Molecular alterations in non-small-cell lung cancer: Perspective for targeted therapy and specimen management for the bronchoscopist

Recent Developments and Challenges in Molecular-Targeted Therapy of Non-Small-Cell Lung Cancer

Treatment of lung cancer with conventional therapies, which include radiation, surgery, and chemotherapy results in multiple undesirable adverse or side effects. The major clinical challenge in developing new drug therapies for lung cancer is resistance, which involves mutations and disturbance in various signaling pathways. Molecular abnormalities related to epidermal growth factor receptor (EGFR), v-Raf murine sarcoma viral oncogene homolog B1 (B-RAF) Kirsten rat sarcoma virus (KRAS) mutations, translocation of the anaplastic lymphoma kinase (ALK) gene, mesenchymal-epithelial transition factor (MET) amplification have been studied to overcome the resistance and to develop new therapies for non-small cell lung cancer (NSCLC). But, inevitable development of resistance presents limits the clinical benefits of various new drugs. Here, we review current progress in the development of molecularly targeted therapies, concerning six clinical biomarkers: EGFR, ALK, MET, ROS-1, KRAS, and B-RAF for NSCLC treatment.

Handling and standardization of EBUS needle aspiration in NSCLC patients: The value of the cell block, a monoinstitutional experience

BACKGROUND

Lung cancer is the main cause of cancer-related death worldwide, and 85% of all lung tumors are non-small cell lung cancers (NSCLC). More than 60% of all lung tumors are diagnosed at an advanced stage, leading to poor prognosis. Given the growing demand for NSCLC profiling for selection of the most appropriate therapy, the acquisition of adequate tumor samples has become increasingly crucial, mostly in advanced NSCLC patients due to old age and/or comorbidities. Being a mini-invasive sampling technique, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) represents a valuable alternative to traditional transthoracic or surgical sampling in these patients, and perfoming cell block (CB) could be crucial to maximize the potential biological information. The aim of this study is to describe a monoinstitutional interprofessional experience in handling EBUS-TBNA and CB in 464 patients.

METHODS

We retrospectively collected all the consecutive CBs obtained from EBUS TBNA performed between 2014 and 2021 on the lung lesions or mediastinal lymph nodes. All the CBs were handled in a standardized method.

RESULTS

A total of 95.5% (448/464 samples) of adequacy for site and 92.6% (430/464) of adequacy for diagnosis were observed. Moreover, in the adenocarcinoma histotype, ALK, ROS1 and tumor proportion score (TPS) PD-L1 assessment by IHC was possible in 96% (140/146) of cases, and molecular profile was obtained in 93.8% (137/146) of cases. In the squamous cell carcinoma histotype, TPS PD-L1 assessment was possible in 81% (13/16) of cases. All four CB results obtained from carcinoma NOS were adequate for ALK, ROS1 and PD-L1 assessment and molecular profiling. All 39 metastatic samples from extra-pulmonary primary were adequate for immunohistochemical characterization and molecular profiling. Finally, reporting of the tumor sample adequacy to the clinicians took a median time of about 30 h (range: 24-80 h).

CONCLUSION

Careful cytological smear management together with the handling and standardization of CB obtained from EBUS-TBNA could represent an effective method to increase the adequacy of the tumor specimen for both diagnosis and molecular profile.

Which are the limiting factors in lung tissue sampling and diagnostic accuracy for a new Interventional Pulmonology Unit? From expert consensus-based evidence to results of a new-born Unit

Background

There is a gap of knowledge about the factors that may determine the quality and the accuracy of diagnostic bronchoscopic procedures when setting up a new Interventional Pulmonology Unit. As little evidence-based medicine is available on this matter, an online consensus opinion of experts was gathered and compared with real-life data coming from a new Interventional Pulmonology (IP) Unit.

Methods

A survey was emailed to the heads of all Italian IP Units to investigate the factors influencing the success of the diagnostic yield of a new IP Unit. The survey consisted of 24 items grouped by topic; the level of agreement ranged from 1 (no influence) to 7 (strong influence). After responses were collected, we submitted the data on the accuracy of the endoscopic procedures performed during the first two years of our new IP Unit to the attention of the participants for a second round of survey; the level of consistency between the first and second round of responses was assessed.

Results

After having been shown the results of the first two years of activity of our Unit, in the second round of the survey the responders indicated the personal skills of the Interventional Pulmonologist, the availability of echoendoscopic technology and the expertise in evaluating cytological samples as the factors able to positively influence the performance of a newly established IP Unit. Neither the role of dedicated nursing assistance, the availability of a rapid on-site evaluation, nor the presence of anesthesiology assistance were considered to be limiting factors for the final accuracy results.

