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. Objective This study evaluates whether LBx may change the therapeutic strategy and assess the effect of diagnostic reclassification after LBx on long term prognosis. Methods We evaluated LBx of 426 consecutive patients with ILDs, without a definite usual interstitial pneumonia (UIP) pattern on high resolution computed tomography (HRCT). 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 Final MDT diagnosis were: 189 IPF, 143 non-IPF fibrotic ILDs and 94 non-fibrotic ILDs. LBx data changed the management 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, the MDT was less inclined to "wait and see" (from 15% to 4% of cases, p<0.001) or to prescribe steroids only (from 54% to 37%, p<0.001), and was more 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 the MDT 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 to non-IPF confirmed cases (adjusted HR 3.8, 95% 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 to IPF confirmed cases (HR 0.41, 95% CI 0.18-0.94; p=0.03). Conclusions Reclassification of cases with LBx data increases 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 to the non-IPF confirmed cases.