Multi-gene analyses from waste brushing specimens for patients with peripheral lung cancer receiving EBUS-assisted bronchoscopy

Comparison of Ultra-Magnifying Endocytoscopic and Hematoxylin-Eosin-Stained Images of Lung Specimens

Endocytoscopy enables real-time observation of lesions at ultra-magnification. In the gastrointestinal and respiratory fields, endocytoscopic images are similar to hematoxylin-eosin-stained images. This study aimed to compare the nuclear features of pulmonary lesions in endocytoscopic and hematoxylin-eosin-stained images. We performed an endocytoscopy to observe resected specimens of normal lung tissue and lesions. Nuclear features were extracted using ImageJ. We analyzed five nuclear features: nuclear number per area, mean nucleus area, median circularity, coefficient of variation of roundness, and median Voronoi area. We conducted dimensionality reduction analyses for these features, followed by assessments of the inter-observer agreement among two pathologists and two pulmonologists to evaluate endocytoscopic videos. We analyzed the nuclear features of hematoxylin-eosin-stained and endocytoscopic images from 40 and 33 cases, respectively. Endocytoscopic and hematoxylin-eosin-stained images displayed a similar tendency for each feature, despite there being no correlation. Conversely, the dimensionality reduction analyses demonstrated similar distributions of normal lung and malignant clusters in both images, thus differentiating between the clusters. The diagnostic accuracy of the pathologists was 58.3% and 52.8% (κ-value 0.38, fair), and that of the pulmonologists was 50% and 47.2% (κ-value 0.33, fair). The five nuclear features of pulmonary lesions were similar in the endocytoscopic and hematoxylin-eosin-stained images.

Bronchoscopic tissue yield for advanced molecular testing: are we getting enough?

The treatment of advanced lung cancer has become increasingly personalized over the past decade as a result of the improved understanding of tumor molecular biology and anti-tumor immunity. An adequate tumor sample is central to targetable mutation analysis, and immunologic profiling. The majority of lung cancer patients currently present at an advanced disease stage, so that diagnosis and staging are largely based on small biopsy and cytology specimens. Flexible bronchoscopy techniques play a prominent role in the acquisition of these diagnostic specimens. This narrative review summarizes the available evidence with regards to the role of various conventional and advanced flexible bronchoscopy techniques in acquiring sufficient tissue for mutation analysis and programmed death-ligand 1 (PD-L1) testing.

Adequacy of Samples Obtained by Endobronchial Ultrasound with Transbronchial Needle Aspiration for Molecular Analysis in Patients with Non-Small Cell Lung Cancer. Systematic Review and Meta-Analysis

RATIONALE

Endobronchial ultrasound and transbronchial needle aspiration (EBUS-TBNA) are commonly used for the diagnosis and mediastinal staging of lung cancer. Molecular markers are becoming increasingly important in patients with lung cancer to define targetable mutations suitable for personalized therapy, such as epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), reactive oxygen species proto-oncogene (ROS1), and programmed death-ligand 1 (PD-L1).

OBJECTIVES

To evaluate the adequacy of EBUS-TBNA-derived tissue for molecular analysis.

METHODS

We searched the MEDLINE, LILACS, www.clinicaltrials.gov , and Epistemonikos databases through January 2018.

DATA EXTRACTION

Two independent reviewers performed the data search, quality assessment, and data extraction. We included both prospective and retrospective studies; risk of bias was evaluated using the ROBINS-I tool. The primary outcome was the proportion of adequate samples obtained by EBUS-TBNA for molecular analysis. Data were pooled by using a binary random effects model. Finally, evidence was rated by using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach.

RESULTS

A total of 33 studies including 2,698 participants were analyzed. In 28 studies that evaluated EBUS-TBNA for the identification of EGFR mutations, the pooled probability of obtaining a sufficient sample was 94.5% (95% confidence interval CI], 93.2-96.4%). For identification of ALK mutations, the pooled probability was 94.9% (95% CI, 89.4-98.8%). Finally, the prevalence of EGFR mutation was 15.8% (95% CI, 12.1-19.4%), and the prevalence of ALK mutation was 2.77% (95% CI, 1.0-4.8%). Data for ROS1 and PD-L1 mutations were not suitable for meta-analysis.

CONCLUSIONS

EBUS-TBNA has a high yield for molecular analysis of both EGFR and ALK mutations. However, the suitability of TBNA samples for next-generation sequencing is uncertain and should be explored in further studies. Clinical trial registered with PROSPERO (CRD42017080008).

Diagnostic Performance of Radial Probe Endobronchial Ultrasound without a Guide-Sheath and the Feasibility of Molecular Analysis

BACKGROUND

Radial probe endobronchial ultrasound (R-EBUS), is effective for tissue diagnosis of lung lesions. We evaluated the diagnostic performance of R-EBUS both a guide-sheath and fluoroscopy and identified factors associated with accurate diagnosis. The feasibility of molecular and genetic testing, using specimens obtained by R-EBUS, was also investigated.

METHODS

The study retrospectively reviewed 211 patients undergoing R-EBUS without a guide-sheath and fluoroscopy, June 2016-May 2017. After excluding 27 patients of which the target lesion was not reached, 184 were finally included. Multivariate logistic regression was used, to identify factors associated with accurate diagnosis.