Conclusions

A consensus of opinion of a group of expert interventional pulmonologists highlighted the factors that may be responsible for the diagnostic success of a newly established Italian IP Unit. These factors are mainly three: personal skills of the interventional pulmonologist, the availability of echoendoscopic technology, and the expertise in reading cytological samples.

PDLIM2 acts as a cancer suppressor gene in non-small cell lung cancer via the down regulation of NF-κB signaling

PDZ and LIM domain containing protein 2 (PDLIM2) has been identified as a vital tumor-associated gene that is aberrantly expressed in various types of tumors. Yet, the involvement of PDLIM2 in non-small cell lung cancer (NSCLC) is currently undetermined. The design of the current study was to evaluate whether PDLIM2 plays a role in NSCLC. We found that PDLIM2 expression was commonly decreased in NSCLC tissues. Moreover, low expression of PDLIM2 was also detected in NSCLC cell lines and demethylation treatment restored PDLIM2 expression. The re-expression of PDLIM2 impeded the proliferative, colony-forming, and invasive capabilities of NCLCL cells. In contrast, depletion of PDLIM2 markedly enhanced the malignant behaviors of NSCLC cells. Notably, PDLIM2 overexpression downregulated the expression of nuclear factor (NF)-κB p65 subunit and repressed NF-κB transcription reporter activity in NSCLC cells. The overexpression of p65 significantly reversed PDLIM2-mediated antitumor effects in NSCLC cells. Additionally, the Xenograft tumor formation assay revealed that the overexpression of PDLIM2 markedly restricted the tumor growth of NSCLC in vivo. Overall, our study confirms that PDLIM2 acts as a tumor-inhibitor in NSCLC through the inactivation of NF-κB, suggesting PDLIM2 as a candidate therapeutic target for NSCLC.

Convex probe endobronchial ultrasound: historical, contemporary, and cutting-edge applications

The use of convex-probe endobronchial ultrasound (CP-EBUS) has revolutionized bronchoscopy. It has provided the option of a relatively safe, minimally invasive approach for the assessment of various intrathoracic diseases. In current practice, its most dramatic impact has been on the diagnosing and staging of lung cancer. It has served as an invaluable tool that has replaced mediastinoscopy in a variety of clinical scenarios. Many pulmonologists and thoracic surgeons consider CP-EBUS the most significant milestone in bronchoscopy after the development of the flexible bronchoscope itself. In this review, we summarize the historical aspects, current indications, technical approach, and future direction of CP-EBUS.

Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for Diagnosis and Staging of Lung Cancer

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS TBNA) is fundamental to the diagnosis of lung cancer, as many patients present with more advanced stages of lung cancer, with enlarged hilar and mediastinal lymph nodes. It also represents a way to sample pulmonary masses directly to make the diagnosis, whereby no other accessible tissue is present and the mass sits adjacent to a large central airway. Very importantly also, EBUS TBNA is the widely accepted first procedure in lung cancer staging. A combined procedure of EUS TBNA can be performed to improve diagnostic accuracy.

Diff-Quik Cytology Smears from Endobronchial Ultrasound Transbronchial Needle Aspiration Lymph Node Specimens as a Source of DNA for Next-Generation Sequencing Instead of Cell Blocks

BACKGROUND

Next-generation sequencing (NGS) in lung cancer specimens from endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is usually performed on formalin-fixed paraffin-embedded cell block material.

OBJECTIVES

Since DNA can be damaged by this process, we investigated the potential of using DNA extracted from Diff-Quik cytology smears made for rapid on-site evaluation during EBUS-TBNA.

METHODS

In a prospective study, 67 patients undergoing diagnostic EBUS-TBNA were ana-lysed. We compared cell blocks and smears for DNA yields and sequencing (TruSeq Amplicon Cancer Panel) outcomes. Smears were also evaluated for tumour cell fraction and overall cellularity (cell count).

RESULTS

Primary lung cancer was diagnosed in 64 patients and metastatic malignancy in 3 patients. The DNA yield from smears was significantly higher than that obtained from matched cell blocks (mean 1,740 vs. 434 ng; p = 0.001). For 33 cases with matched smears and cell blocks the mutation profiles were similar. Smears with abundant malignant cells (using a cut-off of > 25% tumour cell fraction and > 1,000 cells) accurately predicted high (> 50 ng) DNA yield and therefore success in triaging samples to sequencing. In terms of tissue workflow, using only smears as source DNA for sequencing was an improvement in the use of only cell blocks (54/67 [80.6%] vs. 41/67 [61.2%]); however, the use of cell blocks when smears were not available or did not yield sufficient DNA further improved the success rate to 62/67 (92.5%) cases.

