Screening for Lung Cancer with Low-Dose CT

Screening for Lung Cancer with Low-Dose CT

Lung cancer causes more deaths among American men and women than any other type of cancer. There will be an estimated 159,000 lung cancer deaths in 2014, according to projections from the American Cancer Society.

However, as the results of a recently completed clinical trial show, many of these deaths could be prevented if high-risk individuals were provided annual low-dose computed tomography (CT) screening for lung cancer. This preventive service is now recommended by the American Cancer Society, the American Society of Clinical Oncology and the U.S. Preventive Services Task Force (USPSTF) for certain patient populations.

Statistics on Lung Cancer and Smoking

The health risks associated with smoking pose a major public health concern and efforts to educate the general public about these risks, as well as to limit the marketing and sale of tobacco products, have had an effect. While lung cancer mortality rates reached all-time highs in 1990 among men and in 2003 among women, these numbers are now in decline among both groups, according to the Centers for Disease Control and Prevention. Additionally, more than 1 in 3 people were smokers in 1975 compared to fewer than 1 in 5 today.

While these statistics indicate progress, more than 94 million current or former smokers are living in the U.S. and many of these individuals are at high-risk for developing a smoking-related health condition, such as lung cancer. According to the American Cancer Society ‘Cancer Facts & Figures 2014’ report:

1. Approximately 224,210 new lung cancer cases will be diagnosed in 2014.

2. Nearly one-third of all cancer deaths can be attributed to smoking.

3. Nearly 9 out of 10 lung cancer deaths can be attributed to smoking.

4. Around 14 percent of all cancers are associated with smoking.

The National Lung Screening Trial Tests Low-Dose CT

One of the largest clinical trials ever funded by the National Institutes of Health, the National Lung Screening Trial (NLST) investigated the use of low-dose CT in screening for lung cancer. More than 53,000 patients were studied. Each was between the ages of 55 and 80, and had a 30 pack-year smoking history (i.e. one packer per day for 30 years or two packs per day for 15 years).

Patients received three rounds of annual screening during the study, with one-half receiving standard chest X-ray and the reset receiving low-dose chest CT. There were a total of 941 lung cancers diagnosed and 443 lung cancer deaths among patients receiving standard X-ray compared to 1,060 lung cancers diagnose and 356 lung cancer deaths among patients.

These results, published August 2011 in New England Journal of Medicine, show that screening for lung cancer with low-dose CT was associated with a 20 percent decrease in lung cancer mortality.

Screening for Lung Cancer: New Guidelines

Since NLST results were publicized, several advisory panels and professional associations have issued new guidelines recommending annual low-dose CT to screen for lung cancer.

The USPSTF, for instance, recommends annual low-dose chest CT in adults aged 55 to 80 who have a 30-pack-year history and who are still smoking or have quit within the past 15 years. Lung cancer screening recommendations resembling those of the USPSTF have also been issued by the American Cancer Society, American Society of Clinical Oncology, American College of Radiology and American Lung Association.

Screening for lung cancer with low-dose CT can help to save lives, as the results of the NLST indicate. To meet the needs of patients who would benefit, Valley Radiology Centers will offer low-dose CT lung cancer screening at our imaging centers throughout the South Bay and Peninsula region.