RESULTS

Among 184 patients, R-EBUS-guided biopsy diagnosed malignancy in 109 patients (59%). The remaining 75 patients (41%) with non-malignant results underwent additional work-ups, and 34 were diagnosed with malignancy. Based on final diagnosis, diagnostic accuracy was 80% (136/170), and sensitivity and specificity for malignancy were 76% (109/143) and 100% (27/27), respectively. In multivariate analysis, peripheral location (adjusted odds ratio [aOR], 3.925; 95% confidence interval [CI], 1.203-12.811; p=0.023), and central position of the probe (aOR, 2.435; 95% CI, 1.424-7.013; p=0.035), were associated with accurate diagnosis of malignancy. Molecular and genetic analyses were successful, in all but one case, with inadequate specimens.

CONCLUSION

R-EBUS-guided biopsy without equipment, is effective for tissue diagnosis. Peripheral location and central position of the radial probe, were crucial for accurate diagnosis. Performance of molecular and genetic testing, using samples obtained by R-EBUS, was satisfactory.

Afatinib is effective in the treatment of lung adenocarcinoma with uncommon EGFR p.L747P and p.L747S mutations

OBJECTIVES

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are used as first-line standard treatment for advanced lung adenocarcinoma with mutant EGFR. Nevertheless, few studies have demonstrated the efficacy of first- and second-generation EGFR TKIs in patients harboring the uncommon p.L747P and p.L747S mutations in exon 19 of EGFR.

MATERIALS AND METHODS

From 2005-2018, we identified patients with lung adenocarcinoma with EGFR p.L747P or p.L747S mutations using DNA and cDNA sequencing or commercial kits and recorded their clinical data. Published data pertaining to these mutations were also reviewed.

RESULTS

Twelve eligible patients were enrolled at National Taiwan University Hospital (NTUH), and ten additional patients were identified in published literature. In NTUH cohort, the direct DNA sequencing had a 60.0% (3 of 5 patients) false-negative rate, and use of commercial kits all caused misidentification of EGFR p.L747P or p.L747S. Of the 7 patients receiving EGFR TKI treatment, five stage-IV lung adenocarcinoma patients that received afatinib had a 80.0% objective response rate (ORR), while two patients administered gefitinib or erlotinib showed a 0% ORR. The median progression-free survival (PFS) rates were 11.97 and 0.92 months (P = 0.012) for afatinib and gefitinib/erlotinib, respectively. No patients (0%) acquired p.T790 M resistance after failure of afatinib (n = 3). Of 10 patients harboring EGFR p.L747P from published literature, six patients used first-generation EGFR TKIs as treatment also showed 0% ORR and 1.00 month median PFS.

CONCLUSIONS

Patients with the uncommon EGFR mutations p.L747P and p.L747S could be incorrectly classified as having wild-type EGFR or a 19DEL when using direct DNA sequencing or commercial kits. Moreover, use of afatinib may provide significantly improved PFS in patients with advanced lung adenocarcinoma with one of these two EGFR mutations.

Molecular analysis of peripheral lung adenocarcinoma in brush cytology obtained by EBUS plus fluoroscopy-guided bronchoscopy

BACKGROUND

More than 60% of patients with lung cancer are diagnosed at advanced stages. The introduction of targeted therapies requires molecular diagnosis to guide treatment. The aim of this study was to evaluate the feasibility of performing mutational analysis with brushing specimens obtained by radial-miniprobe endobronchial ultrasound (R-EBUS) plus fluoroscopy-guided bronchoscopy in patients with peripheral pulmonary adenocarcinoma.

METHODS

Brushing specimens were deposited on cytological slides and were conserved in Roswell Park Memorial Institute (RPMI) culture medium. DNA was isolated to perform a mutational analysis with real-time quantitative polymerase chain reaction and Sanger sequencing for epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene homolog (KRAS).

RESULTS

Thirty patients with adenocarcinoma were prospectively included. In 100% of the patients, the molecular study was viable with brushing specimens. In 16 (53.3%), KRAS or EGFR mutations were detected: 10 KRAS mutations (33.3%) and 6 EGFR mutations (20%). In a comparison with histological samples, a correlation of 86.6% was detected, and only 2 patients with wild-type results from brushing specimens presented with an EGFR mutation in histological samples.

CONCLUSIONS

Brushing specimens conserved in RPMI medium and obtained by R-EBUS plus fluoroscopy-guided bronchoscopy are valid for molecular studies. They allow the detection of EGFR/KRAS mutations in patients with peripheral adenocarcinoma. In addition, invasive techniques are avoided, the risk of complications is reduced, and the obtained samples are optimized.

