SCLC is much more aggressive, but is chemo-sensitive and is usually treated with chemotherapy or radiation therapy and rarely with surgery; the NSCLCs are less chemo-sensitive, but treated with surgery, radiation and chemotherapy. For specific information on these diseases, see the summaries for NSCLC and SCLC.
The survival rate for lung cancer is very low: 14 percent of whites live five years after diagnoses, while 11 percent of African Americans do. A rare form of lung cancer that strikes the lining of the chest cavity, mesothelioma, is associated with exposure to asbestos. For specific information, see the summary on mesothelioma.
Half of people with lung cancer whose disease is found early and treated with surgery can expect to live for five years, but only 15 percent of cases of lung cancer are diagnosed at this stage. For this reason, the major focus of current lung-cancer research is on early detection.
Researchers hope one day to be able to test patients who are at high risk of lung cancer for certain tumor markers or scan them with imaging tests that would reveal early-stage cancer. Although many potential tumor markers, such as chromosomal abnormalities or chemicals released by pre-cancerous cells, are being studied, none are yet clinically useful for screening patients.
Summer of 1999 brought some promising news on early lung cancer detection. A study of 1,000 smokers and former smokers by Cornell Medical Center researchers (The Lancet 1999:354;99-105) found that a test called helical low-dose CT scanning, which takes 20 seconds, identified small lung tumors that had not yet spread in 23 patients, versus four such cancers identified by a conventional X-ray. The tumors were removed surgically. As of the publication of the report this July, the patients remained cancer-free.
The report's lead author, Dr. Claudia I. Henschke of Cornell Medical Center, says smokers or ex-smokers who recently quit should have the scan annually to screen for lung cancer. It's now up to health-care researchers and policy makers to confirm that the scan is indeed useful as a screening test, and to determine whether health insurance will pay for it. The scan, which costs about $300, is available at a handful of centers around the country.
Copyright © 2000 Oncology.com, Inc. All rights reserved.
