[Analysis of Clinicopathological Features on Spread Through Air Spaces
of Lung Adenocarcinoma]

The biological and molecular characteristics of spread through air spaces (STAS), a newly recognized invasive mode of lung cancer, remain controversial. The aim of this study was to investigate the clinicopathological features and molecular characteristics of STAS in patients with pulmonary adenocarcinoma.

A total of 694 resected invasive non-mucinous lung adenocarcinomas diagnosed by clinicopathology from July 2019 to March 2021 in the First Affiliated Hospital of Guangzhou Medical University were collected, and the relationship between STAS and clinicopathological factors was analyzed. The state of protein expression of anaplastic lymphoma kinase (ALK) was detected by immunohistochemical method. Epidermal growth factor receptor (EGFR) was detected by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). ROS proto-oncogene 1-receptor (ROS1) was detected by reverse transcription-PCR (RT-PCR).

A total of 344 STAS positive cases and 350 STAS negative cases were collected. By univariate analysis, STAS positivity was statistically associated with tumor maximum diameter (P<0.001), pleural invasion (P<0.001), lymphovascular invasion (P<0.001), nerve invasion (P=0.013), lymph node metastasis (P<0.001), clinical stage (P<0.001) and histological type (P<0.001). There was a statistical correlation between STAS and ALK protein expression (P=0.001). Multivariate analysis showed that STAS positive was correlated with pleural invasion (P=0.001), vascular invasion (P<0.001), lymph node metastasis (P=0.005)and ALK protein expression (P=0.032).

STAS is associated with highly aggressive biological behavior of lung adenocarcinoma, suggesting a poor prognosis.