The value of radial endobronchial ultrasound-guided bronchial brushing in peripheral non-squamous non-small cell lung cancer

Radial endobronchial ultrasound (R-EBUS) is one important diagnostic approach in non-small cell lung cancers (NSCLC). However, the small samples obtained from R-EBUS-guided transbronchial biopsies are sometimes insufficient for pathological and molecular diagnosis. Herein, we investigated the suitability of R-EBUS-guided bronchial brushing specimens for NSCLC diagnosis and EGFR genotyping. We enrolled 941 consecutive patients with peripheral pulmonary lesions who underwent R-EBUS. Cytology-positive brushing specimens from non-squamous NSCLC patients were tested for EGFR mutations. Non-squamous NSCLC was diagnosed in 624 patients (66.3%). Positive cytology was documented in the brushing samples of 376 patients (60.3%). Higher diagnostic yields were obtained in patients exhibiting bronchus signs on chest tomography, and those with R-EBUS probe located within the lesion. EGFR genotyping was successfully performed in 363 samples (96.5% of cytology-positive brushing samples). EGFR genotyping concordance between brushing specimens and matched tissue samples was 88.7% (kappa = 0.745, P < 0.001). Furthermore, 144 non-squamous NSCLC patients (23.1%) with failed pathological diagnosis or EGER sequencing by R-EBUS-guided transbronchial biopsy required repeat biopsies. However, it was achieved successfully from the brushing specimens of 57 patients (39.6%). In conclusion, for patients with peripheral lung cancer, R-EBUS-guided bronchial brushing could provide an additional sampling method for diagnosis and EGFR genotyping.

The mechanism of acquired resistance to irreversible EGFR tyrosine kinase inhibitor-afatinib in lung adenocarcinoma patients

Introduction

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are associated with favorable response in EGFR mutant lung cancer. Acquired resistance to reversible EGFR TKIs remains a significant barrier, and acquired EGFR T790M-mutation is the major mechanism. Second-generation irreversible EGFR TKI, afatinib, had also been approved for treating EGFR mutant lung cancer patients, but the mechanism of acquired resistance to afatinib has not been well studied.

Results

Forty-two patients had tissue specimens taken after acquiring resistance to afatinib. The sensitizing EGFR mutation were all consistent between pre- and post-afatinib tissues. Twenty patients (47.6%) had acquired T790M mutation. T790M rate was not different between first-generation EGFR TKI-naïve patients (50%) and first-generation EGFR TKI-treated patients (46.4%) (p = 0.827). No clinical characteristics or EGFR mutation types were associated with the development of acquired T790M. No other second-site EGFR mutations were detected. There were no small cell or squamous cell lung cancer transformation. Other genetic mutations were not identified in PIK3CA, BRAF, HER2, KRAS, NRAS, MEK1, AKT2, LKB1 and JAK2.

Methods

Afatinib-prescription record of our department of pharmacy from January 2007 and December 2014 was retrieved. We investigated patients with tissue specimens available after acquiring resistance to afatinib. Enrolled patients should have partial response or durable stable disease of treatment response to afatinib. Various mechanisms of acquired resistance to first-generation EGFR TKIs were evaluated. Histology and cytology were reviewed. EGFR, PIK3CA, BRAF, HER2, KRAS, NRAS, MEK1, AKT2, LKB1 and JAK2 genetic alterations were evaluated by sequencing. Statistical analysis was performed using Chi-square test and Kaplan-Meier method.

Conclusions

T790M was detected in half of the lung adenocarcinoma after acquiring resistance to afatinib. T790M is still the major acquired resistance mechanism. First-generation EGFR TKI exposure did not influence the prevalence of T790M in lung cancer acquired resistance to afatinib.

Lung adenocarcinoma patients of young age have lower EGFR mutation rate and poorer efficacy of EGFR tyrosine kinase inhibitors

Patients aged ≤50 years are rarely diagnosed with nonsmall cell lung cancer. We conducted a retrospective cohort study to understand the mutation status of EGFR and the efficacy of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment in young Asian patients with lung adenocarcinoma.

We collected tumour specimens and malignant pleural effusions from lung adenocarcinoma patients from June 2005 to April 2014, recorded their clinical demographic data, and analysed EGFR mutations by reverse transcriptase PCR.

EGFR mutation data were collected from 1039 lung adenocarcinoma patients, including 161 patients aged ≤50 years and 878 patients aged >50 years. Fewer patients aged ≤50 years had EGFR mutations than older patients (p=0.043), but they showed a higher rate of uncommon EGFR mutations (p=0.035). A total of 524 patients with EGFR mutations received EGFR-TKI treatment, including 81 patients aged ≤50 years. Younger patients had a lower response rate than older patients (p=0.038) and had the shortest progression-free survival compared with other predefined age categories (p=0.033). Multivariate analysis of overall survival revealed age ≤50 years as a poor prognostic factor.

In conclusion, fewer Asian patients aged ≤50 years had EGFR mutations, but the EGFR mutation types were more uncommon. Age ≤50 years is associated with poorer efficacy of EGFR-TKI treatment.

Association between age and EGFR mutationshttp://ow.ly/jV4n30bRBUX

Outcomes of research biopsies in clinical trials of EGFR mutation-positive non-small cell lung cancer patients pretreated with EGFR-tyrosine kinase inhibitors

BACKGROUND/PURPOSE

Research biopsies (RBs) are crucial for developing novel molecular targeted agents. However, the safety and diagnostic yields of RBs have not been investigated in EGFR mutation-positive non-small cell lung cancer (NSCLC) patients pretreated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs).

METHODS

We searched the medical records of NSCLC patients who participated in lung cancer clinical trials and underwent mandatory RBs between 2012 and 2014 at our institution. Only patients with EGFR mutation-positive NSCLC pretreated with at least 1 EGFR-TKI were enrolled.

