Detection and comparison of EGFR mutations in matched tumor tissues, cell blocks, pleural effusions, and sera from patients with NSCLC with malignant pleural effusion, by PNA clamping and direct sequencing

K-ras mutation detected by peptide nucleic acid-clamping polymerase chain reaction, Ki-67, S100P, and SMAD4 expression can improve the diagnostic accuracy of inconclusive pancreatic EUS-FNB specimens

OBJECTIVES

We aimed to assess the diagnostic utility of an immunohistochemical panel including calcium-binding protein P, p53, Ki-67, and SMAD family member 4 and K-ras mutation for diagnosing pancreatic solid lesion specimens obtained by endoscopic ultrasound-guided fine-needle biopsy and to confirm their usefulness in histologically inconclusive cases.

METHODS

Immunohistochemistry and peptide nucleic acid-clamping polymerase chain reaction for K-ras mutation were performed on 96 endoscopic ultrasound-guided fine-needle biopsy specimens. The diagnostic efficacy of each marker and the combination of markers was calculated. The diagnostic performances of these markers were evaluated in 27 endoscopic ultrasound-guided fine-needle biopsy specimens with histologically inconclusive diagnoses. A classification tree was constructed.

RESULTS

K-ras mutation showed the highest accuracy and consistency. Positivity in more than two or three of the five markers showed high diagnostic accuracy (94.6 % and 93.6 %, respectively), and positivity for more than three markers showed the highest accuracy for inconclusive cases (92.0 %). A classification tree using K-ras mutation, Ki-67, S100P, and SMAD4 showed high diagnostic performance, with only two misclassifications in inconclusive cases.

CONCLUSIONS

K-ras mutation detection via peptide nucleic acid-clamping polymerase chain reaction is a stable and accurate method for distinguishing between pancreatic ductal adenocarcinoma and non-pancreatic ductal adenocarcinoma lesions. A classification tree using K-ras mutation, Ki-67, S100P, and SMAD4 helps increase the diagnostic accuracy of cases that are histologically difficult to diagnose.

Adequacy of pleural fluid cytology for comprehensive molecular analysis of lung adenocarcinoma: Experience of a large health-care system

Objectives:

Pleural fluid evaluation is an effective modality for identifying actionable genetic mutations to guide therapy in lung carcinoma. Clinicians requesting molecular studies often send large volumes of fluid to be processed that is not possible or cost effective and is hence not standard of practice in most cytopathology laboratories. We wanted to establish the characteristics of an adequate specimen that would yield reliable results with current molecular testing platforms.

Material and Methods:

A review of 500 malignant pleural effusions, from pulmonary and non-pulmonary sources, was undertaken over a 4-year period. Of these 44 cases (from 42 patients) that were positive for primary lung adenocarcinoma were included in the study. Molecular analysis was performed on 42 specimens. A complete next generation sequencing (NGS) panel was performed on 36 specimens. Individual testing for estimated glomerular filtration rate, KRAS, anaplastic lymphoma kinase, and ROS1 was performed on six specimens. The number of malignant cells and proportion of tumor to non-tumor nucleated cells (T: NT) on cell blocks was recorded as <20%, 20–50% and >50%.

Results:

The minimum volume on which a complete NGS panel could be performed was 20 ml with cell count of 1000 and T: NT proportion of 20–50%. The minimum number of tumor cells required for successful molecular analysis for T: NT proportion of <20%, 20–50%, and >50% was 300, 250, and 170 cells, respectively.

Conclusion:

We concluded that tumor cell proportion, rather than specimen volume, is of prime importance for determining the efficacy of pleural fluid for molecular studies. Evaluation of both absolute and relative numbers of tumor cells is critical for assessing the adequacy and predicting successful yield for molecular analysis.

Cytologic Investigations for the Diagnosis of Malignant Pleural Effusion in Non-small Cell Lung Cancer: State-of-the-art Review for Pulmonologists

Lung cancer is the current leading cause of cancer-related deaths worldwide, and malignant pleural effusion, an indicator of the advanced stage of this disease, portends a poor prognosis. Thus, making an accurate diagnosis of malignant pleural effusion is of paramount importance. During the past decade, the prognosis of patients with advanced non-small cell lung cancer has improved substantially, especially in those treated with targeted therapy and immunotherapy. The use of pleural fluid cytology should not only provide diagnoses but also aid in the selection of targeted therapies, especially when obtaining a histologic specimen is too difficult. In this evidence-based review, we address the importance of pleural fluid cytology in non-small cell lung cancer patients, from making the diagnosis to making treatment-related decisions when only pleural fluid is available.

The Liquid Biopsy for Lung Cancer: State of the Art, Limitations and Future Developments

Simple Summary

During the development and progression of lung tumors, processes such as necrosis and vascular invasion shed tumor cells or cellular components into various fluid compartments. Liquid biopsies consist of obtaining a bodily fluid, typically peripheral blood, in order to isolate and investigate these shed tumor constituents. Circulating tumor cells (CTCs) are one such constituent, which can be isolated from blood and can act as a diagnostic aid and provide valuable prognostic information. Liquid-based biopsies may also have a potential future role in lung cancer screening. Circulating tumor DNA (ctDNA) is found in small quantities in blood and, with the recent development of sensitive molecular and sequencing technologies, can be used to directly detect actionable genetic alterations or monitor for resistance mutations and guide clinical management. While potential benefits of liquid biopsies are promising, they are not without limitations. In this review, we summarize the current state and limitations of CTCs and ctDNA and possible future directions.

Abstract

Lung cancer is a leading cause of cancer-related deaths, contributing to 18.4% of cancer deaths globally. Treatment of non-small cell lung carcinoma has seen rapid progression with targeted therapies tailored to specific genetic drivers. However, identifying genetic alterations can be difficult due to lack of tissue, inaccessible tumors and the risk of complications for the patient with serial tissue sampling. The liquid biopsy provides a minimally invasive method which can obtain circulating biomarkers shed from the tumor and could be a safer alternative to tissue biopsy. While tissue biopsy remains the gold standard, liquid biopsies could be very beneficial where serial sampling is required, such as monitoring disease progression or development of resistance mutations to current targeted therapies. Liquid biopsies also have a potential role in identifying patients at risk of relapse post treatment and as a component of future lung cancer screening protocols. Rapid developments have led to multiple platforms for isolating circulating tumor cells (CTCs) and detecting circulating tumor DNA (ctDNA); however, standardization is lacking, especially in lung carcinoma. Additionally, clonal hematopoiesis of uncertain clinical significance must be taken into consideration in genetic sequencing, as it introduces the potential for false positives. Various biomarkers have been investigated in liquid biopsies; however, in this review, we will concentrate on the current use of ctDNA and CTCs, focusing on the clinical relevance, current and possible future applications and limitations of each.

Clinical Characteristics and Outcome of Pathologic N0 Non-small Cell Lung Cancer Patients With False Positive Mediastinal Lymph Node Metastasis on FDG PET-CT

BACKGROUND/AIM

Preoperative fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET-CT) is a non-invasive and useful diagnostic tool to evaluate mediastinal lymph node (LN) metastasis in lung cancer. However, there are often false-positive LN cases in FDG PET-CT. This study aimed to explore the clinical characteristics and outcome of pathologic N0 non-small cell lung cancer patients with false-positive mediastinal LN on FDG PET-CT.

PATIENTS AND METHODS

We enrolled 147 patients who underwent preoperative FDG PET-CT scan and mediastinal LN dissection. These patients were re-evaluated for post-operative pathologic nodal metastasis and divided into a false-positive group and a group of others.

