Prognostic Significance of Histopathologic Subsets in Idiopathic Pulmonary Fibrosis

TLDR

Idiopathic pulmonary fibrosis is a generally fatal disorder with a median survival of 3 to 6 years, based on limited studies with inconsistent biopsy confirmation. The study aimed to determine overall survival rates, histopathological subgroups, and their prognostic significance in IPF patients. A retrospective analysis of 104 IPF patients (54 men, 50 women, median age 63) who underwent open lung biopsy at Mayo Medical Center between 1976 and 1985 reviewed heterogeneous histopathology including UIP, DIP, NSIP, AIP, bronchiolitis, BOOP, and others. Median overall survival was 3.8 years (10‑year survival 27 %), with the UIP subgroup surviving only 2.8 years—significantly worse than other chronic interstitial pneumonia subtypes—underscoring that accurate histopathologic classification is essential for prognostication.

Abstract

Idiopathic pulmonary fibrosis (IPF) is a generally fatal disorder with a reported median survival of 3 to 6 yr. This has been based on relatively few studies with diagnoses inconsistently confirmed by adequate lung biopsy. Retrospective analysis of 104 patients with IPF who had open lung biopsy (OLB) at Mayo Medical Center from 1976 to 1985 was performed to establish the overall survival rate, the spectrum of histopathological subgroups and their associated prognostic significance. The study group consisted of 54 men and 50 women with a median age of 63 yr. Median survival was 3.8 yr after diagnosis by OLB with an estimated 10 yr survival of 27%. Current histopathologic review showed a heterogeneous group including usual interstitial pneumonia (UIP), desquamative interstitial pneumonia (DIP), nonspecific interstitial pneumonia/fibrosis (NSIP), acute interstitial pneumonia (AIP), bronchiolitis, bronchiolitis obliterans organizing pneumonia (BOOP), and others. Median survival of the UIP group was 2.8 yr which is significantly worse (p < 0.001) than for other subgroups of chronic interstitial pneumonias. IPF includes several histopathologic subgroups with significantly different survival rates. Patients with UIP have worse survival than patients with other types of idiopathic chronic interstitial pneumonias including NSIP. Accurate histopathologic classification is essential for prognostication in patients with IPF.