Prognostic significance of alveolar collapse in lung invasive adenocarcinoma and its relationship with tumor infiltrating lymphocytes.

This study aims to investigate the correlations between alveolar collapse, tumor size, and tumor infiltrating lymphocytes (TILs), while also evaluating the prognostic significance of alveolar collapse in invasive lung adenocarcinoma. 355 patients with solitary invasive lung adenocarcinoma were divided into two groups based on the maximum diameter of alveolar collapse: alveolar collapse ≤ 5 mm group and alveolar collapse > 5 mm group. Differences in clinicopathological characteristics, tumor size, TILs, and prognosis were compared between the two groups. The alveolar collapse > 5 mm group had a higher mean age, larger tumor diameter, and increased TILs levels compared to the alveolar collapse ≤ 5 mm group (P < 0.05). A moderate positive correlation was observed between alveolar collapse and tumor size (r = 0.646, P < 0.001). Lung adenocarcinoma with alveolar collapse > 5 mm demonstrated superior 5-year survival and acted as an independent prognostic indicator (HR=0.152, P = 0.004) in multivariate Cox regression analysis, alongside tumor size (HR=10.172, P = 0.034) and lymph node metastasis (HR=2.88, P = 0.017). The size of alveolar collapse is associated with TILs abundance, suggesting that the immune microenvironment may play a crucial role in alveolar collapse formation. Pathologists should take note of alveolar collapse in lung adenocarcinoma.