RESULTS

Among 40 patients diagnosed with clinical N1-3 on FDG PET-CT, 19 (47.5%) patients were pathologic N0, meaning false-positive LN by PET-CT. Preoperative absolute platelet count and platelet-lymphocyte ratio were significantly higher in patients with pathologic N0. The presence of lymphatic invasion was significantly lower in patients with pathologic N0 than in the group of others. Recurrence-free survival was significantly shorter in patients with false positive LN than in patients with true positive LN or true negative LN at the same pathologic stage.

CONCLUSION

Higher absolute platelet count and PLR, lower proportion of lymphatic invasion and shorter recurrence-free survival were associated with false positive mediastinal LN on preoperative FDG PET-CT.

Diving into the Pleural Fluid: Liquid Biopsy for Metastatic Malignant Pleural Effusions

Simple Summary

Malignant pleural effusion is a common complication arising as the natural progression of many tumors, such as lung cancer. When this occurs, the common protocol consists of analyzing the pleural fluid for the presence of malignant cells. However, on many occasions no malignant cells are found despite a clear suspicion of cancer. Thus, the current diagnostic methodology is imperfect and more precise methods for the identification of malignancy are needed. Nonetheless, these methods are often invasive, which may be counterproductive, especially for patients with poor health condition. These concerns have made clinicians consider alternative non-invasive strategies to diagnose cancer using the generally abundant pleural fluid (e.g., liquid biopsy). Thus, a liquid sample can be analyzed for the presence of cancer footprints, such as circulating malignant cells and tumor nucleic acids. Herein, we review the literature for studies considering pleural fluid as a successful source of liquid biopsy.

Abstract

Liquid biopsy is emerging as a promising non-invasive diagnostic tool for malignant pleural effusions (MPE) due to the low sensitivity of conventional pleural fluid (PF) cytological examination and the difficulty to obtain tissue biopsies, which are invasive and require procedural skills. Currently, liquid biopsy is increasingly being used for the detection of driver mutations in circulating tumor DNA (ctDNA) from plasma specimens to guide therapeutic interventions. Notably, malignant PF are richer than plasma in tumor-derived products with potential clinical usefulness, such as ctDNA, micro RNAs (miRNAs) and long non-coding RNAs (lncRNAs), and circulating tumor cells (CTC). Tumor-educated cell types, such as platelets and macrophages, have also been added to this diagnostic armamentarium. Herein, we will present an overview of the role of the preceding biomarkers, collectively known as liquid biopsy, in PF samples, as well as the main technical approaches used for their detection and quantitation, including a proper sample processing. Technical limitations of current platforms and future perspectives in the field will also be addressed. Using PF as liquid biopsy shows promise for use in current practice to facilitate the diagnosis and management of metastatic MPE.

Predictive value of KRAS mutation and excision repair cross-complementing 1 (ERCC1) protein overexpression in patients with colorectal cancer administered FOLFOX regimen

BACKGROUND

Recent studies have reported that KRAS mutational status is correlated with ERCC1 expression level. The purpose of this study was to determine the clinical significance of the KRAS mutation and ERCC1 overexpression status as predictive factors for resistance against oxaliplatin-based treatment.

METHODS

We retrospectively analyzed clinicopathologic features, KRAS mutation status, and ERCC1 overexpression status in 386 patients with colorectal cancer (CRC) who underwent curative-intent surgery. Of these patients, 84 were administered the FOLFOX regimen as a first-line or adjuvant treatment. Disease-free survival and overall survival in groups separated by KRAS and ERCC1 statuses were analyzed.

RESULTS

Wild-type KRAS and ERCC1 overexpression were observed in 25.5% of all patients. Among the 84 patients who were treated with the FOLFOX regimen, 73 patients were evaluated for KRAS and ERCC1 status. There were no significant differences in disease-free survival or overall survival in groups separated by KRAS mutation and ERCC1 expression status. Subgroup analysis of patients with wild-type KRAS showed that overall survival in the ERCC1 overexpression group was lower than that of patients in the ERCC1 underexpression group (p = 0.029); however, no significant difference was found in the mutant KRAS patient group (p = 0.671).

CONCLUSIONS

Our results suggest that CRC with wild-type KRAS and ERCC1 overexpression might be associated with oxaliplatin resistance. When considering oxaliplatin-based chemotherapy, the status of both KRAS mutation and ERCC1 overexpression should be evaluated.

Impact of Combined Chronic Obstructive Pulmonary Disease Status and Systemic Inflammation on Outcome of Advanced NSCLC: Multicenter Retrospective Cohort Study

Background

In patients with non-small cell lung cancer (NSCLC), both chronic obstructive pulmonary disease (COPD) and systemic inflammatory biomarkers, such as neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), have significant association with prognosis. NLR and PLR also predict mortality in patients with COPD alone. A combination of the two parameters may be helpful in a more individualized approach for predicting prognosis in NSCLC.

Methods

Medical records of patients with stage IIIB and IV NSCLC from January 2012 to January 2018 in seven university hospitals were reviewed. Patients were categorized into four subgroups based on pulmonary function test results and cutoffs for NLR or PLR.

Results

A total of 277 patients were evaluated and categorized into non-COPD and COPD groups; 194 patients were in the non-COPD group and 83 patients were in the COPD group. The non-COPD group showed significantly longer overall survival (OS) compared with the COPD group (P = 0.019). Median survival was significantly different between high/low PLR groups (P < 0.001), between high/low NLR groups (P = 0.001), and between high/low c-reactive protein (CRP) groups (P < 0.001). PLR, NLR and CRP showed significant correlations with each other. PLR showed a significant negative linear correlation with FVC (absolute) (r = −0.149, P = 0.015), FVC (%) (r = −0.192, P = 0.002), DLCO (absolute) (r = −0.271, P < 0.001), DLCO (%) (r = −0.139, P = 0.032), and NLR (r = 0.718, P < 0.001). In the multivariate analysis, the high PLR, COPD sub-group showed significantly higher risk for mortality (HR 2.066 (1.175–3.633), P = 0.012) compared with the low-PLR non-COPD group. However, COPD-NLR subtype was not an independent predictor for OS.

Conclusion

A combination of COPD status and PLR may be a cost-effective and readily available prognostic marker in patients with advanced NSCLC.

Liquid biopsy approaches for pleural effusion in lung cancer patients

Genomic profiling of tumors has become the mainstay for diagnosis, treatment monitoring and a guide to precision medicine. However, in clinical practice, the detection of driver mutations in tumors has several procedural limitations owing to progressive disease and tumor heterogeneity. The current era of liquid biopsy promises a better solution. This diagnostic utility of liquid biopsy has been demonstrated by numerous studies for the detection of cell-free DNA (cfDNA) in plasma for disease diagnosis, prognosis, and prediction. However, cfDNAs are limited in blood circulation and still hurdles to achieve promising precision medicine. Malignant pleural effusion (MPE) is usually detected in advanced lung malignancy, which is rich in tumor cells. Extracellular vesicles and cfDNAs are the two major targets currently explored using MPE. Therefore, MPE can be used as a source of biomarkers in liquid biopsy for investigating tumor mutations. This review focuses on the liquid biopsy approaches for pleural effusion which may be explored as an alternative source for liquid biopsy in lung cancer patients to diagnose early disease progression.

Impact of smoking amount on clinicopathological features and survival in non-small cell lung cancer

BACKGROUND

Screening for early detection of lung cancer has been performed in high-risk individuals with smoking history. However, researches on the distribution, clinical characteristics, and prognosis of these high-risk individuals in an actual cohort are lacking. Thus, the objective of this study was to retrospectively review characteristics and prognosis of patients with smoking history in an actual lung cancer cohort.

METHODS

The present study used the lung cancer cohort of the Catholic Medical Centers at the Catholic University of Korea from 2014 to 2017. Patients with non-small cell lung cancer were enrolled. They were categorized into high and low-risk groups based on their smoking history using the national lung screening trial guideline. Distribution, clinical characteristics, and survival data of each group were estimated.

