Spread Through Air Spaces(STAS)in Lung Adenocarcinoma: An Analysis Of 31 Cases And Literature Review

Objective: To investigate the clinical,imaging,pathological features and prognosis of tumor spread through air spaces(STAS)in lung adenocarcinoma.Methods: The clinical data and prognosis of 31 patients STAS in lung adenocarcinoma confirmed by postoperative pathology in our hospital from January 2016 to January 2021 were retrospectively analyzed.Combined with the review of relevant literature,the clinical,imaging,pathological characteristics and prognosis of lung adenocarcinoma STAS were analyzed.Results: 1.General information: there were 19 males and 12 females,with an average age of 58.4 years(38-76 years),including 8 patients with advanced age(>65 years);Smoking 10 cases;Among the 25 patients,6 had clinical symptoms(3had simple cough,1 had cough or expectoration,1 had cough or hemoptysis,and 1had asthma after activity).2.Tumor markers: 8 cases of carcinoembryonic antigen were elevated.3.Imaging features: pulmonary nodules in 21 cases,mass in 10 cases,lobulation sign in 28 cases,burr sign in 21 cases,and pleural pull sign in 19 cases;PET-CT was performed in 5 patients,with the maximum standard uptake of 8.3-14.6.4.Treatment methods: lobectomy in 28 cases,wedge resection in 1 case,pneumonectomy in 1 case.5.Pathological characteristics:(1)Size: Tumor diameter > 2.0cm in 25 patients,with an average diameter of 3.2cm(0.7-7.5cm);(2)Invasion: lymph node metastasis in 13 cases,pleural invasion in16 cases,vascular invasion in 13 cases;(3)TNM stage: 15 patients with stage I and16 patients with stage II-IV;(4)Tumor histological classification: 3 cases of microinvasive adenocarcinoma,27 cases of invasive adenocarcinoma,and 1 case of variation of invasive adenocarcinoma.Among the 27 cases of invasive adenocarcinoma,micropapillary predominant adenocarcinoma(MPA)(7 cases),solid predominant adenocarcinoma(SPA)(9 cases),acinar predominant adenocarcinoma(APA)(10 cases),and lepidic predominant adenocarcinoma(1case).(5)Molecular characteristics: EGFR,ALK,ROS1 and BRAF genes were detected in 22 cases,EGFR mutation was found in 9 cases,ALK rearrangement was found in 3 cases,and ROS1 and BRAF mutations were not found.6.Prognosis: follow-up from 1.2 months to 45.3 months,with a median follow-up time of 11.4 months;28 cases survived and 3 cases died.The overall survival periods of the 3 deaths were 18.2 months,7.8 months and 10.2 months,respectively.Recurrence and metastasis occurred in 5 cases,with a median recurrence-free survival time of 13.8 months.Among them,4 cases were lobectomy(3 cases were MPA,1 case was SPA),and 1 case was wedge resection(APA).Conclusion: 1.CT signs such as lobulation,burr and pleural traction are more likely to appear in STAS in lung adenocarcinoma on imaging.2.STAS in lung adenocarcinoma are common in MPA,SPA,APA,and are more prone to lymph node metastasis and pleural invasion,which may be a more aggressive malignant behavior;3.Lobectomy may be a better option for patients with STAS in lung adenocarcinoma.STAS is closely related to the clinical,imaging,pathological features and prognosis of patients in lung adenocarcinoma,and can be used as a new pathomorphological parameter and prognosis indicator.