Lung cancer is a notoriously aggressive disease which has not traditionally been amenable to screening interventions. In August 2011, the results of the National Lung Screening trial were published in the New England Journal of Medicine (http://www.nejm.org/doi/full/10.1056/NEJMoa1102873). This trial gathered 53,454 participants from August 2002 through April 2004 who were considered “high risk” for lung cancer (ages 50-74, > 30 pack year history of smoking) and who then underwent either a low dose chest CT (LDCT) or Chest xray (CXR) annually for three years. The patient population was then followed until 12/31/2009. In the LDCT group, 24.2 % of people had a “positive” result on imaging of which 96.4% were falsely positive. In the CXR group 6.9 % of people had a “positive” result on imaging of which 94.5% were falsely positive. These positive results led to either more follow up imaging or lung biopsy. In the LDCT group, 1060 were found to have lung cancer and were then treated with surgery alone (86%) of some combination or surgery, radiation and/or chemotherapy or observation (14%). In the CXR group, 941 were found to have lung cancer and treated similarly. Note also that 44 lung cancers were subsequently found in LDCT group who had negative screening tests and 137 in the CXR group. This study found that with LDCT compared to CXR (which was chosen as the control over “normal community care” because of the ongoing prostate/lung/ovarian cancer screening trial) lowered the rate of lung cancer deaths by 20%. In order to achieve these results, a small number of procedural complications occured from blood transfusions to lung structural and infectious complications to death. Whether this reduction in the lung cancer death rate was real or related to the “healthy volunteer effect” or lead time bias is an ongoing subject of debate. An Annals of Internal Medicine article addresses the controversy (http://www.annals.org/content/early/2011/09/02/0003-4819-155-8-201110180-00364?aimhp). The take home message seems to be that lung cancer screening is still an issue for research institutions and not yet for community practice.
Additional editorial information has been published on this study. While it does appear that ct chest screening does reduce mortality, there are associated false positive results that confound follow up. See the conclusion below from an Annals of Internal Medicine editorial.
Update in General Internal Medicine: Evidence Published in 2011
“Implications: Annual screening of high-risk patients with low-dose CT decreases mortality from lung cancer. Due to potential harms from false-positive results and a lack of cost-effectiveness data (especially in comparison with alternative proven strategies, such as smoking cessation), further research is necessary before widespread use is recommended.”
More on the issue: From Chest 2013; 143(5)(Suppl): 7s-37s
“patients age 55-74 with greater than 30 pack years of smoking history and within 15 years of quitting smoking may benefit from screening” with the following caveats “the optimal duration and frequency is not known” and “only in settings that can deliver the comprehensive care provided to the National Lung Screening Trial participants”…ie it should start in the tertiary medical centers.