RESULTS

Of 439 patients, 223 (50.8%) patients were in the high-risk group. Patients in the high-risk group had unfavorable clinical characteristics and tumor biologic features. Overall survival of the high-risk group was significantly shorter than that of the low-risk group with both early (I, II) and advanced stages (III, IV). In multivariate analysis, heavy smoking remained one of the most important poor clinical prognostic factors in patients with lung cancer. It showed a dose-dependent relationship with patients' survival.

CONCLUSIONS

High-risk individuals had poor clinical outcomes. Patients' prognosis seemed to be deteriorated as smoking amount increased. Therefore, active screening and clinical attention are needed for high-risk individuals.

Current applications of molecular testing on body cavity fluids

INTRODUCTION

Effusion cytology has a high sensitivity for the diagnosis of malignancy and provides abundant material for molecular testing. Effusion draining is a minimally invasive procedure with few complications.

MATERIALS AND METHODS

We performed a review of publications regarding the use of molecular testing in serous effusions.

RESULTS

In diagnostics, BAP-1 IHC and CDKN2A FISH are powerful tools for the diagnosis of malignant mesothelioma. FISH, PCR, and EBER-ISH work well in lymphomas. RT-PCR may enhance the diagnosis of secondary epithelial malignancies. In theranostics, molecular testing on serous effusions is widely reported for the detection of alterations in genes related to lung carcinomas, such as EGFR, ALK, ROS1, and BRAF. PD-L1 expression testing by immunohistochemistry (IHC) also seems to be viable in this type of sample. HER2 FISH and IHC provide actionable results in the context of breast malignancies. Results in serous effusions seem to be equivalent to tissue biopsies for most applications and across different molecular techniques. The most interesting technology is next-generation sequencing (NGS), given its ability to sequence multiple genes on a single sample and the decreasing costs that have closely followed increasing throughputs. Cell-free DNA from effusion supernatants might be the most promising area for future research, showing superiority to serum and even to cell-block samples in limited studies.

CONCLUSIONS

Molecular tests are viable in serous effusion specimens when sufficient material is available. Given the rising importance of molecular testing we expect this to be an active field of research in the near future.

Analysis of EGFR mutation status in malignant pleural effusion and plasma from patients with advanced lung adenocarcinoma

Background

Cell-free DNA (cfDNA) is emerging as a surrogate sample type for mutation analyses. We investigated the suitability of malignant pleural effusion (MPE) and plasma as a biomaterial for analyzing epidermal growth factor receptor (EGFR) mutation by peptide nucleic acid (PNA) clamping-assisted fluorescence melting curve (PANAMutyper™) analysis.

Methods

Matched tissue, MPE cell block (MPE-CB), MPE supernatant, and plasma samples were collected from patients with advanced lung adenocarcinoma who had a MPE at the time of diagnosis. EGFR mutation was assessed by PANAMutyper™.

Results

Mutation analyses in matched tumor tissues, MPE-CB, MPE supernatant, and/or plasma samples were available for 67 patients. In comparison with tumor tissue and MPE-CB, MPE supernatant exhibited 84.4% sensitivity, 97.1% specificity, 96.4% positive predictive value (PPV), and 87.2% negative predictive value (NPV). In the same comparison, plasma exhibited 70.6% sensitivity, 100.0% specificity, 100.0% PPV, and 73.7% NPV. When sorted by mutation type, MPE supernatant had better sensitivity than plasma for the detection of two major EGFR mutations: 93.8% vs. 75.0% for exon 19 deletion and 73.3% vs. 60.0% for L858R.

Conclusions

In this cohort of patients with MPEs, MPE supernatant demonstrated superior diagnostic performance compared with plasma using a PNA-based real-time PCR method.

Tumor circulome in the liquid biopsies for cancer diagnosis and prognosis

Liquid biopsy is a convenient, fast, non-invasive and reproducible sampling method that can dynamically reflect the changes in tumor gene expression profile, and provide a robust basis for individualized therapy and early diagnosis of cancer. Circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs) are the currently approved diagnostic biomarkers for screening cancer patients. In addition, tumor-derived extracellular vesicles (tdEVs), circulating tumor-derived proteins, circulating tumor RNA (ctRNA) and tumor-bearing platelets (TEPs) are other components of liquid biopsies with diagnostic potential. In this review, we have discussed the clinical applications of these biomarkers, and the factors that limit their implementation in routine clinical practice. In addition, the most recent developments in the isolation and analysis of circulating tumor biomarkers have been summarized, and the potential of non-blood liquid biopsies in tumor diagnostics has also been discussed.

Multiplexed molecular profiling of lung cancer with malignant pleural effusion using next generation sequencing in Chinese patients

Lung cancer is the most common type of cancer and the leading cause of cancer-associated death worldwide. Malignant pleural effusion (MPE), which is observed in ~50% of advanced non-small cell lung cancer (NSCLC) cases, and most frequently in lung adenocarcinoma, is a common complication of stage III-IV NSCLC, and it can be used to predict a poor prognosis. In the present study, multiple oncogene mutations were detected, including 17 genes closely associated with initiation of advanced lung cancer, in 108 MPE samples using next generation sequencing (NGS). The NGS data of the present study had broader coverage, deeper sequencing depth and higher capture efficiency compared with NGS findings of previous studies on MPE. In the present study, using NGS, it was demonstrated that 93 patients (86%) harbored EGFR mutations and 62 patients possessed mutations in EGFR exons 18-21, which are targets of available treatment agents. EGFR L858R and exon 19 indel mutations were the most frequently observed alterations, with frequencies of 31 and 25%, respectively. In 1 patient, an EGFR amplification was identified and 6 patients possessed a T790M mutation. ALK + EML4 gene fusions were identified in 6 patients, a ROS1 + CD74 gene fusion was detected in 1 patient and 10 patients possessed a BIM (also known as BCL2L11) 2,903-bp intron deletion. In 4 patients, significant KRAS mutations (G12D, G12S, G13C and A146T) were observed, which are associated with resistance to afatinib, icotinib, erlotinib and gefitinib. There were 83 patients with ERBB2 mutations, but only two of these mutations were targets of available treatments. The results of the present study indicate that MPE is a reliable specimen for NGS based detection of somatic mutations.

Molecular Profiling for Supernatants and Matched Cell Pellets of Pleural Effusions in Non-Small-Cell Lung Cancer

Pleural effusion (PE) is commonly observed in advanced lung cancer patients. Cell-free total nucleic acid (cfTNA) isolated from cancer patients' plasma has allowed noninvasive tumor genome analyses; however, there are limited studies of detection and characterization of cfTNA in PE. Herein, we included 47 advanced non-small-cell lung cancer patients with PE, who had lung cancer driver mutations tested on tumor tissue specimens either at diagnosis or during disease progression. The supernatant and cell pellet of each PE were evaluated for molecular profiles in parallel on an Ion Torrent next-generation sequencing platform. Somatic mutations were detected in 89.1% supernatant cfTNA, but in only 54.3% of cell pellets. The overall concordance rate between supernatants and formalin-fixed, paraffin-embedded cell pellets at the mutation level was 53.3%. By contrast, 41.7% and 5.0% of somatic alterations were detected in supernatants and cell pellets, respectively. Furthermore, joint analysis of supernatants and cell pellets from PE showed a high concordance (88.3%) of variant detection with their respective tumor tissue specimens. Low-frequency T790M mutations in three cases (0.29%, 0.41%, and 1.56%) were detected in supernatants but not in the matched cell pellets or tumor tissues. In conclusion, pleural effusion-derived cfTNA can effectively be used in clinical practice for molecular analysis by next-generation sequencing, even in cases where corresponding cell pellets or tumor tissues yield insufficient material.

