To evaluate the clinicopathologic characteristics and outcome of tumor cells spreading through air spaces in patients with adenocarcinoma of lung / 中华病理学杂志

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.

Alteration of the E-Cadherin/beta-Catenin Complex Is an Independent Poor Prognostic Factor in Lung Adenocarcinoma

BACKGROUND: Epithelial-mesenchymal transition (EMT) is an important step in the invasion and progression of cancer and in the development of chemoresistance by cancer cells. METHODS: To address the clinical significance of the EMT pathway in lung adenocarcinoma and the association of the pathway with histological subtype, we examined 193 surgically resected lung adenocarcinoma samples for the expression of representative EMT-related proteins (E-cadherin, beta-catenin, and vimentin) by immunohistochemistry. Histological subtypes were classified according to the 2011 International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification. The results for EMT-related protein expression were analyzed for correlation with clinicopathological features and with survival. RESULTS: The loss of E-cadherin expression and aberrant beta-catenin expression were significantly associated with larger tumor size, pleural invasion, lymphatic/vascular invasion, and advanced pathological stage (p<0.05). The alteration of the E-cadherin/beta-catenin complex was least frequently observed in the lepidic-predominant group, but these associations were not statistically significant. In the multivariate analysis, altered E-cadherin/beta-catenin complex expression was found to be an independent poor prognostic factor (p=0.017; hazard ratio, 1.926; 95% confidence interval, 1.119 to 3.314). CONCLUSIONS: The alteration of the expression of the E-cadherin/beta-catenin complex was associated with aggressive tumor behavior in lung adenocarcinoma.

Comparison of Direct Sequencing, PNA Clamping-Real Time Polymerase Chain Reaction, and Pyrosequencing Methods for the Detection of EGFR Mutations in Non-small Cell Lung Carcinoma and the Correlation with Clinical Responses to EGFR Tyrosine Kinase Inhibito

BACKGROUND: The aims of this study were to evaluate the abilities of direct sequencing (DS), peptide nucleic acid (PNA) clamping, and pyrosequencing methods to detect epidermal growth factor receptor (EGFR) mutations in formalin-fixed paraffin-embedded (FFPE) non-small cell lung carcinoma (NSCLC) samples and to correlate EGFR mutational status as determined by each method with the clinical response to EGFR tyrosine kinase inhibitors (TKIs). METHODS: Sixty-one NSCLC patients treated with EGFR TKIs were identified to investigate somatic mutations in the EGFR gene (exons 18-21). RESULTS: Mutations in the EGFR gene were detected in 38 of the 61 patients (62%) by DS, 35 (57%) by PNA clamping and 37 (61%) by pyrosequencing. A total of 44 mutations (72%) were found by at least one of the three methods, and the concordances among the results were relatively high (82-85%; kappa coefficient, 0.713 to 0.736). There were 15 discordant cases (25%) among the three different methods. CONCLUSIONS: All three EGFR mutation tests had good concordance rates (over 82%) for FFPE samples. These results suggest that if the DNA quality and enrichment of tumor cells are assured, then DS, PNA clamping, and pyrosequencing are appropriate methods for the detection of EGFR mutations.