Heterogeneous distribution of PD-L1 expression in the IASLC/ATS/ERS classification of lung adenocarcinoma

Background PD-L1 expression in tumor cells can predict the efficacy of PD-1/PD-L1 inhibitors and prognosis in patients. However, the correlation between the PD-L1 expression and the novel lung adenocarcinoma classification are obscure. Methods 94 lung adenocarcinoma cases were reviewed in the Third Affiliated Hospital of Soochow University from January to December 2019. PD-L1 (DAKO 22C3) was used to test the PD-L1 expression in lung cancer tissue. Result TPS was used to interpret the PD-L1 expression. The negative, low positive and high positive of PD-L1 were 52 cases (55.30%), 29 cases (30.90%) and 13 cases (13.80%). The subtype ratio of acinar, lepidic and solid in adenocarcinoma were correlation with the PD-L1 TPS (r = - 0.37, P < 0.001; r = - 0.22, P = 0.013; r = 0.68, P < 0.001). The results of chi(2) test showed the PD-L1 expression had the significant difference with gender (P = 0.027), age (P = 0.018), smoking history (P = 0.021), lymph node metastasis (P = 0.001), TNM stage (P = 0.002), acinar structure (P = 0.017) and solid structure (P < 0.001). Multi-factor linear regression results suggested that solid structure, TNM stage and smoking history were associated with PD-L1 expression (P < 0.05). The solid structure showed more capability to PD-L1 expression (beta = 0.398). Conclusion PD-L1 expression was heterogeneity in lung adenocarcinoma. The solid structure, TNM stage and smoking history were correlation to up-regulation of PD-L1 expression, and solid structure was the most importance factor.