146 / 2019-11-14 20:59:06

Is low-dose computed tomography the most effective strategy for screening lung cancer? A systematic review and network meta-analysis

lung cancer,screening,low dose computed tomography,systematic review,network meta analysis

B. 公共卫生相关主题 > Track - B 默认专题

Background and aims: Lung cancer is one of the commonest forms of cancer and is the major cause for cancer-related death worldwide. Early diagnosis of lung cancer through effective screening strategies could be considered as a key solution reducing disease burden from lung cancer. Evidence has suggested that low dose computed tomography(LDCT) scans showed promising results in reducing both lung cancer mortality and all-cause mortality when compared with chest radiography among the risk population. However, conflicts results were reported from trials compared LDCT with that of usual care or no screening. We conducted a systematic review and network meta-analysis by collected all the available comparisons for exploring whether LDCT is the most effective choice for screening lung cancer.
Methods: We searched randomized controlled clinical trials (RCTs) from the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed and EMBASE(Ovid), from inception till October 2019 with no language restrictions. Any RCTs compared the effectiveness of LDCT with any other screening methods or usual care/no screening in reducing mortality were considered eligible. Network meta-analysis was used to compare the comparative effect of different screening strategies and to explore whether LDCT is the most effective choice for screening lung cancer in terms of reducing mortality. The risk of bias among included RCTs was assessed using the Cochrane Risk of bias tool for randomized controlled trials version 2 (RoB2).
Results: Eight RCTs with a total of 242,449 participants were included. Results from meta-analysis showed that: LDCT had neither significant benefits in reducing lung cancer mortality when comparing to usual care (pooled RR=0.88, 95%CI:0.71 to 1.01; I2=18.2%, p=0.3; 4 RCTs) nor in reducing all-cause mortality (pooled RR=0.96, 95%CI:0.90 to 1.02; I2=0.0%, p=0.74; 6 RCTs). One RCT compared LDCT with chest X-ray(CXR) showed a relative reduction of 20% (RR=0.80 ,95% CI:0.70 to 0.92) in lung cancer mortality and a statistically significant relative reduction of 6% (RR=0.94 , 95% CI:0.88 to 0.998) in all-cause mortality over a follow-up of 7.4 years; one RCT compared CXR with usual care showed no significant difference in reducing lung cancer mortality (RR=0.95, 95%CI:0.87 to 1.04) and in reducing all-cause mortality (RR=0.98, 95%CI:0.96 to 1.01) for over 10 years. By combining both direct and indirect evidence, network meta-analysis showed that LDCT screening significantly reduced lung cancer mortality [pooled RR=0.77, 95%CI:0.68 to 0.88, 95% predictive interval(PrI):0.58 to 1.03] and all-cause mortality (RR=0.93, 95%CI:0.88 to 0.99, 95%PrI:0.86 to 1.01) when compared to that of usual care. LDCT screening significantly reduced lung cancer mortality (RR=0.81, 95%CI:0.72 to 0.91, 95%PrI :0.63 to 1.05) when compared to CXR, however, no significant difference in reducing all-cause mortality was observed between LDCT vs CXR. Sensitivity analysis of network meta-analysis revealed that the reduction in all-cause mortality is not stable when compared LDCT with usual care (RR=0.95, 95%CI:0.88 to 1.02). Consistency assessment showed that the direct and indirect evidence sources are consistent in lung cancer mortality and all-cause mortality.
Conclusion: LDCT can significantly reduce all-cause mortality when compared with usual care in screening lung cancer, however, this result is not stable, LDCT can also significantly reduce lung cancer mortality when compared with usual care, which may be overturned by future evidence.