Computed Tomographic Screening for Lung Cancer

Airflow Limitation and Histology Shift in the National Lung Screening Trial. The NLST-ACRIN Cohort Substudy

“…Although this finding requires replication (17,18), our observations argue in favor of the routine use of screening spirometry in asymptomatic smokers at risk of lung cancer either in general (49), or specifically as part of assessing the harm-to-benefit ratio of CT screening (31,33,39). We believe that preselection of eligible smokers for possible CT screening requires greater appraisal as current criteria include many low-risk smokers for whom the harm may substantially outweigh the benefit of screening (25,43,50). The results of this study suggest that overdiagnosis is a significant issue in CT screening for lung cancer and is found exclusively in those with normal lung function at lower risk.…”

“…In the study by Sanchez-Salcedo and colleagues, sensitivity of the eligibility criteria was substantially increased when the presence of airflow limitation or emphysema was added to the current NLST-based eligibility criteria (39). Collectively, these findings suggest that when risk stratifying current and former smokers for their lung cancer risk, variables related to susceptibility to COPD (age, smoking history, self-reported COPD, low body mass index, genetic factors, CT emphysema, or lung function) can be combined to derive a more precise overall lung cancer risk (23,25,38,(42)(43)(44)(45).…”

Reduced Expiratory Flow Rate among Heavy Smokers Increases Lung Cancer Risk. Results from the National Lung Screening Trial–American College of Radiology Imaging Network Cohort

“…In a simulation study, Lowry and colleagues (39) examined the effect of competing causes of death in CT screening participants, and concluded that those with COPD may disproportionately benefit from lung cancer screening. However, some argue that screening patients with COPD may not necessarily translate into mortality benefit due to factors such as competing causes of premature death (40).…”

“…This also suggests that those at greatest risk of lung cancer may not necessarily achieve the greatest benefit from screening (40,42). This is important, because risk models for lung cancer share the same variables associated with COPD (24), often including a past diagnosis of COPD (27,28), or the presence of airflow limitation based on spirometry (29).…”

Is 20% of a loaf enough?

“…This illustrates that, by targeting those at greatest risk, based on several lung cancer risk variables, significant improvements in cost can be achieved without reducing effectiveness. 3 It is noteworthy that these findings strongly refute comments by Bach (see reply to letter by Young et al 3 ) who suggests that targeting smokers at greatest risk may not achieve the desired goal of maximizing the number of lives saved from screening. If our estimates above are correct, then the number needed to screen annually to detect 1 lung cancer reduces from 1 in 152 using National Lung Screening Trial eligibility criteria to 1 in 82 using a multivariate (PLCO) model.…”