Prevalence of cancer in patients with Idiopathic Pulmonary Fibrosis. A retrospective multicenter study

Background: Abundant evidence supports an association between Idiopathic Pulmonary Fibrosis (IPF) and lung cancer development. Nevertheless, epidemiological data on IPF and cancer are scarce. Aim: To estimate prevalence of lung and other types of cancer in patients with IPF. Patients and Methods: This was a retrospective multicenter study, enrolling 608 patients with IPF from six different centers between 2009 and 2018. Results: We identified 63 cases of patients with IPF and cancer (prevalence=10.3%, n=63/608, mean age±SD=72.8±7.5, 57 males, meanFVC±SD= 75.9±21.5, meanDLCO±SD= 47.2±15.8). We recorded 50 cases of lung cancer and 16 patients with other types of cancer (colon n=6, stomach n=2, breast n=2, chronic lymphocytic leukemia n=2, other=4). Three patients had both lung and other type of cancer. Prevalence of lung cancer in patients with IPF was 8.2%. Most cases (74%, n=37) were non-small cell lung cancer (20 squamous, 12 adenocarcinoma, 5 non-specified), while in 7 patients (14%) small cell lung cancer was diagnosed. Primary lesion was localized in upper lobes in 52% (n=26) of cases. In 64%(n=32) of patients, lung cancer was diagnosed post IPF diagnosis (median latency time= 14.6 months), 30%(n=15) of patients were diagnosed with IPF and lung cancer synchronously and 6%(n=3) of cases developed lung cancer prior IPF diagnosis(median latency time=23.8 months). Chemotherapy was applied in 36% of cases, while 20% of patients underwent surgery. Median survival of patients with IPF and lung cancer was 24.0 months (95% CI: 18.6 to 38.0). Conclusions: Our epidemiologic data validates IPF as risk factor for cancer development. Further studies are greatly anticipated.