Fibrotic Interstitial Lung Abnormalities on Preoperative CT Images Predict Cause-Specific Mortality after Stage I Non-Small Cell Lung Cancer Resection.

Abstract

Background: Interstitial lung abnormalities (ILAs) and preclinical interstitial lung disease (ILD) are associated with an increased incidence of lung cancer and high mortality. However, their impact on cause-specific mortality following surgical resection of clinical stage I non-small-cell lung cancer (NSCLC) remains unclear. We evaluated the relationship between preoperative ILAs and postoperative mortality in patients with clinical stage I NSCLC who underwent surgical resection.

Methods: In this retrospective study, we included patients who underwent complete resection for clinical stage I NSCLC between 2006 and 2018 and excluded those with ILD. Preoperative computed tomography (CT) images were classified as no ILA, non-fibrotic ILA, or fibrotic ILA.

Results: Of the 704 included patients, 75 (10.6%) had ILAs, including 24 (3.4%) with non-fibrotic ILA and 51 (7.2%) with fibrotic ILA. Patients with fibrotic ILAs were older (median age, 75 years) and predominantly male (88.2%), whereas 629 patients had no ILA (median age, 69 years; male, 49.1%). The 5-year overall survival rates were 90.0%, 71.0%, and 35.1% in patients with no, non-fibrotic, and fibrotic ILAs, respectively (log-rank p < 0.001). Fibrotic ILAs were independently associated with poorer overall survival (hazard ratio [HR] 4.50; 95% confidence interval [CI] 2.86-7.09) and higher mortality (lung cancer-specific: HR 7.64; 95% CI 4.03-14.46; other cause: HR 2.79; 95% CI 1.44-5.42) than no ILAs.

Conclusion: Fibrotic ILAs were associated with increased lung cancer-specific and other-cause mortality after resection for stage I NSCLC, suggesting that fibrotic ILAs, although often subtle on routine CT, may serve as clinically meaningful imaging prognostic markers.