Bottom line: Low-dose CT screening is associated with a slight (NNT 310) reduction in lung cancer mortality, but uncertainty exists about potential harm of screening.
Summary: JAMA. 2012 May 20:1-12. Benefits and Harms of CT Screening for Lung Cancer: A Systematic ReviewBenefits and Harms of CT Screening for Lung Cancer. Bach PB, et al.
Systematic review of 8 RCTs and 13 cohort studies of LDCT screening that reported lung cancer−specific or all-cause mortality, nodule detection rate, frequency of additional imaging, frequency of invasive diagnostic procedures, or complications from evaluation of suspected lung cancer. RESULTS: 3 RCTs reported lung cancer mortality. The control in one study was chest radiograph and the control in the other two studies was usual care. Table 3 summarizes rates of lung cancer mortality and all-cause mortality (N>30,000).
The NLST study (n >53,000) found that 3 annual rounds of screening (baseline and 1 and 2 years later) with LDCT would require 310 individuals to participate in screening for the t 3 rounds in order to prevent 1 lung cancer death.
The ongoing DANTE (n=2472) and DLCST studies randomized patients to 5 annual rounds of LDCT screening or usual care. A median follow-up of 34 and 58 months of follow-up, respectively, showed no statistically significant difference in lung cancer mortality DANTE: relative risk, 0.97, P = .84; and DLCST: RR, 1.15, P = .43).