Analysis Of Tumor Spread Through Air Spaces In The Clinicopathological Characteristics Of Non-small-cell Carcinoma

Objective:This study is based on the 8th edition AJCC/UICC staging system,researched the correlation between the spread through air space(STAS)and the clinicopathological features of non-small cell lung cancer(NSCLC),including surgical approaches,characteristics of cancer-targeted genes,immunohistochemical expression,and other factors.And explored the reasons for the formation in STAS in non-small-cell-lung-cancer.Materials and Methods: The patients with NSCLC who underwent radical excision within 2020 were retrospectively analyzed,as the subjects for collecting the data such as clinical medical records,postoperative pathological specimens,and targeted-drug-gene test reports of 251 patients who diagnosed as stage I,II,and III according to the 8th edition of AJCC/UICC staging system.The subjects were divided into the STAS group and the non-STAS group based on whether the tumor spread through the air space(STAS)observed in the pathology reports of paraffin sections issued by the pathologists of our hospital.SPSS25.0 software was used for data analysis.The relationship between STAS of NSCLC and clinicopathological features,molecular features of targeted genes and other factors was tested with univariate and multivariate analysis by using Cox proportional risk regression model,Logistic regression analysis and other methods.Results: A total of 251 patients with NSCLC were included in the study.Among them,there were 219 patients in the non-STAS group,25 patients in the STAS group,and seven patients without reporting STAS.The distribution of STAS was as follows: 9.5%(19/198)with lung adenocarcinoma,10.52%(4/38)with lung squamous carcinoma,33.3%(1/3)with adenosquamous carcinoma,and 33.3%(1/3)with pulmonary neuroendocrine carcinoma.The results showed that: 1.The probability of tumor spreading through the air space(STAS)in patients with NSCLC has no correlation with the patients’ gender,age,smoking history,preoperative tumor markers,surgical approach,intraoperative excision site and range,etc.2.Compared with other lung cancer growth patterns,STAS is very common in patients with micropapillary components(19.75%,P=0.131)in lung adenocarcinoma,who were detected PD-L1 gene mutations in tumortargeted genes.It is related to the progression of pathological N staging(p<0.001)and the aggressive imaging features of tumors(P=0.02).In the multivariate model,it was found that the growth pattern of lung cancer with micropapillary pathological components(OR =4.706,95% CI = 1.830～12.104,p = 0.001),pathological N staging(OR = 4.379,95% CI = 1.501～ 12.779,p = 0.007)and high-aggressive imaging features of CT(burr sign,lobular sign,pleural traction,sulcus sign)(OR=4.088,95%CI=1.364～12.255,P=0.012)are independent predictors of STAS.Conclusions: 1.The theory that STAS is a pathological illusion formed by manual operation during surgery is not supported by this study.2.The presence of STAS is positively correlated with aggressive features of CT scan images,tumor N staging,pathological examinations indicating micropapillary components,and the detection of positive PD-L1 gene mutations in tumor-targeted genes,which can be regarded as independent risk factors for STAS occurs.