RESULTS

Of 140 enrolled patients, 73 (52.1%) and 59 (42.1%) had exon 19 deletions and exon 21 L858R mutation, respectively. Before RBs, 108 (77.1%), 83 (59.3%), and 36 (25.7%) patients had been treated with gefitinib, erlotinib, and afatinib, respectively. Computed tomography-guided percutaneous core needle biopsy was the most frequently used modality among 181 RBs performed (50.8%), followed by ultrasonography-guided (32.0%) and endoscopic RBs (16.0%). The most common RB sites were the lung (69.6%), pleura (8.8%), and liver (6.1%). Pathologic examinations revealed malignant cells in most RB specimens (72.9%). Complications due to RBs included pneumothorax (11.6%), bleeding (6.1%), and infection (1.1%). Only 1 patient required chest tube placement for pneumothorax, and 2 patients underwent endotracheal intubation because of bleeding.

CONCLUSION

RBs in this patient population were generally safe. Pneumothorax was the most frequent complication; bleeding, while infrequent, increased the risk of severe events. The diagnostic yields and complications of any particular modality should therefore be discussed with prospective clinical trial participants.

Molecular biomarkers for lung adenocarcinoma

The identification of oncogenic driver alterations that underlie sensitivity to small inhibitors has led to growing interest in identifying additional targetable oncogenes in nonsmall cell lung cancer. Although the therapeutic impact of the discovery of these alterations has now been widely demonstrated, the epidemiological data associated with each of these biomarkers remain insufficiently studied. In this review, we discuss the techniques used to discover each of these candidate oncogenes, their prevalence in nonsmall cell lung cancer, and briefly outline the epidemiological features of the major oncogenes and ways in which their identification can determine therapeutic strategies.

Comparable clinical outcomes in patients with HER2-mutant and EGFR-mutant lung adenocarcinomas

HER2 is a major proliferative driver in lung cancer. HER2 gene aberrations impact the prognosis of lung adenocarcinoma (ADC). A one-step reverse transcription-polymerase chain reaction was performed using RNA samples from 888 Asian lung cancer patients to detect HER2, EGFR, KRAS, ALK, and ROS1 mutations. The demographic data and treatment outcomes of HER2 mutation-positive lung ADC patients were analyzed and compared to those with HER2 mutation-negative tumors. HER2 mutation was identified in 40 (4.5%) lung ADC patients. HER2 mutations tended to occur in male patients with advanced-stage disease and never-smokers. A775_G776insYVMA (n = 22, 55%) was the most prevalent HER2 mutation, followed by P780_Y781insGSP (n = 4, 10%). For patients diagnosed with stage-IIIB/IV disease, HER2-mutant patients showed clinical outcomes comparable to EGFR-mutant patients (P = 0.721, log-rank test) and a better overall survival (OS) compared to patients lacking driver mutations in the investigated genes (P = 0.033, Breslow test). Specifically, lung ADC patients with stage-IV HER2-mutant tumors treated with chemotherapy or targeted agents, even without afatinib or anti-HER2 targeted therapy, showed similar clinical outcomes to lung ADC patients harboring EGFR exon 19 deletion or L858R mutations (P = 0.870). In addition, multivariate analysis indicated that HER2 mutation status was not a major risk factor for diminished OS in stage-IV lung cancer. In conclusion, lung ADC harboring HER2 mutations showed distinct characteristics from other driver mutations, including increased chemosensitivity with in advanced stage disease.

Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor-sensitive Exon 19 Insertion and Exon 20 Insertion in Patients With Advanced Non-Small-cell Lung Cancer

BACKGROUND

The clinical responsiveness to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in non-small-cell lung cancer (NSCLC) patients with exon 19 insertion and the specific exon 20 insertion (A763_Y764 insFQEA) are still not well known.

MATERIALS AND METHODS

We analyzed cancer specimens taken from NSCLC patients for EGFR mutations using RNA reverse transcription polymerase chain reaction or direct DNA sequencing. The clinical course and responsiveness to an EGFR TKI in patients with EGFR exon 19 insertion or exon 20 insertion (A763_Y764 insFQEA) were recorded. The published data regarding these mutations were also reviewed.

RESULTS

From September 1995 to May 2015, we found 4 patients with an EGFR exon 19 insertion and 6 patients with an EGFR exon 20 insertion (A763_Y764 insFQEA) at the National Taiwan University Hospital. Among patients with an exon 19 insertion, 3 received an EGFR TKI. Of the 3 patients, 1 had a partial response, 1 had stable disease, and 1 had progressive disease. Of the 6 patients with the exon 20 insertion (A763_Y764 insFQEA), 3 received an EGFR TKI. Of those 3 patients, 2 had a partial response and 1 had progressive disease. A review of the published data, together with the data from our patients, patients with an exon 19 insertion and treated with an EGFR TKI (n = 18) had a response rate of 56% and a median time to progression of 10.4 months. Patients with the exon 20 insertion (A763_Y764 insFQEA) and treated with an EGFR TKI (n = 11) had a response rate of 73% and a median time to progression of 5.0 months.

CONCLUSIONS

Advanced NSCLC bearing the EGFR exon 19 insertion or exon 20 insertion (A763_Y764 insFQEA) is sensitive to EGFR TKIs.

