High Expression of Indoleamine 2, 3-Dioxygenase in Adenosquamous Lung Carcinoma Correlates with Favorable Patient Outcome

Background: Indoleamine 2,3-dioxygenase (IDO), an enzyme involved in tryptophan (Trp) metabolism, is generally considered to be an immunosuppressive molecule. The prognostic role of IDO expression in tumor has not been well studied in non-small cell lung cancer (NSCLC) and even not been reported in adenosquamous lung carcinoma (AdSqLC). Herein, the aim of this study is to investigate the prognostic significance of IDO expression in patients with AdSqLC.