Prognostic Impact of the Number of Peritumoral Alveolar Macrophages in Patients With Stage I Lung Adenocarcinoma

Abstract

\n Purpose:Intratumoral macrophages are reportedly involved in tumor progression in non-small cell lung cancer; however, little is known about the prognostic impact and function of alveolar macrophages (AMs). This study aims to investigate the prognostic impact of the number of peritumoral AMs in patients with stage I lung adenocarcinoma.Methods:We investigated 514 patients with pathological stage I lung adenocarcinoma who underwent complete resection with lobectomy or pneumonectomy. The number of peritumoral AMs were counted, and patients were classified into two groups based on the number of peritumoral AMs. Using the Cancer Genome Atlas (TCGA) database of stage I lung adenocarcinoma, we compared gene expression profiles of high and low peritumoral AM contents.Results:The median number of peritumoral AMs per alveolar space was 15.5. Patients with a high peritumoral AM content had significantly shorter disease-free survival and overall survival than patients with a low peritumoral AM content (both p\u2009<\u20090.01). In the multivariate analyses, a higher number of peritumoral AMs was an independent prognostic factor (p\u2009=\u20090.02). The analysis of TCGA database revealed that patients with a high peritumoral AM content had shorter disease-free survival than those with a low peritumoral AM content (p\u2009=\u20090.04). Gene expression analysis of TCGA stage I lung adenocarcinoma revealed enrichment of biological processes, such as chemotaxis and epithelial proliferation, in patients with a high peritumoral AM content.Conclusion:The number of peritumoral AMs had a strong impact on disease-free survival in patients with stage I lung adenocarcinoma.