A comprehensive analysis of clinical outcomes in lung cancer patients harboring a MET exon 14 skipping mutation compared to other driver mutations in an East Asian population

INTRODUCTION

Recurrent somatic splice-site alterations at MET exon 14 (MET^Δ14), which result in exon skipping and MET proto-oncogene, receptor tyrosine kinase (MET) activation, have been characterised. However, their demographic features and clinical outcomes in East Asian lung cancer patients have yet to be determined.

METHODS

A one-step reverse transcription-polymerase chain reaction (RT-PCR), using RNA samples from 850 East Asian lung cancer patients, was performed in order to detect MET^Δ14 and five other major driver mutations, including those in the EGFR, KRAS, ALK, HER2, and ROS1 genes. Immunohistochemistry (IHC) was used to confirm the overexpression of MET in patients harbouring the MET^Δ14 mutation. We analysed the demographic data and clinical outcomes of MET^Δ14 mutation positive lung cancer patients and compared them to those of MET^Δ14 mutation negative lung cancer patients.

RESULTS

In total, 27 lung adenocarcinoma (ADC) patients and 1 squamous cell carcinoma patient with the MET^Δ14 mutation were identified. The overall incidence was 3.3% for lung cancer and 4.0% for lung ADC. IHC demonstrated that the majority of lung cancer patients harboring a MET^Δ14 mutation exhibited a strong cytoplasmic expression of MET. MET^Δ14 mutation positive patients were generally quite elderly individuals. Stage IV MET^Δ14 mutation positive lung cancer patients receiving no specific anti-MET therapy were observed to have a similar overall survival (OS) compared to patients in the all negative group (P>0.05). In the multivariate analysis, mutation status was found not to be a major risk factor for OS in lung cancer patients without appropriate tyrosine kinase inhibitors treatment.

CONCLUSIONS

The OS of MET^Δ14 mutation positive lung cancer patients is comparable to that of the major driver gene mutation negative lung cancer patients.

The feasibility of molecular testing on cell blocks created from brush tip washings in the assessment of peripheral lung lesions

BACKGROUND

With the rapid development of genotype-guided therapies, molecular testing is becoming important in the management of lung cancer. Bronchoscopy is one of the most common investigations performed to diagnose and investigate lung cancer. Given the limited samples often produced by bronchoscopy, this study aims to evaluate the feasibility of performing molecular testing on cell blocks created from bronchoscope cytology brush tip washings (BTW).

METHODS

Patients with positive brush cytology for tumour cells had cell blocks created from the BTW. Mutations were detected using amplicon-based massively parallel sequencing of targeted regions of EGFR, KRAS, and BRAF genes.

RESULTS

A total of 45 patients were included in this study. Of those, 91% had adequate specimens for molecular analysis and 66% of patients with adenocarcinoma had mutations detected. Bronchial brush tip wash cell blocks were the sole specimen available for molecular testing in 27 (60%) patients.

CONCLUSIONS

The findings of this study demonstrate that molecular testing can be performed on cell blocks created from BTW and this technique may allow for an increase in bronchoscope specimens amenable to molecular testing without further increasing morbidity and mortality.

In Vitro Drug Sensitivity Tests to Predict Molecular Target Drug Responses in Surgically Resected Lung Cancer

BACKGROUND

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and anaplastic lymphoma kinase (ALK) inhibitors have dramatically changed the strategy of medical treatment of lung cancer. Patients should be screened for the presence of the EGFR mutation or echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion gene prior to chemotherapy to predict their clinical response. The succinate dehydrogenase inhibition (SDI) test and collagen gel droplet embedded culture drug sensitivity test (CD-DST) are established in vitro drug sensitivity tests, which may predict the sensitivity of patients to cytotoxic anticancer drugs. We applied in vitro drug sensitivity tests for cyclopedic prediction of clinical responses to different molecular targeting drugs.

METHODS

The growth inhibitory effects of erlotinib and crizotinib were confirmed for lung cancer cell lines using SDI and CD-DST. The sensitivity of 35 cases of surgically resected lung cancer to erlotinib was examined using SDI or CD-DST, and compared with EGFR mutation status.

RESULTS

HCC827 (Exon19: E746-A750 del) and H3122 (EML4-ALK) cells were inhibited by lower concentrations of erlotinib and crizotinib, respectively than A549, H460, and H1975 (L858R+T790M) cells were. The viability of the surgically resected lung cancer was 60.0 ± 9.8 and 86.8 ± 13.9% in EGFR-mutants vs. wild types in the SDI (p = 0.0003). The cell viability was 33.5 ± 21.2 and 79.0 ± 18.6% in EGFR mutants vs. wild-type cases (p = 0.026) in CD-DST.

CONCLUSIONS

In vitro drug sensitivity evaluated by either SDI or CD-DST correlated with EGFR gene status. Therefore, SDI and CD-DST may be useful predictors of potential clinical responses to the molecular anticancer drugs, cyclopedically.

