Interventional Chest/Diagnostic Procedures
Complications and economic burden of diagnostic procedures for lung abnormalities in the community setting
The influential National Lung Screening Trial (NLST) reported a 20% reduction in lung cancer-related deaths using low dose CT scan when compared with plain chest radiography (Aberle et al.). Many medical societies responded by recommending screening individuals at high-risk for lung cancer, and community-based lung cancer screening programs were developed across the US. A concerning feature of the study was the rate (23.3%) of false-positive findings after three rounds of screening and the potential for complications secondary to diagnostic invasive procedures.
Using a 2008-2013 cohort of community inpatient and outpatient practice settings, Hou and colleagues searched administrative databases for procedure and diagnostic codes used in the NLST (Hou et al.). The study team created an age-matched control cohort that did not have an invasive procedure and used the difference in complications rates as an indicator of a procedure-related complication. Additionally, they estimated 1-year medical costs associated with complications. More than 340,000 patients were included in the study, and the overall complication rate was far higher than what was reported in the NLST. This difference was more pronounced in the older group in the study cohort (23.8% vs 8.5%). The associated economic burden of complications was substantial, and cost more than the initial procedure itself.
Although this was not a lung cancer screening cohort and used an administrative database, some valuable lessons can be offered from this study. First, complication rates of procedures like those performed in the NLST are likely to be higher in low-volume centers. Second, in order to minimize procedures, associated complications, and costs, we should be cognizant of the diagnostic limitations of each type of intervention when evaluating patients with lung nodules, wisely choosing the correct procedure for the correct patient after multidisciplinary discussion. We should seek to minimize biopsies of lesions that are likely benign. Third, it is evident that more research is needed regarding this topic. The ideal study would need to include both academic and community-based lung cancer screening programs, and, prospectively, analyze the diagnostic yield and complication rates, as well as downstream costs. Finally, the results of this study call all of us to properly follow the lung cancer screening guidelines and reconcile them with our common sense when evaluating a patient with a screen-detected nodule. Injudicious testing invites unnecessary complications, increases the cost of care, and diverts resources from those more likely to benefit from appropriate interventions.
Jose Cardenas-Garcia, MD, FCCP
Steering Committee Member
Douglas Arenberg, MD, FCCP
Pediatric Chest Medicine
microRNAs: A New Biomarker
Biomarkers are essential tools in a clinician’s armamentarium. Biomarkers have multiple uses being indicators of a pathologic or physiologic process. One promising biomarker, now studied across multiple disorders, is microRNA (miRNA).
miRNAs are short (18–22 nucleotide) regulatory RNAs that bind mRNAs and decrease protein translation. miRNAs are generally co-transcribed with neighboring genes or co-transcribed within a cluster of miRNAs (a polycistronic cluster). Over 2,000 miRNAs are listed on miRBase (), considered the central repository.
Function and biomarker utility of miRNAs are specific to the cells in which they are expressed. miRNAs isolated from circulating plasma exosomes have been shown to be stable over time, which is key in establishing their utility (Sanz-Rubio, et al.).
miRNAs have been credited with the function of micromanaging the circadian clock and sleep homeostasis in virtually all living organisms (Goodwin, et al.; Mehta, et al. ).
Preliminary work has identified dysregulated miRNAs in patients with obstructive sleep apnea (Li, et al.). Exosomal miRNA has been shown to predict and protect against severe bronchopulmonary dysplasia (Lal, et al. ).
Circadian miRNAs in salivary samples were found to have “altered” expression in autistic children with disordered sleep relative to peers with typical sleep (Hicks, et al.). Collection from salivary samples facilitates multiple timed collection feasible at home and has multiple benefits.
Work on miRNAs, though preliminary, appears promising in providing a much-needed new perspective on pathophysiology and treatment in many disease processes.
Harish Rao, MD
Steering Committee Member