The role of rapid on site evaluation on touch imprint cytology and brushing during conventional bronchoscopy.

BACKGROUND: The increase in immunohistochemical and molecular predictive tests in lung cancer requires new strategies for managing small samples taken during bronchoscopic procedures. The value of Rapid On Site Evaluation (ROSE) during conventional bronchoscopic procedures on endobronchial neoplasms in optimizing small biopsies and cytologlogical tissue specimens for diagnostic testing, and ancillary studies was evaluated. METHOD: ROSE on touch imprint cytology (TIC) and brushing was performed on 690 consecutive cases of patients undergoing biopsies, using fiber optic bronchoscopy. Immunohistochemical assay for PD-L1, ALK, and ROS1 and molecular testing, via next generation technique for EGFR, KRAS, and BRAF, were performed. RESULTS: The concordance between ROSE and final diagnoses was almost perfect for brushing (sensitivity: 0.84; specificity: 0.96), and less so for touch preparations (sensitivity: 0.77; specificity: 0.89). Immunohistochemical assay for PD-L1 was evaluated on 256 bioptic cases with only six unsuitable samples. Material available for immunohistochemistry for ALK was sufficient in 151 biopsies with no inadequate cases. ROS1 was evaluated in 132 biopsies, with only two unsuitable samples. Molecular analysis was performed on 128 biopsies, 29 TIC, and 17 brushing. Out of these, only ten were considered to be unsuitable. CONCLUSIONS: ROSE is an effective procedure for monitoring the quality and quantity of material taken during conventional bronchoscopic procedures for evaluating the suitability of small samples that must undergo immunohistochemical and molecular assay.

KRAS-Driven Lung Adenocarcinoma and B Cell Infiltration: Novel Insights for Immunotherapy.

Non-small-cell lung cancer, histologically classified into adenocarcinoma (AD) and squamous cell carcinoma, is one of the most deadly malignancies worldwide. Lung AD (LUAD) could benefit of a plethora of target therapies and, in the last few years, also of immunotherapies. Here we focused on a real-life cohort of LUAD and The Cancer Genome Atlas (TCGA)-LUAD dataset aiming to gain insights into the immune contexture of such a malignancy. We explored the mutational status of 41 genes and the expression of 94 genes, related to immune-checkpoint, inflammation, and stromal microenvironment. Surprisingly, we found that our cohort has a very low mutational burden if we consider our panel as its surrogate. Regarding gene expression data, we identified 31 genes significantly deregulated in tumor tissues compared with a pool of normal samples. Unsupervised hierarchical clustering of the deregulated genes is able to identify two clusters of tumor samples, differently enriched in alterations in actionable genes. In particular, we identified a cluster enriched in patients carrying KRAS alterations. In silico deconvolution, that is the inferring of tumor microenvironment composition by gene expression data, through TIMER algorithm has been performed to explore immune microenvironment. Estimation performed on our gene expression matrix showed that B cell infiltration is lower in the KRAS-mutated enriched cluster, as in the TCGA-LUAD dataset. Such a finding has been validated in situ through immunohistochemistry in an independent cohort. Moreover, cases in LUAD-TCGA with low B cell infiltration have a significantly worse overall survival than those with higher levels. In the real-life cohort we observed that cases belonging to cluster enriched in KRAS-mutated patients have a poor outcome. LUAD driven by KRAS mutation represents an unmet clinical need, being refractory to pharmacological inhibition. Our results link KRAS mutations to B cell infiltration. Thus, the present findings could be helpful in a better definition of immunotherapeutic approaches for KRAS mutated patients.