Anaplastic Lymphoma Kinase (ALK) Kinase Domain Mutation Following ALK Inhibitor(s) Failure in Advanced ALK Positive Non-Small-Cell Lung Cancer: Analysis and Literature Review

BACKGROUND

Secondary anaplastic lymphoma kinase (ALK) mutation may occur in patients with advanced ALK-positive non-small cell lung cancer treated with ALK inhibitors, but its nature is not well-known.

PATIENTS AND METHODS

We analyzed tumor specimens after the failure of treatment with ALK inhibitor(s) (crizotinib, alectinib, and ceritinib) for secondary ALK kinase domain mutation, EGFR, K-ras, and PIK3CA mutations. The literature regarding acquired ALK-inhibitor(s) resistance was also reviewed.

RESULTS

Among 59 patients who received ALK inhibitor(s) during the period of December 2010 to April 2015, 7 had re-biopsied tumor specimens for analyses following ALK inhibitor(s) failure. One had G1202R after crizotinib and alectinib failure, and 6 were wild type. No EGFR, K-ras, or PIK3CA mutations were found. In our review of the literature and taken together with our patients, 25 of the 88 (28%) patients with crizotinib failure had secondary ALK mutation; L1196M mutation was most common (n = 11). Patients with secondary ALK mutation other than L1196M had a longer progression-free survival after crizotinib than patients with L1196M (median, 12.0 vs. 7.0 months; P = .04). Of the 9 patients with alectinib failure, 5 had I1171 mutation and 2 had G1202R. Of the 11 patients with ceritinib failure, 2 had G1202R, 1 had F1174C, and 1 had both G1202R and F1174V. I1171 mutation, G1202R, and F1174 mutations were also found in crizotinib-failed patients.

CONCLUSIONS

Some acquired ALK mutations may cause co-resistance to other ALK inhibitors. Re-biopsy for ALK mutation analysis might be suggested prior to choosing a second-line ALK inhibitor treatment.

Diagnostic Utility of Bronchial Brush-Tip Washings for the Immunohistochemical Assessment of Peripheral Lung Lesions

OBJECTIVES

Immunohistochemistry (IHC) is an important component of lung cancer diagnosis and management, although performance can be limited due to tissue availability. We describe a novel technique for processing brush-tip washings (BTW) and evaluate the feasibility of IHC testing on these samples.

STUDY DESIGN

All patients who had cell blocks (CB) created from BTW following bronchoscopic investigation of peripheral lung lesions were included. CB were assessed for adequate material before undergoing IHC staining.

RESULTS

75 patients were included in the study, with bronchoscopic diagnosis of malignancy achieved in 77%. Sixty-seven samples (89%) had sufficient cells for diagnosis on CB and 56 of these (84%) proved amenable to IHC. CB created from BTW were the sole specimens available for IHC subtyping in 7 patients (9%).

CONCLUSIONS

CB are easily created from BTW and are a simple method for increasing the diagnostic utility of bronchoscopic specimens without increasing the risk or duration of bronchoscopy. IHC can be easily performed in a high proportion of cases, increasing the likelihood of accurate sub-typing of tumours following diagnostic bronchoscopy.

Radial Endobronchial Ultrasound (EBUS) Guided Suction Catheter-Biopsy in Histological Diagnosis of Peripheral Pulmonary Lesions

BACKGROUND

EBUS guided trans-bronchial biopsy became routine in diagnosis of peripheral pulmonary lesions (PPL). Suction catheter-biopsy is a technique for obtaining a tissue sample from peripheral lung parenchyma. Aim of this study was to evaluate diagnostic efficiency, feasibility and safety of EBUS guided suction catheter-biopsy (SCB) in comparison to trans-bronchial biopsy (TBB) in diagnosis of PPL. The main intention was to demonstrate non-inferiority of the technique over trans-bronchial biopsy, especially when used under navigation of the EBUS.

METHODS

Radial EBUS probe (UM-3R, Olympus Co, Japan.) without guiding sheath was used to navigate suction catheter and TBB forceps to the PPL. The catheter was connected to the collection canister via vacuum pump. The SCB specimens were fixed with 10% buffered formalin.

RESULTS

There were 168 patients enrolled in this study; 69.9% males and 30.1% females. Main lesion diameter was 4.1±1.9 cm. Majority of patients, 131(77.9%) were diagnosed with lung cancer. Per-biopsy calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for EBUS-SCB were 92.4%, 100%, 100% and 67.7%, respectively. Corresponding values for EBUS-TBB were 92.3%, 100%, 100% and 69.7%. Only the size of the lesion significantly influenced (p=0.005) diagnostic performance. Complications occurred in 2 patients; one pneumothorax and one excessive bleeding.

CONCLUSION

EBUS guided SCB is efficient, feasible and safe in diagnosis of peripheral lung cancer. The technique is complementary to trans-bronchial biopsy.

Clinical and the prognostic characteristics of lung adenocarcinoma patients with ROS1 fusion in comparison with other driver mutations in East Asian populations

INTRODUCTION

The prevalence, demographic features, and clinical outcomes of lung adenocarcinoma patients with novel ROS1 oncogenic rearrangement in East Asian populations are not clear. This study aimed to investigate the clinical and prognostic characteristics of lung adenocarcinoma in patients with ROS1 fusion compared with other driver mutations.

