Cigarette smoking is the biggest risk factor for lung cancer by far, with current or former smokers making up the vast majority of those with the disease. Fewer people are smoking now, which has led to a reduction in lung cancer. But the disease remains quite common and diagnosis often occurs too late.
Estimated to account for about a quarter of all cancer deaths this year, lung cancer has a greater mortality than any other cancer in both men and women. It causes more deaths than the next three most deadly cancers (colon, breast and prostate) combined.
Avoiding cigarettes, cigars, pipes and second-hand smoke is the best way to prevent lung cancer, and researchers are devising screening protocols to detect malignant and premalignant disease at an early stage.
The National Cancer Institute Trial
From 2002 to 2010, the National Cancer Institute conducted the National Lung Screening Trial to determine the effectiveness of annual CT (computed tomography) scans for lung cancer screening. All study participants were considered high-risk—between 55 to 79 years old, with a smoking history of at least 30 pack-years (a pack-year is one pack of cigarettes per day for one year). More than 50,000 people at 33 centers underwent yearly screening via chest X-ray or low-dose CT scan.
Results showed a 20 percent reduction in lung cancer deaths in the CT group. Furthermore, a 6 percent reduction in mortality from all causes suggests the use of low-dose CT scans is not detrimental, at least in the short term. Subsequently, the United States Preventive Services Task Force and the American Cancer Society approved lung cancer screening in this high-risk population. There is no data to support screening in the general population.
It is important to note that, despite an overall mortality reduction, many lung cancer patients who participated in National Lung Screening Trial did not survive the disease. Therefore, do not consider enrollment in a screening program an excuse to continue smoking. If you are between 55 and 79 years old with at least a 30 pack-year smoking history, discuss the risks and benefits of lung cancer screening with your primary care provider.