Proceedings of the American Society of Cytopathology companion session at the 2019 United States and Canadian Academy of Pathology Annual meeting, part 2: effusion cytology with focus on theranostics and diagnosis of malignant mesothelioma

We live in the "era" of minimally invasive procedures, molecular testing, and personalized care. Effusions have a high sensitivity and will often yield diagnostic cytological material. The companion session presented by the American Society of Cytopathology at the 2019 United States and Canadian Academy of Pathology meeting outlined our current and future projected practices in characterizing, managing, and diagnosing serous cavity fluids. In this second part, the role of theranostics and the diagnosis of malignant mesothelioma, as was discussed at the meeting, have been highlighted. In theranostics, a vast amount of data has been reported regarding the epidermal growth factor receptor and related molecules. Some studies have also reported on HER2 immunohistochemistry and fluorescence in situ hybridization. This follows the most active areas of research in targeted therapy. Furthermore, during this session, malignant mesothelioma was extensively discussed. The cytologic diagnosis of malignant mesothelioma in effusion specimens has been controversial; however, a definitive diagnosis will be possible in many cases. Radiologic information should be sought, because the radiologist can often provide a definite or very likely diagnosis of malignancy. Microscopically, high cellularity and/or numerous balls of cells or papillary groups will favor the diagnosis of mesothelioma. It is important to exclude metastatic carcinoma with a broad-spectrum carcinoma marker, of which claudin-4 has been the best, because it will not cross react with mesothelioma. BAP1 and MTAP immunohistochemistry and CDKN2A fluorescence in situ hybridization are very useful adjunctive techniques for separating benign from malignant mesothelial proliferations. The use of 2 of these approaches together will produce a sensitivity of 80% to 90% for epithelial mesotheliomas in the pleura, although the sensitivity has been lower in the peritoneal cavity.

Comparison of cobas EGFR Mutation Test v2 and PANAMutyper-R-EGFR for Detection and Semi-Quantification of Epidermal Growth Factor Receptor Mutations in Plasma and Pleural Effusion Supernatant

Background

Plasma epidermal growth factor receptor (EGFR) mutation tests are less invasive than tissue EGFR mutation tests. We determined which of two kits is more efficient: cobas EGFR Mutation test v2 (cobasv2; Roche Molecular Systems, Pleasanton, CA, USA) or PANAMutyper-R-EGFR (Mutyper; Panagene, Daejeon, Korea). We also evaluated whether pleural effusion supernatant (PE-SUP) samples are assayable, similar to plasma samples, using these two kits.

Methods

We analyzed 156 plasma and PE-SUP samples (31 paired samples) from 116 individuals. We compared the kits in terms of accuracy, assessed genotype concordance (weighted κ with 95% confidence intervals), and calculated Spearman's rho between semi-quantitatively measured EGFR-mutant levels (SQIs) measured by each kit. We also compared sensitivity using 47 EGFR-mutant harboring samples divided into more-dilute and less-dilute samples (dilution ratio: ≥ or <1:1,000).

Results

cobasv2 tended to have higher accuracy than Mutyper (73% vs 69%, P=0.53), and PE-SUP samples had significantly higher accuracy than plasma samples (97% vs 55–71%) for both kits. Genotype concordance was 98% (κ=0.92, 0.88–0.96). SQIs showed strong positive correlations (P<0.0001). In less-dilute samples, accuracy and sensitivity did not differ significantly between kits. In more-dilute samples, cobasv2 tended to have higher sensitivity than Mutyper (43% vs 20%, P=0.07).

Conclusions

The kits have similar performance in terms of EGFR mutation detection and semi-quantification in plasma and PE-SUP samples. cobasv2 tends to outperform Mutyper in detecting less-abundant EGFR-mutants. PE-SUP samples are assayable using either kit.

Cytological-negative pleural effusion can be an alternative liquid biopsy media for detection of EGFR mutation in NSCLC patients

OBJECTIVE

Though the possibility of using malignant pleural effusions (MPEs) as alternatives for tumor tissues in epidermal growth factor receptor (EGFR) mutation test has been examined, the diagnosis of MPE is often clinically challenging, especially if the cytology is negative for malignancy. The aim of this study was to examine whether cytological-negative PE (CNPE) is useful in detecting EGFR mutation and evaluated its feasibility for predicting clinical outcomes.

METHOD

In this study, we performed capture-based targeted sequencing using a panel consisting of 520 lung cancer-related genes to detect EGFR mutation status in 121 MPEs and 40 CNPE samples from 161 advanced lung adenocarcinoma patients. Patients underwent TKI treatment with gefitinib, icotinib or erlotinib if EGFR sensitizing mutations were detected at their tumor biopsies or pleural effusion sediment.

RESULTS

We revealed a mutation detection rate of 99.2% and 100% for MPE and CNPE, respectively (p = 1). The maximum allelic fraction (maxAF) of MPE and CNPE were 57.4% and 56.8%, respectively (p = 0.77). CNPE supernatant is comparable to MPE in reflecting the mutational profile of lung adenocarcinoma. EGFR activating mutations were detected in 47.5% (19/40) of CNPE supernatant sample and 32.5% (13/40) of matched tumor biopsies. CNPE sample is superior to tumor tissues in identifying EFGR mutation. Among the 72 EGFR-TKI treated patients, 51 were cytology positive and the remaining 21 were cytology negative. Our data showed that MPE patients exhibited comparable PFS (p = 0.41) and OS (p = 0.26) with CNPE patients treated with EGFR-TKI. Among the 21 CNPE patients received TKI treatment, patients harboring either L858R or exon 19 deletion had longer PFS than patients without a detectable mutation (p = 0.036).

CONCLUSION

Collectively, we demonstrated that CNPE supernatant provided a comprehensive profile of NSCLC, and can serve as a reliable lipid biopsy media for EGFR mutational detection.

Comparison of PNA Clamping-assisted Fluorescence Melting Curve Analysis and PNA Clamping in Detecting EGFR Mutations in Matched Tumor Tissue, Cell Block, Pleural Effusion and Blood of Lung Cancer Patients With Malignant Pleural Effusion

BACKGROUND/AIM

This study compared the efficacy of PANAMutyper™, a novel technology that integrates PNAClamp™ and PANA S-Melting™, and PNAClamp™ alone for the detection of EGFR mutations in lung cancer patients.

MATERIALS AND METHODS

PANAMutyper™ and PNAClamp™ were used to assess the EGFR mutation status in tissue, cell block, pleural effusion, and blood samples of 90 lung cancer patients with malignant pleural effusion.

RESULTS

PANAMutyper™ detected more EGFR mutations than PNAClamp™, especially in body fluids (pleural effusion and serum). Patients with additional EGFR mutations detected using PANAMutyper™ had a favorable response to EGFR-tyrosine kinase inhibitor (TKI) treatment.

CONCLUSION

The diagnostic performance of PANAMutyper™ was superior to that of PNAClamp™ for the detection of EGFR mutations. It was also better at identifying lung cancer patients with malignant pleural effusion who were likely to benefit from EGFR-TKI treatment.

Pleural effusion as a substitute for tumor tissue in detecting EGFR/ALK mutations in non-small cell lung cancer: A systematic review and meta-analysis

BACKGROUND

Pleural effusion (PE) has been reported useful in many studies for testing epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) with variable results. This systematic review and meta-analysis was performed to elucidate whether PE could be used as a surrogate for tumor tissue to detect EGFR mutations.

METHODS

We extracted 2 × 2 diagnostic table from each included study and calculated data on specificity, sensitivity, negative likelihood ratio (NLR), positive likelihood ratio (PLR) ,and diagnostic odds ratio (DOR). We used the area under curve (AUC) and summary receiver operating characteristic curve (SROC) to summarize the overall diagnostic performance and assessed publication bias by Deeks' funnel plot.

