Complications of lung cancer in the clinical course of interstitial lung disease

Abstract

<b>Introduction:</b> Interstitial lung diseases (ILDs) are associated with the onset of lung cancer (LC). <b>Aims and objectives:</b> We aimed to investigate the incidence rate, time to onset, and risk of the onset of LC in ILD patients. <b>Methods:</b> We retrospectively evaluated consecutive ILD patients in 2008-2015. We investigated whether they developed LC until May 2021. <b>Results:</b> Among 1070 ILD patients, 42 were excluded (patients diagnosed with LC by the time of the diagnosis of ILDs, 23; others, 19) and 1028 were included in the final analysis. Male was 671, median age was 68 years, smoking history was found in 551 (current, 94; former, 457) and 452 were diagnosed as idiopathic pulmonary fibrosis (IPF). The median observation period was 4.88 years (IQR: 2.07-7.49). Sixty-four cases had LC (adenocarcinoma, 25; squamous cell carcinoma, 19; small cell carcinoma, 11; others, 9) and the median time to onset was 3.52 years (95% CI: 2.77-4.32). The incidences of LC were 1.27 cases per 100 person-years (IPF was 1.83 and non-IPF ILDs was 0.94, respectively). Univariable analysis showed male, age, smoking history and IPF were associated with the onset of LC. Multivariable analysis showed male and age were associated. <b>Conclusions:</b> The incidences of LC in ILD patients were 1.27 cases per 100 person-years and the median time to onset was about 3.5 years. Male and age were significantly associated with the onset of LC.