Liquid-based cytology specimens for next-generation sequencing in lung adenocarcinoma: challenges and evaluation of targeted therapy.

BACKGROUND: To explore challenges of liquid-based cytology (LBC) specimens for next-generation sequencing (NGS) in lung adenocarcinoma and evaluate the efficacy of targeted therapy. METHODS: A retrospective analysis was conducted on the NGS test of 357 cases of advanced lung adenocarcinoma LBC specimens and compared with results of histological specimens to assess the consistency. The impact of tumor cellularity on NGS test results was evaluated. The utility of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) was collected. Clinical efficacy evaluation was performed and survival curve analysis was conducted using the Kaplan-Meier method. RESULTS: There were 275 TKI-naive and 82 TKI-treated specimens, the mutation rates of cancer-related genes detected in both groups were similar (86.2% vs. 86.6%). The EGFR mutation rate in the TKI treated group was higher than that in the TKI-naive group (69.5% > 54.9%, P = 0.019). There was no significant difference in the EGFR mutation frequency among different tumor cellularity in the TKI-naive group. However, in the TKI treated group, the frequency of EGFR sensitizing mutation and T790M resistance mutation in specimens with < 20% tumor cellularity was significantly lower than that in specimens with ≥ 20% tumor cellularity. Among 22 cases with matched histological specimens, 72.7% (16/22) of LBC specimens were completely consistent with results of histological specimens. Among 92 patients with EGFR-mutant lung adenocarcinoma treated with EGFR-TKIs in the two cohorts, 88 cases experienced progression, and the median progression-free survival (PFS) was 12.1 months. CONCLUSIONS: Cytological specimens are important sources for gene detection of advanced lung adenocarcinoma. When using LBC specimens for molecular testing, it is recommended to fully evaluate the tumor cellularity of the specimens.

Consistency Analysis of Programmed Death Ligand 1 Expression in Non-Small Cell Lung Cancer Between Pleural Effusion and Matched Primary Lung Cancer Tissues by Immunohistochemical Double Staining.

In clinical practice, programmed death ligand 1 (PD-L1) detection is prone to nonspecific staining due to the complex cellular composition of pleural effusion smears. In this study, diaminobenzidine (DAB) and 3-amino-9-ethylcarbazole (AEC) immunohistochemistry double staining was performed to investigate PD-L1 expression in tumor cells from malignant pleural effusion (MPE). MPE was considered as a metastasis in non-small cell lung cancer patients; thus, the heterogeneity between metastatic and primary lung cancer was revealed as well. Ninety paired specimens of MPE cell blocks and matched primary lung cancer tissues from non-small cell lung cancer patients were subjected to PD-L1 and thyroid transcription factor-1(TTF-1)/p63 immunohistochemistry double staining. Two experienced pathologists independently evaluated PD-L1 expression using 3 cutoffs (1%, 10%, and 50%). PD-L1 expression in MPE was strongly correlated with that in matched primary lung cancer tissues (R = 0.813; P < .001). Using a 4-tier scale (cutoffs: 1%, 10%, and 50%), the concordance was 71.1% (Cohen's κ = .534). Using a 2-tier scale, the concordance was 75.6% (1%, Cohen's κ = 0.53), 78.9% (10%, Cohen's κ = 0.574), and 95.6% (50%, Cohen's κ = 0.754). The rates of PD-L1 positivity in MPE (56.7%) were higher than that in lung tissues (32.2%). All 27 discordant cases had higher scores in MPE. The double-staining method provided superior identification of PD-L1-positive tumor cells on a background with nonspecific staining. In conclusion, PD-L1 expression was moderately concordant between metastatic MPE cell blocks and matched primary lung carcinoma tissues, with variability related to tumor heterogeneity. MPE should be considered to detect PD-L1 when histological specimens are unattainable, especially when PD-L1 expression is >50%. PD-L1 positivity rates were higher in MPE. Double staining can improve PD-L1 detection by reducing false-negative/positive results.

Immunocytochemical detection by a fully automated immunostainer for assisting subclassification of pulmonary tumors on ThinPrep slides in real-life clinical samples: A single-institution experience.

INTRODUCTION: This study aims to investigate the feasibility and reliability of ThinPrep slides in detecting the subclassification of lung cancer and develop a process for immunocytochemistry (ICC) with optimized staining steps of an automated immunostainer. METHODS: Cytomorphology and ancillary ICC by automated immunostainer on ThinPrep slides were performed to subclassify 271 cytology cases of pulmonary tumor, which were stained with 2 or more of the following antibodies: p40, p63, thyroid transcription factor-1 (TTF-1), Napsin A, synaptophysin (Syn), and CD56. RESULTS: The accuracy of cytological subtyping was improved from 67.2% to 92.7% (p < .0001) after ICC. The accuracy of cytomorphology combined with ICC results for lung squamous-cell carcinoma (LUSC), lung adenocarcinomas (LUAD), and small cell carcinoma (SCLC) was 89.5% (51 of 57), 97.8% (90 of 92), and 98.8% (85 of 86), respectively. The sensitivity and specificity of 6 antibodies were as follows: p63 (91.2%, 90.4%) and p40 (84.2%, 95.1%) for LUSC, TTF-1(95.6%, 64.6%) and Napsin A (89.7%, 96.7%) for LUAD and Syn (90.7%, 60.0%) and CD56 (97.7%, 50.0%) for SCLC, respectively. P40 expression on ThinPrep slides had the highest agreement (κ = 0.881) with immunohistochemistry (IHC) results, followed by p63 (κ = 0.873), Napsin A (κ = 0.795), TTF-1 (κ = 0.713), CD56 (κ = 0.576), and Syn (κ = 0.491). CONCLUSION: The result of ancillary ICC on ThinPrep slides by fully automated immunostainer was in good agreement with the gold standard in pulmonary tumors subtype and immunoreactivity, objectively achieving accurate subtyping in cytology.

Imbalance in mitochondrial dynamics induced by low PGC-1α expression contributes to hepatocyte EMT and liver fibrosis.

An imbalance in mitochondrial dynamics induced by oxidative stress may lead to hepatocyte epithelial mesenchymal transition (EMT) and liver fibrosis. However, the underlying molecular mechanisms have not been fully elucidated. This study investigated the role of mitochondrial dynamics in hepatocyte EMT and liver fibrosis using an in vitro human (L-02 cells, hepatic cell line) and an in vivo mouse model of liver fibrosis. Findings showed that oxidative stress-induced mitochondrial DNA damage was associated with abnormal mitochondrial fission and hepatocyte EMT. The reactive oxygen species (ROS) scavengers apocynin and mito-tempo effectively attenuated carbon tetrachloride (CCl4)-induced abnormal mitochondrial fission and liver fibrosis. Restoring mitochondrial biogenesis attenuated hepatocyte EMT. Oxidative stress-induced abnormal hepatocyte mitochondrial fission events by a mechanism that involved the down regulation of PGC-1α. PGC-1α knockout mice challenged with CCl4 had increased abnormal mitochondrial fission and more severe liver fibrosis than wild type mice. These results indicate that PGC-1α has a protective role in oxidative stress-induced-hepatocyte EMT and liver fibrosis.