RESULTS

Our meta-analysis included 15 eligible publications. The following summary estimates for diagnostic parameters of the EGFR mutations detection in PE were made: sensitivity, 0.86 (95%CI 0.83-0.89); specificity, 0.93 (95%CI 0.91-0.95); PLR, 8.53 (95%CI 5,94-12.25); NLR, 0.18 (95%CI 0.13-0.25); DOR, 63.40 (95%CI 38.83-103.51); and AUC, 0.94. Funnel plot indicated publication bias insignificant.

CONCLUSIONS

The meta-analysis suggests that EGFR mutation detecting in PE, especially supernatants, is a promising surrogate for tumor tissue in EGFR mutations testing of patients with NSCLC.

Comparison of PANAMutyper and PNAClamp for Detecting KRAS Mutations from Patients With Malignant Pleural Effusion

BACKGROUND/AIM

KRAS is one of the frequently mutated genes in human cancers and often relates with drug resistance and poor prognosis. PANAMutyper™ is a novel technology that integrates PNAClamp™ and PANA S-Melting™. In the present study, PANAMutyper™ and PNAClamp™ were compared for the detection of KRAS mutations using different samples of patients with malignant pleural effusion.

PATIENTS AND METHODS

A total of 103 patients (including 56 lung adenocarcinoma, 10 lung squamous carcinoma, 17 small cell lung cancer, 3 large cell lung cancer, 3 stomach cancer, 2 ovarian cancer, and others) with malignant pleural effusion were investigated using matched tumor tissue, cell block, and pleural effusion samples. The diagnostic performance of these two methods was compared.

RESULTS

KRAS mutations were detected in 18 (17.5%) of 103 patients using tissue, cell block, and pleural effusion samples. All 18 patients with KRAS mutations were detected by PANAMutyper™ using any sample type, however, only 7 cases were detected by PNAClamp™. Among the subtypes of KRAS mutations, substitution in codon 12, 35G>T was the most frequent, followed by substitution in codon 12, 35G>A and codon 12, 34G>A. In pleural effusion specimens, PANAMutyper™ showed a better diagnostic performance compared to PNAClamp™.

CONCLUSION

PANAMutyper™ had a diagnostic superiority for the detection of KRAS mutations in patients with malignant pleural effusion compared to PNAClamp™, although there was a concordance between PANAMutyper™ and PNAClamp™ results. Therefore, PANAMutyper™ can be used for a more sensitive and accurate detection of KRAS mutations.

Elevated pretreatment platelet-to-lymphocyte ratio is associated with poor survival in stage IV non-small cell lung cancer with malignant pleural effusion

A higher platelet-to-lymphocyte ratio (PLR) has a clinical correlation with shorter survival in non-small cell lung cancer (NSCLC). The present study evaluated the association between the PLR and survival in patients with advanced NSCLC with malignant pleural effusion (MPE). Between January 2012 and July 2016, 237 patients with stage IV NSCLC were selected for evaluation. Receiver operating characteristic analysis was used to determine a cutoff for the PLR. Clinicopathological characteristics were compared between the high and low PLR groups, and the role of PLR as a predictive/prognostic maker was investigated. Among the 237 patients, 122 were assigned to the low PLR group and the other 115 to the high PLR group. According to multivariate analysis, male sex, not receiving active anticancer treatment, low hemoglobin level, low albumin level, high C-reactive protein level, and high PLR were identified as significant risk factors for shorter overall survival (OS) (p = 0.010, <0.001, 0.011, 0.004, 0.003, and <0.001, respectively). In the subgroup multivariate analysis of driver mutation-negative NSCLC, high Eastern Cooperative Oncology Group score, not receiving active anticancer treatment, low hemoglobin level, high C-reactive protein level, and high PLR were identified as significant risk factors for shorter OS (p = 0.047, <0.001, = 0.036, = 0.003, and <0.001, respectively). A high pretreatment PLR is independently associated with poor survival in stage IV NSCLC with MPE and in a subgroup of epidermal growth factor receptor and anaplastic lymphoma kinase wild-type NSCLC.

Molecular analysis of small tissue samples obtained via transbronchial lung biopsy using radial probe endobronchial ultrasound

BACKGROUND

Radial probe endobronchial ultrasound using a guide sheath (EBUS-GS) is used to diagnose peripheral lung cancer. The aim was to identify the accuracy of molecular analysis that were performed with EBUS-GS specimens in patients with non-small cell lung cancer (NSCLC).

METHOD

From December 2015 to September 2017, we retrospectively studied 91 patients with peripheral NSCLC who underwent surgery after EBUS-GS. Epidermal growth factor receptor (EGFR) mutational and anaplastic lymphoma kinase (ALK) translocation status obtained from surgical specimens served as the references.

RESULTS

Compared to the reference data, EGFR mutational testing of EBUS-GS specimens was in 97% agreement, and the κ coefficient was 0.931 (P< 0.001). In addition, on ALK translocation testing, the results of all 91 patients were in agreement with the reference data (concordance rate of 100%, κ coefficient 1.000; P< 0.001).

CONCLUSION

We found that EBUS-GS could be used for molecular diagnosis, such as EGFR mutational and ALK translocation status, in patients with peripheral NSCLC.

Liquid Biopsies in Cancer Diagnosis, Monitoring, and Prognosis

Liquid biopsies, comprising the noninvasive analysis of circulating tumor-derived material (the 'tumor circulome'), represent an innovative tool in precision oncology to overcome current limitations associated with tissue biopsies. Within the tumor circulome, circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs) are the only components the clinical application of which is approved by the US Food and Drug Administration (FDA). Extracellular vesicles (EVs), circulating tumor RNA (ctRNA), and tumor-educated platelets (TEPs) are relatively new tumor circulome constituents with promising potential at each stage of cancer management. Here, we discuss the clinical applications of each element of the tumor circulome and the prevailing factors that currently limit their implementation in clinical practice. We also detail the most recent technological developments in the field, which demonstrate potential in improving the clinical value of liquid biopsies.

[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。

Next generation sequencing-based molecular profiling of lung adenocarcinoma using pleural effusion specimens

Background

Molecular profiling of non-small cell lung cancer (NSCLC) is essential for therapeutic decision-making. Pleural effusion obtained by a non-invasive, repeatable procedure may provide an opportunity for molecular profiling and thereby possibly provide information enabling targeted therapy. In this study, we aimed to evaluate the diagnostic performance of pleural effusion as a specimen for molecular analysis.

Methods

Thirty patients with paired malignant pleural effusion and thoracic biopsy specimens were included. Clinically actionable mutations were assessed using a validated targeted next generation sequencing assay. EGFR/KRAS/ALK mutation status in thoracic biopsy specimens was tested using ARMS PCR.

Results

The concordance rate between gene status identified by ARMS and next-generation sequencing (NGS) analysis in the thoracic biopsy and pleural effusion samples was 86.7% (26/30). Compared with the thoracic biopsy specimens, the diagnostic performance of pleural effusion showed a sensitivity of 92.3%, a specificity of 50.0%, and a positive predictive value of 92.3%. Therefore, cases with a low percentage of tumor cells (<5%) can successfully be used to detect actionable mutations in pleural effusion specimens.

Conclusions

These results suggest that pleural effusions are suitable specimens for oncogene mutation analysis and enable targeted therapy for patients with advanced NSCLC.

Peptide Nucleic Acid Clamping and Direct Sequencing in the Detection of Oncogenic Alterations in Lung Cancer: Systematic Review and Meta-Analysis

PURPOSE

Molecular testing in non-small cell lung cancer (NSCLC) aids in identifying oncogenic alterations. The aim of this study was to compare the rates of detection of oncogenic alterations and responsiveness to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) according to EGFR mutation status as determined by peptide nucleic acid (PNA) clamping or direct sequencing (DS).