CONCLUSION

We recommend smears in laboratory workflows as the primary source of DNA for NGS following an EBUS procedure.

[Progress in Non-invasive Detection of EGFR Mutation in Non-small Cell Lung Cancer]

在过去的十年里，癌症患者的管理模式已经逐渐转向为基于分子突变检测的个体化模式。表皮生长因子受体（epidermal growth factor receptor, EGFR）基因突变是非小细胞肺癌（non-small cell lung cancer, NSCLC）的重要驱动因素，针对EGFR的靶向治疗和传统化疗相比，显示出显著的安全性和有效性。然而，并不是所有的EGFR突变患者都可接受EGFR靶向治疗，不同的突变类型往往预示着不同的临床结局，如敏感性突变EGFR 19-Del、L858R和耐药性突变20ins。此外，如今已经开发出第三代TKI药物Osimertinib（AZD9291）和Rociletinib（CO-1686）可使因EGFR T790M突变，导致初代TKI耐药的患者进一步获益。因此，治疗前了解患者EGFR突变状态，治疗过程中持续监测耐药基因EGFR T790M突变情况，对NSCLC患者靶向药物的管理有着重要的意义。最近几年来，“液体活检”技术得到快速的发展，让我们看到采用非侵入性方法以实时监测耐药性突变成为现实的可能。在本综述中，我们回顾了NSCLC中检测EGFR突变的多种非侵入性检测技术在不同液体样本的临床应用。

Volumetric analysis of intravoxel incoherent motion imaging for assessment of solitary pulmonary lesions

Background Differentiating between malignant and benign solitary pulmonary lesions (SPLs) is challenging. Purpose To determine diagnostic performance of intravoxel incoherent motion-based diffusion-weighted imaging (DW-IVIM) in distinguishing malignant from benign SPLs, using histogram analysis derived whole-tumor and single-section region of interest (ROI). Material and Methods This retrospective study received institutional review board approval. A total of 129 patients with diagnosed SPLs underwent DW-IVIM and apparent diffusion coefficient (ADC). ADC, slow diffusion coefficient (D), fast diffusion coefficient (D*), and perfusion fraction (f) were calculated separately by outlining whole-tumor and single-section ROI. Inter-observer reliability was assessed by inter-class correlation coefficient (ICC). ADC and DW-IVIM parameters were analyzed using independent-sample T-test. Receiver operating characteristic (ROC) analysis was constructed to determine diagnostic performance. Multiple logistic regression was performed to identify independent factors associated with malignant SPLs. Results There were 48 benign SPLs found in 35 patients and 94 patients with lung cancer (LC). ICC for whole-tumor ROI (range, 0.89-0.95) was higher than that for single-section ROI (range, 0.61-0.71). Mean ADC and D were significantly lower in the malignant group. ADC and D 10th showed significantly higher AUC values than did mean ADC and D. D showed significantly higher diagnostic accuracy in mean, 10th, and 25th percentiles than ADC values (all Ps < 0.05). D 10th was found to be an independent factor in discriminating LCs with an odds ratio of -1.217. Conclusion Volumetric analysis had higher reproducibility and diagnostic accuracy than did single-section. Further, compared to ADC, D value differentiated benign SPLs from LCs more accurately.

Comparison of 19-gauge eXcelon and WANG MW-319 transbronchial aspiration needles

Conventional transbronchial needle aspiration (TBNA) using 19‐gauge needles can obtain larger histological specimens for hilar‐mediastinal diagnosis. A new 19‐gauge eXcelon needle was introduced in Taiwan in July 2012. We prospectively enrolled patients with hilar‐mediastinal lesions and pathology results of suspected benign origin or lymphoproliferative processes, to perform TBNA using a 19‐gauge eXcelon needle, between July 2012 and December 2012. The results were compared with historical control of TBNA using a WANG MW‐319 needle between January 2011 and June 2012. The procedure was performed by the same pulmonologist, and rapid on‐site cytologic evaluation was used. The 19‐gauge eXcelon needle was used in nine patients with 15 lymph nodes aspirated, with a mean diameter of 23.3 ± 10.7 mm. The mean number of needle passes was 2.7 ± 1.4, with a diagnostic accuracy of 77.8%. The MW‐319 needle was used in 12 patients with 18 lymph nodes aspirated, with a mean diameter of 21.3 ± 5.7 mm. The mean number of needle passes was 2.2 ± 0.4, with a diagnostic accuracy of 75.0%. Neither technical nor major clinical complications were noted in either group. We concluded that the 19‐gauge eXcelon needle was as safe and effective as the MW‐319 needle. A more adequate specimen could be obtained and fewer needle passes were required with the MW‐319 needle, although the difference did not reach significance.