More than 70 percent of tumors diagnosed by the tomographic technique may still be in Stage I disease. The authors note that because spiral tomography detects a high percentage of benign nodules, positron emission tomography scanning should be used to confirm cancer stage because it is more sensitive, specific, and accurate.

In 2001, lung cancer caused more than 1 million deaths worldwide. In the United States, the disease accounts for 28 percent of all cancer deaths each year.

Non-small cell lung cancer accounts for about 80 percent of all lung cancer cases. Because surgical resection or radical radiotherapy can cure only about 10 percent of patients, 90 percent are either diagnosed with advanced disease or have disease progression to the point that the disease is terminal. With current treatment options, early detection is especially important as a possible tool to improve survival.

Small cell lung cancer accounts for about 20 percent of all cases. Because it is sensitive to several chemotherapeutic agents, it is possible to gain a 50 percent or more reduction in tumor size in greater than 30 percent of previously untreated patients. When the disease is diagnosed in limited stage, it is treated by both chemotherapy and chest irradiation. The three-year survival rates for combined treatment have climbed to between 20 and 30 percent.

The authors stress that communities and countries that institute a smoking ban probably can achieve far more in the long term than physicians can with all current diagnostic and therapeutic options.