MATERIALS AND METHODS

We performed a systematic literature search using MEDLINE, EMBASE, and the Cochrane Central Register. Data from included studies were pooled to yield summary sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratio, and receiver operating characteristic curves. A meta-regression analysis was conducted to identify potential sources of heterogeneity between selected studies.

RESULTS

We identified 10 studies comprising 924 patients. Oncogenic alterations were detected in 340 of 924 cases (36.8%) with PNA clamping and in 250 of 924 (27.1%) with DS. The pooled sensitivities of PNA clamping and DS were 0.93 [95% confidence interval (CI): 0.90-0.95] and 0.69 (95% CI: 0.64-0.73), respectively. According to meta-regression analysis, none of the covariates were found to be significant sources of heterogeneity. With respect to treatment responses to EGFR-TKIs, there was no significant difference therein between EGFR mutations detected by PNA clamping and DS (53.4% vs. 50.8%; risk ratio, 0.99; 95% CI 0.83-1.19; p=0.874).

CONCLUSION

We demonstrated that PNA clamping has a higher sensitivity than DS for detecting oncogenic alterations in NSCLC. Our findings suggest that PNA clamping is a more useful method for clinical practice.

Quantification of mutant alleles in circulating tumor DNA can predict survival in lung cancer

Purpose

We aimed to investigate the feasibility of droplet digital PCR (ddPCR) for the quantitative and dynamic detection of EGFR mutations and next generation sequencing (NGS) for screening EGFR-tyrosine kinase inhibitors (EGFR-TKIs) resistance-relevant mutations in circulating tumor DNA (ctDNA) from advanced lung adenocarcinoma (ADC) patients.

Results

Detection limit of EGFR mutation in ctDNA by ddPCR was 0.04%. Taking the EGFR mutation in tumor tissue as the golden standard, the concordance of EGFR mutations detected in ctDNA was 74% (54/73). Patients with EGFR mutation in ctDNA (n = 54) superior progression-free survival (PFS, median, 12.6 vs. 6.7 months, P < 0.001) and overall survival (OS, median, 35.6 vs. 23.8 months, P = 0.028) compared to those with EGFR wild type in ctDNA (n = 19). Patients with high EGFR-mutated abundance in ctDNA (> 5.15%) showed better PFS compared to those with low EGFR mutated abundance (≤ 5.15%) (PFS, median, 15.4 vs. 11.1 months, P = 0.021). NGS results showed that 66.6% (8/12) total mutational copy number were elevated and 76.5% (26/34) mutual mutation frequency increased after disease progression.

Methods

Seventy-three advanced ADC patients with tumor tissues carrying EGFR mutations and their matched pre- and post-EGFR-TKIs plasma samples were enrolled in this study. Absolute quantities of plasma EGFR mutant and wild-type alleles were measured by ddPCR. Multi-genes testing was performed using NGS in 12 patients.

Conclusions

Dynamic and quantitative analysis of EGFR mutation in ctDNA could guide personalized therapy for advanced ADC. NGS shows good performance in multiple genes testing especially novel and uncommon genes.

Predicting outcomes of EGFR-targeted therapy in non-small cell lung cancer patients using pleural effusions samples and peptide nucleic acid probe assay

BACKGROUND

Mutation of epidermal growth factor receptor (EGFR) is a prediction marker of the response to tyrosine kinase inhibitor (TKI) drugs in non-small cell lung cancer (NSCLC) patients. As late stage lung cancer patients rarely undergo surgery, samples for EGFR mutation identification usually come from computed tomography (CT)-guided or endoscopic biopsies, which is invasive and costly. Pleural effusion may serve as a less invasive sample for EGFR mutation detection.

METHODS

We designed a fluorophore-labeled peptide nucleic acid (PNA) probe assay for three types of EGFR mutations, including exon 19 deletions, L858R point mutations and T790M point mutations. The assay was applied in 39 pleural effusion samples from NSCLC patients. The correlation between detected EGFR status and clinical outcome were analyzed.

RESULTS

In 15 paired samples, PNA probe assay in pleural effusion samples could detect all the mutations that were identified by conventional PCR plus Sanger sequencing in tissue biopsies. In addition, PNA probe assay detected three more T790M mutations. In all 39 pleural effusions, the PNA probe assay detected 27 having at least one of the three EGFR mutations. Among the patients before TKI treatment, those with a sensitizing mutation (either exon 19 deletion or L858R) but without T790M, had 94.1% response rate and longer progression-free survival (mean 10.8 months) than patients without detected mutation (mean 4.2 months) and patients with T790M (mean 1.7 months).

CONCLUSIONS

Mutations detected in pleural effusions using PNA probe assay are highly associated with clinical outcome. This method appears to be a reliable way for the prediction of the efficacy of EGFR-targeted therapy.

Malignant pleural effusions because of lung cancer

PURPOSE OF REVIEW

The discovery of a pleural effusion in the setting of lung cancer has diagnostic, prognostic, and therapeutic challenges, some of which are addressed in this review.

RECENT FINDINGS

Around 20% of patients with lung cancer have minimal pleural effusions, which are not amenable to a diagnostic thoracentesis. These patients have a poorer overall survival (∼7.5 months) than those without effusions (∼12-18 months), although slightly better than those with proven malignant fluids (∼5.5 months). Tumor genotype techniques are feasible on pleural fluid specimens and clinically helpful in identifying patients who may benefit from targeted therapies. If limited pleural involvement is detected during lung cancer surgery despite the presurgical imaging studies, macroscopic complete resection of the lung tumor is still a treatment option. Cytological examination for cancer cells in pleural cavity washings at the time of thoracotomy (pleural lavage cytology) is recommended to uncover pleural dissemination. Patients with non-small cell lung cancer with visceral pleural invasion might be considered candidates for postsurgical adjuvant therapy.

SUMMARY

Some predictors of adverse survival in patients with lung cancer include the presence of a minimal pleural effusion, positive pleural lavage cytology, visceral pleural invasion on pathologic examination, and unexpected pleural involvement during surgery.

EGFR Mutation Status in Lung Adenocarcinoma-Associated Malignant Pleural Effusion and Efficacy of EGFR Tyrosine Kinase Inhibitors

Purpose

Malignant pleural effusions (MPEs) are often observed in lung cancer, particularly adenocarcinoma. The aim of this study was to investigate epidermal growth factor receptor (EGFR) mutation status in lung adenocarcinoma-associated MPEs (LA-MPEs) and its correlation with efficacy of EGFR tyrosine kinase inhibitor (TKI) therapy.

Materials and Methods

Samples comprised 40 cell blocks of pathologically-confirmed LA-MPEs collected before the start of EGFR TKI therapy. EGFR mutation status was re-evaluated by peptide nucleic acid clamping and the clinical outcomes of EGFR TKI‒treated patients were analyzed retrospectively.

Results

EGFR mutations were detected in 72.5% of LA-MPE cell blocks (29/40). The median progression-free survival for patients with EGFR mutations in LA-MPEs was better than that for patients with wild-type EGFR (7.33 months vs. 2.07 months; hazard ratio, 0.486; 95% confidence interval, 0.206 to 1.144; p=0.032). The objective response rate (ORR) of 26 patients with EGFR mutations in LA-MPEs among the 36 patients with measurable lesions was 80.8%, while the ORR of the 10 patients with wild-type EGFR in LA-MPEs was 10% (p < 0.001). Among the 26 patients with EGFR mutations in LA-MPEs, the ORR of target lesions and LA-MPEs were 88.5% and 61.5%, respectively (p=0.026).

