Impact of Lung Biopsy Information on Treatment Strategy of Patients with Interstitial Lung Diseases

Rationale: Lung biopsy (LBx) has a relevant role in the prediction of prognosis of interstitial lung diseases (ILDs), but its impact on the clinical management of patients remains unexplored. Objectives: This study evaluates whether LBx may change the therapeutic strategy and assesses the effect of diagnostic reclassification after LBx on long-term prognosis. Methods: We evaluated the LBx of 426 consecutive patients with ILDs, without a definite usual interstitial pneumonia pattern on high-resolution computed tomographic imaging. A total of 266 patients underwent transbronchial lung cryobiopsy (TBLC), and 160 patients underwent surgical lung biopsy (SLB). The multidisciplinary team(MDT) determined a diagnosis with high or low confidence, and a management strategy, both before and after the LBx data. Results: FinalMDT diagnoses were 189 idiopathic pulmonary fibrosis (IPF), 143 non-IPF fibrotic ILDs, and 94 nonfibrotic ILDs. LBx data changed themanagement strategy in 145 cases (34%), with similar results for TBLC and SLB (the treatment strategy changed in 31.5% of TBLC cases, 84/266, P<0.001, and in 38% of SLB, 61/160, P<0.001). After LBx, theMDT was less inclined to "wait and see"(from15% to 4% of cases, P<0.001) or to prescribe steroids only (from54% to 37%, P<0.001) and wasmore confident to treat with antifibrotics (from 23% to 44%, P<0.001) or immunosuppressive drugs (from 7% to 14%, P<0.001). The therapeutic strategy changed in 70% of reclassified cases (60/85) and in 59% of cases in which LBx increased theMDT confidence (84/142). Reclassification significantly impacted the outcome. The cases classified as non-IPF by clinician and radiologist and then reclassified to be IPF after LBx showed a significantly worse survival compared with non-IPF confirmed cases (adjusted hazard ratio [HR], 3.8; 95% confidence interval [CI], 1.75-8.3); P = 0.001. Cases initially classified as IPF and then reclassified as non-IPF after LBx showed a better prognosis compared with IPF confirmed cases (HR, 0.41; 95% CI, 0.18-0.94; P = 0.03). Conclusions: Reclassification of cases with LBx data increased diagnostic confidence and changed the therapeutic strategy in one-third of cases. Pathologic reclassification of cases refined prognosis prediction. Patients classified as non-IPF by clinician and radiologist and then reclassified IPF after LBx had worse prognosis compared with the non-IPF confirmed cases.