['Treatment of patients with idiopathic pulmonary fibrosis (IPF) conventionally includes corticosteroids and cytotoxic agents. No study to date has adequately evaluated the benefits of this approach. This study retrospectively compared combination corticosteroid and cyclophosphamide therapy in a large population of patients who meet the current consensus definition of IPF.', 'Patients were identified retrospectively and treatment addressed on an intention-to-treat basis. Treated and untreated patients were matched by age and percentage of predicted FVC (FVC%) at the time of the initial visit.', 'Two academic tertiary referral centers.', 'The diagnosis of IPF was based on current consensus criteria. A total of 164 patients (82 treated and 82 untreated) were included.', 'Treatment consisted of combined corticosteroid and cyclophosphamide therapy using a standardized protocol.', 'There was no difference in age, FVC%, gender, or smoking status between groups. No survival difference was found between patients who were treated (median survival, 1,431 days) or untreated (median survival, 1,665 days) [p = 0.58]. The lack of treatment effect persisted when only those patients with a diagnosis by surgical biopsy (n = 24) or FVC% >/= 60 (n = 107) were analyzed.'] Does combined corticosteroid and cyclophosphamide therapy alter survival in idiopathic pulmonary fibrosis?