Conclusion

EGFR mutation status in cell blocks of LA-MPEs confirmed by pathologic diagnosis is highly predictive of EGFR TKI efficacy. For patients with EGFR mutations in LA-MPEs, the response to EGFR TKIs seems to be worse for pleural effusions than for solid tumors.

Non-blood circulating tumor DNA detection in cancer

Tumor DNA contains specific somatic alterations that are crucial for the diagnosis and treatment of cancer. Due to the spatial and temporal intra-tumor heterogeneity, multi-sampling is needed to adequately characterize the somatic alterations. Tissue biopsy, however, is limited by the restricted access to sample and the challenges to recapitulate the tumor clonal diversity. Non-blood circulating tumor DNA are tumor DNA fragments presents in non-blood body fluids, such as urine, saliva, sputum, stool, pleural fluid, and cerebrospinal fluid (CSF). Recent studies have demonstrated the presence of tumor DNA in these non-blood body fluids and their application to the diagnosis, screening, and monitoring of cancers. Non-blood circulating tumor DNA has an enormous potential for large-scale screening of local neoplasms because of its non-invasive nature, close proximity to the tumors, easiness and it is an economically viable option. It permits longitudinal assessments and allows sequential monitoring of response and progression. Enrichment of tumor DNA of local cancers in non-blood body fluids may help to archive a higher sensitivity than in plasma ctDNA. The direct contact of cancerous cells and body fluid may facilitate the detection of tumor DNA. Furthermore, normal DNA always dilutes the plasma ctDNA, which may be aggravated by inflammation and injury when very high amounts of normal DNA are released into the circulation. Altogether, our review indicate that non-blood circulating tumor DNA presents an option where the disease can be tracked in a simple and less-invasive manner, allowing for serial sampling informing of the tumor heterogeneity and response to treatment.

Longitudinal monitoring of EGFR mutations in plasma predicts outcomes of NSCLC patients treated with EGFR TKIs: Korean Lung Cancer Consortium (KLCC-12-02)

We hypothesized that plasma-based EGFR mutation analysis for NSCLC may be feasible for monitoring treatment response to EGFR TKIs and also predict drug resistance. Clinically relevant mutations including exon 19 deletion (ex19del), L858R and T790M were analyzed using droplet digital PCR (ddPCR) in longitudinally collected plasma samples (n = 367) from 81 NSCLC patients treated with EGFR TKI. Of a total 58 baseline cell-free DNA (cfDNA) samples available for ddPCR analysis, 43 (74.1%) had the same mutation in the matched tumors (clinical sensitivity: 70.8% [17/24] for L858R and 76.5% [26/34] for ex19del). The concordance rates of plasma with tissue-based results of EGFR mutations were 87.9% for L858R and 86.2% for ex19del. All 40 patients who were detected EGFR mutations at baseline showed a dramatic decrease of mutant copies (>50%) in plasma during the first two months after treatment. Median progression-free survival (PFS) was 10.1 months for patients with undetectable EGFR v 6.3 months for detectable EGFR mutations in blood after two-month treatment (HR 3.88, 95% CI 1.48-10.19, P = 0.006). We observed emerging resistance with early detection of T790M as a secondary mutation in 14 (28.6%) of 49 patients. Plasma-based EGFR mutation analysis using ddPCR can monitor treatment response to EGFR TKIs and can lead to early detection of EGFR TKIs resistance. Further studies confirming clinical implications of EGFR mutation in plasma are warranted to guide optimal therapeutic strategies upon knowledge of treatment response and resistance.

Pre-analytical issues in effusion cytology

Effusions or body cavity fluids are amongst the most commonly submitted samples to the cytology laboratory. Knowledge of proper collection, storage, preservation and processing techniques is essential to ensure proper handling and successful analysis of the sample. This article describes how the effusions should be collected and proper conditions for submission. The different processing techniques to extract the cellular material and prepare slides satisfactory for microscopic evaluation are described such as direct smears, cytospins, liquid based preparations and cell blocks. The article further elaborates on handling the specimens for additional ancillary testing such as immunostaining and molecular tests, including predictive ones, as well as future research approaches.

Analysis of an EGFR mutation by PNA clamping method in lung carcinoid tumors

Background Pulmonary carcinoid tumors consisting of typical carcinoid tumors (TC) and atypical carcinoid tumors (AC) are rare, accounting for 2–5% of all lung tumors. TC is considered a low-grade tumor with a rate of distant metastasis up to 12%. In contrast, ACs are more aggressive tumors, displaying a metastatic rate up to 70%. Surgery is the treatment of choice; however, the current treatment outcomes of metastatic lung carcinoids are discouraging. This study aimed to investigate the EGFR mutation using the PNA-mediated clamping method and to provide basic data for using EGFR-TK1 and its clinical implications. Materials and Methods A total of 14 cases that underwent surgery were diagnosed as carcinoid tumors and pathologically classified as TC and AC. The paraffin-embedded tissues were analyzed for EGFR mutations using the PNA-mediated PCR clamping technique. The mutant type was noted in the cases with a△Ct greater than 2.0. Result Of 14 cases, eight were AC and six cases were TC. No known EGFR mutation was detected with a△Ct less than 2.0. Conclusion The EGFR genotype determined using the PNA-mediated PCR clamping method was wild-type in all pulmonary carcinoid tumors. Therefore, the application of EGFR-TK1 is limited in pulmonary carcinoid tumors.

Chronic Obstructive Pulmonary Disease-Related Non-Small-Cell Lung Cancer Exhibits a Low Prevalence of EGFR and ALK Driver Mutations

Lung cancer and chronic obstructive pulmonary disease (COPD) are two major lung diseases. Epidermal growth factor receptor (EGFR) mutations, v-Ki-ras2 Kirsten rat sarcoma (KRAS) mutations and anaplastic lymphoma kinase (ALK) gene rearrangements represent driver mutations that are frequently assessed on initial evaluation of non-small-cell lung cancer (NSCLC). The present study focused on the expression of driver mutations in NSCLC patients presenting with COPD and further evaluated the association between NSCLC and COPD. Data from 501 consecutive patients with histologically proven recurrent or metastatic NSCLC were analyzed retrospectively. The patients underwent spirometry and genotyping of EGFR, ALK, and KRAS in tissue samples. Patient characteristics and expression of driver mutations were compared between the COPD and non-COPD groups. Among 350 patients with spirometric results, 106 (30.3%) were diagnosed with COPD, 108 (30.9%) had EGFR mutations, 31 (8.9%) had KRAS mutations, and 34 (9.7%) showed ALK rearrangements. COPD was independently associated with lower prevalences of EGFR mutations (95% confidence interval [CI], 0.254-0.931, p = 0.029) and ALK rearrangements (95% CI, 0.065-0.600, p = 0.004). The proportions of EGFR mutations and ALK rearrangements decreased as the severity of airflow obstruction increased (p = 0.001). In never smokers, the prevalence of EGFR mutations was significantly lower in the COPD group than in the non-COPD group (12.7% vs. 49.0%, p = 0.002). COPD-related NSCLC patients exhibited low prevalences of EGFR mutations and ALK rearrangements compared with the non-COPD group. Further studies are required regarding the molecular mechanisms underlying lung cancer associated with COPD.

Multiplexed molecular profiling of lung cancer using pleural effusion

INTRODUCTION

Pleural effusion is frequently observed in patients with advanced lung cancer. Although effusion can be obtained less invasively and repeatedly, its use in multiplexed molecular profiling has not been fully investigated.

METHODS

Between July 2011 and April 2013, pleural effusion samples were obtained from patients with lung cancer at Shizuoka Cancer Center. They were analyzed for EGFR, KRAS, BRAF, PIK3CA, NRAS, MEK1, AKT1, PTEN, and HER2 mutations, EGFR, MET, FGFR1, FGFR2, and PIK3CA amplifications, and ALK, ROS1, and RET fusion genes using pyrosequensing and/or capillary electrophoresis, quantitative reverse-transcriptase polymerase chain reaction, and reverse-transcriptase polymerase chain reaction, respectively.

