New lung cancer screening could help at risk workers
January 11, 2011
A new type of lung cancer screening may help workers who are at increased risk for the disease because of past occupational exposures, according to the National Institute of Occupational Safety and Health.
A posting on NIOSH's Science Blog by Simone Tramma, MD, MS; Eileen Storey, MD, MPH; Douglas B. Trout, MD, MHS; Marie Haring Sweeney, PhD, MPH notes that efforts to detect lung cancer in its early stages, thus improving the survival rates of those diagnosed, have been largely unsuccessful. Lung cancer is the foremost cause of death from cancer in the United States, leading to nearly 160,000 deaths in 2006 (USCS). Annually, nearly 200,000 people have a new diagnosis of lung cancer.
According to the blog, a recent study of a relatively new form of screening using helical computerized tomography (CT) is giving scientists new hope. The study demonstrated fewer lung cancer deaths among individuals at high risk of lung cancer who received this screening than among a similar group screened with chest radiography (chest x-rays or CXRs).
The National Lung Screening Trial (NLST) compared the effects of the two screening procedures in reducing lung cancer mortality in current and former heavy smokers aged 55 to 74.
NLST researchers found 20.3% fewer lung cancer deaths among those who were screened with low-dose helical CT compared with those who were screened with chest x-rays. Preliminary results also showed that among individuals screened with CT, 24.2% had a finding that could indicate the presence of a lung cancer ("positive screen"). In contrast, 6.9% of those screened with CXR had such a finding. CT screening detected 649 cancers out of 18,149 positive screens (3.6%) while CXR screening detected 279 cancers out of the 5,044 positive screens (5.5%). Not all lung cancers were detected by the screening process. In addition, deaths from all causes were 6.9% lower in those who received the low-dose helical CT scans
The NIOSH writers stressed that the data derived from the NLST was obtained from a very specific population group heavy smokers, aged 55 to 74, and that using the screening test for "occupationally exposed" groups requires a careful assessment of the risks of the CT scans (ie., radiation exposure) and the actual exposures.
Complete findings are expected to be published in the spring of 2011.