LAUSR

Interstitial lung abnormalities (ILA) are incidentally identified abnormalities on chest computed tomography (CT) consistent with interstitial lung disease (ILD) in an individual without a known or suspected diagnosis. ILA have been associated with many adverse clinical outcomes including significant reductions in lung function, exercise capacity and survival, and in some cases may be a precursor for the most severe forms of ILD—idiopathic pulmonary fibrosis (IPF) and progressive pulmonary fibrosis. ILA are becoming increasingly recognised in clinical practice, which motivated publication of a Fleischner Society Position Paper in 2020 to codify the definition for clinical use and begin to assemble suggestions for realworld management. Lung cancer and ILA are commonly coidentified on chest CT scans, given that both conditions can share some mutual risk factors. 7 There have been several studies demonstrating an increased risk for adverse treatmentrelated consequences in patients with lung cancer with ILA including radiation pneumonitis, immune checkpoint inhibitorinduced pneumonitis, and mortality in general. Although adverse postoperative outcomes are well described in patients with IPF, 11 less is understood about the operative risk of lung cancer resections among those with ILA. For patients to make informed decisions about undergoing a potentially curative lung cancer resection, understanding the added surgical risk of ILA is critical. In their Thorax paper, Im et al investigate the association of adverse surgical outcomes among those with ILA in the setting of lung cancer resection. They utilised a matched casecontrol design that draws from a singlecentre cohort of patients who underwent lung cancer resection and identified 50 patients with ILA on CT that also had histological features suggestive of ILD. They matched those with ILA to 200 controls and 50 patients with IPF who underwent resection based on sex, age, tumour location, the extent of surgery, tumour histology and pathological stage. They noted higher rates of postoperative pulmonary complications (PPCs) and reduced 5year survival rates among those with ILA compared with controls (3% and 76% vs 18% and 52% for PPCs and survival rates, among controls and those with ILA, respectively). The PPCs among those with ILA were made up almost exclusively of prolonged air leak and acute lung injury with 8% of those with ILA having each of the two complications. As expected, the rates of adverse outcomes were higher among patients with IPF compared with those with ILA, although the rate of acute lung injury was relatively similar (8 vs 12% for ILA and IPF, respectively). These data add to previous literature demonstrating that ILA results in substantially increased risks of treatmentrelated adverse outcomes among patients with lung cancer. There are some limitations to the interpretation of these results that are important to note. First, although the addition of histological findings is of interest, restricting the ILA definition to those with additional histological abnormalities limits the generalisability of these findings. While most patients with lung cancer will have imaging prior to a surgical intervention, histopathological specimens sufficient to identify findings consistent with ILD will likely be unavailable preoperatively. Second, while preexisting pulmonary disease was reportedly excluded from the controls (even though 32% of the controls had an FEV1/FVC<70%), this exclusion was not applied to those with ILA. This may limit our ability to interpret the estimates of risk that are attributable to ILA alone. Third, as information about patients with lung cancer who were not deemed to be surgical candidates in each of these groups was not presented, it is unclear how much selection bias might have differentially affected some of the results between groups. Despite these limitations, this study provides important insights into the perioperative risk of lung cancer resection among those with ILA and adds to a growing literature about adverse ILAassociated treatmentrelated outcomes. Future work should focus on riskstratifying patients with lung cancer and ILA, similar to a recent study demonstrating that pulmonary function and radiologic features of fibrosis are helpful in identifying subsets of smokers with ILA most prone to experience adverse outcomes. Comparable analyses in this patient population could enable a better understanding of the factors driving increased surgical complications in ILA and allow for a more effective risk assessment and thus informed decisionmaking for individual patients. In conclusion, the study published by Im et al demonstrates that ILA may increase the risk of adverse outcomes in patients undergoing surgical resection for lung cancer. While ILA is, by definition, an incidental finding, it is not of unknown clinical significance. These findings, in conjunction with others, exhibit the importance of identifying ILA and disclosing these results to patients, so that an informed discussion about the next steps in management can take place. Given that chest CT characterisation is nearly universal among this patient population, it is time to shed light on this entity—systematic reporting and counselling about the risks of ILA should become the standard.