METHODS

Multiplex reverse transcription-polymerase chain reaction was used to detect the ROS1 fusion gene in lung adenocarcinoma cases. Immunohistochemistry was used to confirm the expression of ROS1. The demographic data and clinical outcomes of patients with the ROS1 fusion gene were compared with those of patients without the ROS1 fusion gene, including those with the EGFR mutation, EML4-ALK fusion, KRAS mutation, and quadruple-negative patients.

RESULTS

Of 492 patients with lung adenocarcinoma, 12 (2.4%) had the ROS1 fusion gene. Their median age was 45.0 years, significantly younger than that of the ROS1 fusion-negative cohorts (p < 0.001). Acinar (including cribriform) and solid patterns were the two most common histologic subtypes in the ROS1 fusion tumors (7 of 12, 58.3%) and were predominantly seen in CD74-ROS1 fusion tumors (66.7%). There was no significant survival difference between the ROS1 fusion-positive and ROS1 fusion-negative cohorts in surgical group, but ROS1 fusion-positive patients might have worse outcomes than EGFR-mutant patients in the stage IV group.

CONCLUSIONS

The ROS1 fusion gene can be successfully detected in East Asian patients with lung adenocarcinoma using multiplex reverse transcription-polymerase chain reaction. These patients tend to be younger and have characteristic histologic subtypes. Due to the small number of ROS1 fusion patients, the prognostic value of ROS1 fusion need further studies to confirm.

A novel point-of-care system for high-speed real-time polymerase chain reaction testing for epidermal growth factor receptor mutations in bronchial lavage fluids after transbronchial biopsy in patients with non-small cell lung cancer

Epidermal growth factor receptor (EGFR) gene mutation testing is essential for choosing appropriate treatment options in patients with advanced non-small cell lung cancer (NSCLC). However, a time delay occurs between histological diagnosis and molecular diagnosis in clinical situations. To minimize this delay, we developed a novel point-of-care test for EGFR mutations, based on a high-speed real-time polymerase chain reaction (PCR) system designated here as ultrarapid PCR combined with highly accurate bronchoscopic sampling. We investigated whether our system for detecting EGFR mutations was valid by comparing test results with those obtained using a commercialized EGFR mutation test. We obtained small amounts of bronchial lavage fluids after transbronchial biopsies (TBBs) were performed on enrolled patients (n=168) who underwent endobronchial ultrasonography using a guide sheath (EBUS-GS). EGFR mutation analysis was performed by ultrarapid PCR immediately after EBUS-GS-TBBs were obtained (on the same day). After pathological diagnoses of NSCLC, EGFR mutation status in formalin-fixed, paraffin- embedded samples was confirmed by the PCR-invader method, and the concordance rates between the PCR methods were compared. The total diagnostic yield of EBUS-GS-TBB was 91.0%. The positive concordance rates for detecting 19del and L858R with the ultrarapid PCR and PCR-invader methods were both 100%. Negative concordance rates were 97.2 and 98.1%, respectively. We also demonstrated a dramatic effect of early erlotinib administration, based on ultrarapid PCR results, for a 52-year-old woman suffering from respiratory failure due to severe intrapulmonary metastases with poor performance status. In conclusion, ultrarapid PCR combined with EBUS-GS-TBB enabled rapid and reliable point-of-care testing for EGFR mutations.

The diagnostic value of histology and cytology samples during endobronchial ultrasound with a guide sheath

OBJECTIVE

Endobronchial ultrasound with a guide sheath has been a widely used diagnostic procedure for peripheral pulmonary lesions. After sequential sampling with the usual devices, small portions of the collected specimen remain in the guide sheath and these can potentially contribute to diagnosis. We assessed the diagnostic value of each histological and cytological sample, especially the guide sheath flush, for pulmonary malignancies.

METHODS

The medical records of patients who were diagnosed to have peripheral lung cancer by endobronchial ultrasound with a guide sheath in our hospital between January 2014 and May 2014 were reviewed. Separate samples from forceps biopsy, bronchial brushing, device wash, guide sheath flush and bronchial lavage were compared and analyzed.

RESULTS

A total of 106 consecutive patients (54 men, 52 women, median age 69.0 years) were included. The median long axis size of the lesions was 26.0 mm. A definitive diagnosis was made in 90.6% of forceps biopsy samples and in 85.8% of all cytology samples combined. Individual yields were 61.3% from brushing, 77.4% from device wash, 72.6% from guide sheath flush and 32.1% from bronchial lavage. The diagnosis yield from forceps biopsy was significantly higher than each cytological sampling method (P < 0.05). Among the cytological sampling methods, yield from bronchial lavage was significantly the lowest (P < 0.001).

CONCLUSIONS

Forceps biopsy is an important sampling method during endobronchial ultrasound with a guide sheath for peripheral pulmonary lesions. In the collection of diagnostic liquid samples, guide sheath flush is more advantageous than bronchial lavage and provides specimen that may be adequate for molecular testing.

