Objective: To investigate the clinicopathologic features, molecular characteristics and prognosis of spread through air space (STAS) in patients with adenocarcinoma of the lung. Methods: Two hundred and eighty-eight lung adenocarcinoma patients with complete clinicopathologic and follow-up data were included. The patients were divided into STAS positive (178 cases) and negative (110 cases) groups.EGFR and KRAS gene mutations were detected by amplification refractory mutation system (ARMS), and ALK and ROS1 gene fusion were detected by fluorescence in situ hybridization method. The relationship between STAS and clinicopathologic, molecular features, and patient outcome was analyzed. Results: STAS was present in 61.8%(178/288) of lung adenocarcinomas. The positive rate of STAS in tumors >3 cm was significantly higher than that in tumors ≤3 cm (P=0.009), and was significantly higher in tumors with pleural invasion (P<0.01), venous invasion (P<0.01), lymphatic invasion (P<0.01), perineural invasion (P=0.029) and tumors with necrosis (P<0.01). STAS was also correlated with tumor recurrence (P<0.01) and advanced pathologic TNM stage (P=0.002). There was no significant correlation with patients′ gender, age and smoking history. Histologically, STAS was present in 58.0%(91/157), 67.6%(50/74), 2/6, 64.3%(27/42) and 8/9 of acinar, papillary, lepidic, solid and micropapillary adenocarcinomas, respectively. In addition, the positive rates of STAS in tumor with micropapillary (>5%) and without micropapillary pattern were 80.9%(55/68) and 55.9%(123/220), respectively (P<0.01). STAS was significantly higher in EGFR negative group (P=0.034), ALK gene rearrangement group (P=0.003) and ROS1 gene rearrangement group (P=0.012), but there was no significant correlation with KRAS mutation. Univariate survival analysis showed that patients with STAS had a shorter progression-free survival (PFS, P<0.01) and overall survival (P=0.013). Multivariate analysis confirmed that STAS was an independent predictor of PFS in lung adenocarcinoma patients (HR: 2.749, 95%CI: 1.550-4.876, P=0.001). Conclusions The presence of STAS in lung adenocarcinoma suggests high risk of recurrence and invasion and is thus an important prognostic factor. In addition, STAS is associated with EGFR mutation, ALK and ROS1 gene rearrangement.

Hepatocellular carcinoma (HCC) is the most common primary hepatic malign-ancy in clinic. The prognosis of patients remains extremely poor because of the high malignancy and easy recurrence and metastasis of HCC. In recent years, the roles of platelets in promoting the malignant progression of HCC have increasingly attracted much attention. It is known that platelets could promote HCC cells proliferation and invasion through tumor microenvironment. On the other hand, platelets are capable to promote HCC cells distant metastasis by facilitating tumor cells evasion of immune surveillance. Besides, the platelet-derived growth factors and proangiogenic factors are also involved in the proliferation, invasiveness, and neovascularization of HCC. In addition, patients with HCC normally have a background of cirrhosis, and it is still controversial that whether the thrombocytopenia by portal hypertension and hypersplenism can promote the malignant progress of HCC. In view of this, the diagnostic and prognostic value of platelet levels, as well as platelet-associated scores in HCC have increasingly become research focus. The authors elaborate the detailed mechanisms of platelets in malignant progression of HCC, and discuss the recent research progress of platelets as effective diagnostic or prognostic tools for the assessment of HCC, which is of great importance to optimize the current treatment regimen and explore novel therapeutic strategies against HCC.