Diagnostic utility and accuracy of rapid on-site evaluation of bronchoscopic brushings

The aim of the study was to determine the accuracy of rapid on-site examinations, performed on transbronchial brushings of peripheral pulmonary lesions, in determining final bronchoscopic diagnosis. In addition to determining if rapid on-site examination impacts procedural outcomes. A prospective cohort study of consecutive patients with peripheral pulmonary lesions, which had been located by radial endobronchial ultrasound, was undertaken. Bronchoscopy was terminated if rapid on-site examination demonstrated diagnostic malignant material. Non-diagnostic rapid on-site examination resulted in further bronchoscopic sampling, including transbronchial lung biopsy and/or sampling from different locations. 128 peripheral pulmonary lesions were located by endobronchial ultrasound in 118 patients. The final bronchoscopic diagnoses included nonsmall cell lung cancer (n=76), carcinoid (n=3), and metastatic malignancy (n=3). Procedure times were significantly shorter for procedures when rapid on-site examinations demonstrated malignancy compared to those where rapid on-site examination was non-diagnostic (19±8 min versus 31±11 min, respectively; p<0.0001). In four procedures, initial negative rapid on-site examination results prompted redirection of sampling from alternate bronchial segments, resulting in positive diagnostic tissue being obtained. Positive and negative predictive value of rapid on-site examination for a malignant bronchoscopic diagnosis was 63 (97%) out of 65, and 43 (68%) out of 63, respectively. Rapid on-site examination of brushing specimens has a very high, positive, predictive value for bronchoscopic diagnosis of cancer and shortens the bronchoscopy procedure times. It has the potential to reduce complications, improve cost-effectiveness, and may improve diagnostic performance via live feedback.

Strategic management of transthoracic needle aspirates for histological subtyping and EGFR testing in patients with peripheral lung cancer: An institutional experience

BACKGROUND

Lung cancer therapy is personalized based on the histological subtype and molecular status. Totally, 70% of lung cancer patients present in advanced stages and are diagnosed on small biopsy or cytology specimens, hence an accurate but tissue-sparing approach is necessary. This study aimed to demonstrate efficient utilization of cell block (CB) on transthoracic needle aspiration (TTNA) for lung cancer subtyping, and to investigate the usefulness of needle washing after TTNA for assessing EGFR molecular status.

METHODS

Each TTNA specimen from the 79 peripheral lung masses was divided into three parts; liquid-based cytology (LBC), CB (with or without immunohistochemistry), and needle washing for analysis of EGFR mutation using peptide nucleic acid-mediated real-time PCR clamping.

RESULTS

Totally 79 specimens were diagnosed as malignancy, 75 (94.9%), benign, 3 (3.8%), and inadequate specimen, 1 (1.3%). The combination of LBC and CB (92.0%) showed a higher diagnostic yield for definitive subtyping of lung cancer than LBC alone (72.0%). Of the 75 malignant cases, 17 (22.7%) showed an EGFR mutation in needle washing specimens. EGFR mutational status was compared in all paired needle washing and scraped CBs with a 100% concordance.

CONCLUSIONS

We hereby proposed a strategy to maximize biological information retrieval from a limited TTNA specimen in patients with peripheral lung cancer. This algorithm indicated CB preparation for accurate histological subtyping and waste needle washing for molecular testing.

Optimizing tissue sampling for the diagnosis, subtyping, and molecular analysis of lung cancer

Lung cancer has entered the era of personalized therapy with histologic subclassification and the presence of molecular biomarkers becoming increasingly important in therapeutic algorithms. At the same time, biopsy specimens are becoming increasingly smaller as diagnostic algorithms seek to establish diagnosis and stage with the least invasive techniques. Here, we review techniques used in the diagnosis of lung cancer including bronchoscopy, ultrasound-guided bronchoscopy, transthoracic needle biopsy, and thoracoscopy. In addition to discussing indications and complications, we focus our discussion on diagnostic yields and the feasibility of testing for molecular biomarkers such as epidermal growth factor receptor and anaplastic lymphoma kinase, emphasizing the importance of a sufficient tumor biopsy.

Multidriver mutation analysis in pulmonary mucinous adenocarcinoma in Taiwan: identification of a rare CD74-NRG1 translocation case

Several new chromosomal translocations resulting in driver fusion mutations have recently been discovered in non-small-cell lung cancer. The driver mutational patterns in pulmonary mucinous adenocarcinoma, a rare subtype of non-small-cell lung cancer, have not been well studied. A single-institute cohort study in Taiwan was performed to determine the mutations of epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS), fusions of anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1), and neuregulin 1 (NRG1) in patients diagnosed with pulmonary mucinous adenocarcinoma. We also examined NRG1 translocation in patients diagnosed as adenocarcinoma of other subtypes with wild-type EGFR, KRAS, ALK, and ROS1 genes. Surgical or biopsy specimens were collected from 13 patients with mucinous adenocarcinoma. Using the direct RNA sequencing method, we discovered a rare CD74-NRG1 fusion (8 %), an echinoderm microtubule-associated protein like 4 (EML4)-ALK fusion (17 %), and three KRAS mutations (25 %). No EGFR mutations or ROS1 rearrangements were detected. The rare CD74-NRG1 fusion positive patient presented with uncommon radiological features. We did not detect any CD74-NRG1 fusion in the 109 adenocarcinoma of other subtypes, which were all negative for EGFR, KRAS, ALK, and ROS1. The CD74-NRG1 fusion mutation is rare and may be exclusively present in patients with pulmonary mucinous adenocarcinoma. Patients harboring CD74-NRG1 positive tumors may present with uncommon imaging features.