RESULTS

One hundred and two samples from 84 patients were analyzed. Adenocarcinoma was the most common histological subtype (82%). Genetic abnormalities were detected in 42% of patients. The most common abnormality was EGFR mutation (29%), followed by EML4-ALK rearrangement (5%), KRAS mutation, and EGFR amplification (4%, each). Concordance rates between pleural effusion and matched formalin-fixed, paraffin-embedded samples were 88%. Among 11 patients who provided samples at multiple time points, changes in molecular profile over the course of treatment were observed in five patients.

CONCLUSIONS

The use of pleural effusion for multiplexed molecular testing and real-time monitoring in lung cancer was demonstrated.

Limitations in the Use of Serum Epidermal Growth Factor Receptor Mutations as Prognostic Markers for Non-Small-Cell Lung Cancer

OBJECTIVES

In this study, we surveyed patients with advanced non-small-cell lung cancer (NSCLC) who were undergoing tyrosine kinase inhibitor (TKI)-targeted therapy. Our aim was to determine whether epidermal growth factor receptor (EGFR) mutations in serum circulating tumor (ct)DNA are useful prognostic markers for NSCLC. Sujects and Methods: Serum samples were collected from 300 patients with NSCLC that included adenocarcinoma (ADC, n = 155) and squamous cell carcinoma (SCC, n = 145). DNA was extracted from the sera for the nested polymerase chain reaction (PCR) amplification of EGFR exons 18, 19 and 21 mutations. Direct sequencing of the PCR products was carried out in an automated 3730 sequencer.

RESULTS

The EGFR exons 18, 19 and 21 were successfully detected in the serum samples of 300 NSCLC patients. No EGFR mutation was found in the blood samples regardless of the characteristics of gender, age, ADC and SCC status or smoking history.

CONCLUSION

No mutations in EGFR exons 18, 19 or 21 were identified in the serum ctDNA of these advanced-stage NSCLC patients undergoing TKI-targeted therapy. More studies are needed on the use of EGFR mutations in serum ctDNA as guidance for TKI-targeted therapy.

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.

Comparison of PNA clamping and direct sequencing for detecting KRAS mutations in matched tumour tissue, cell block, pleural effusion and serum from patients with malignant pleural effusion

BACKGROUND AND OBJECTIVE

Peptide nucleic acid (PNA)-mediated real-time polymerase chain reaction clamping was recently developed to improve mutation detection sensitivity. Pleural effusion could be a good sample candidate for mutation analysis. To establish if PNA clamping could be used to detect KRAS mutation in particular in pleural effusion, we analysed its diagnostic performance.

METHODS

We studied 57 patients with malignant effusion. KRAS mutation was evaluated in samples of matched tumour tissue, cell block, pleural effusion and serum using PNA clamping and direct sequencing.

RESULTS

The detection rate of KRAS mutation using pleural effusion was 14% for PNA clamping and 10.5% for direct sequencing. The κ coefficient between the two methods was 0.76 (P value < 0.0001), 1.00 (P value < 0.0001) and 0.87 (P value < 0.0001) in pleural effusion, tissue and cell block, respectively. The diagnostic performance of KRAS mutation detection from pleural effusion compared with the results obtained for all samples combined showed that the sensitivity, specificity, positive predictive value and negative predictive value were as follows: 89, 100, 100 and 98%, respectively for PNA clamping; 67, 100, 100 and 94%, respectively for directing sequencing.

CONCLUSIONS

The current study suggests that PNA clamping had a good concordance with direct sequencing for the detection of KRAS mutation in patients with malignant effusion. Furthermore, the good diagnostic performance obtained from pleural effusion samples provides evidence that pleural effusion can be a useful source for detecting KRAS mutation in a clinical setting, in which the collection of tumour tissues is challenging.

Predictive value of a serum-based proteomic test in non-small-cell lung cancer patients treated with epidermal growth factor receptor tyrosine kinase inhibitors: a meta-analysis

OBJECTIVE

Several studies have demonstrated that a serum-based proteomic test (VeriStrat * ) is able to predict the clinical outcome of non-small-cell lung cancer (NSCLC) patients treated with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). However, these studies have limited power to draw a precise conclusion because of their small sample sizes and inconsistent results. Therefore, a meta-analysis was carried out in an attempt to provide more persuasive evidence.

RESEARCH DESIGN AND METHODS

Electronic searches for relevant articles in PubMed, Embase, Medline, and Web of Science published up to May 2013 were conducted. Stata Statistical Software version 12.0 was applied for statistical analysis. The combined hazard ratio (HR) and 95% confidence interval (CI) were estimated using fixed-effects models.

RESULTS

Eleven cohorts involving 706 patients collected from seven studies were subjected to final analysis. This serum-based proteomic test's 'good' status predicted a better clinical outcome with a pooled HR of 0.40 (95% CI 0.32 to 0.49; p < 0.001) for overall survival (OS), and 0.49 (95% CI 0.39 to 0.60; p < 0.001) for progression-free survival (PFS). There was no significant heterogeneity, but a slight publication bias in this study.

CONCLUSIONS

Our meta-analysis demonstrated that this serum-based proteomic test has a predictive value for NSCLC patients treated with EGFR-TKIs. Future data are needed to validate and update our results.

Diagnostic value of circulating free DNA for the detection of EGFR mutation status in NSCLC: a systematic review and meta-analysis

Epidermal growth factor receptor (EGFR) mutation is a reliable and sensitive biomarker for EGFR-TKI therapy in non-small-cell lung cancer (NSCLC). However, detection of EGFR mutation in tissues has obvious limitations. Circulating free DNA (cfDNA) has been reported as an alternative approach for the detection of EGFR mutations. This systematic review and meta-analysis was designed to assess the diagnostic performance of cfDNA, compared with tissues. True-positive (TP), false-positive (FP), false-negative (FN), and true-negative (TN) values were extracted or calculated for each study. Pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were calculated. A summary receiver operating characteristic curve (SROC) and area under curve (AUC) were used to evaluate the overall diagnostic performance. 20 eligible studies involving 2012 cases were included in this meta-analysis. The pooled sensitivity, specificity, PLR, NLR, andDORwere 0.674 (95%CI: 0.517–0.800), 0.935 (95%CI: 0.888–0.963), 10.307 (95%CI: 6.167–17.227), 0.348 (95%CI: 0.226–0.537), and 29.582 (95%CI: 4.582–60.012), respectively. The AUC was 0.93 (95% CI: 0.90–0.95). The meta-analysis suggests that detection of EGFR mutation by cfDNA is of adequate diagnostic accuracy and cfDNA analysis could be a promising screening test for NSCLC.

Lung cancer coexisting with ipsilateral pleural effusion

SUMMARY 

Invasion beyond the elastic layer of the visceral pleura and/or diffuse pleural metastatic spread affects negatively survival in lung cancer. Presence of pleural effusion is also associated with poor prognosis, and image techniques can be of great help for diagnosis. When pleural fluid cytology is negative, thoracoscopy is advisable before attempting tumor resection, in order to detect unsuspected pleural metastases. If widespread pleural malignancy is confirmed, chemical pleurodesis using graded talc (with particles larger than 20 µm in diameter) is the best option, unless the lung is unable to re-expand. In this case, or when a previous pleurodesis has failed, or there is a short life expectancy, placement of a indwelling pleural catheter is the treatment of choice.

Simultaneous diagnostic platform of genotyping EGFR, KRAS, and ALK in 510 Korean patients with non-small-cell lung cancer highlights significantly higher ALK rearrangement rate in advanced stage

BACKGROUND

Simultaneous genotyping has advantages in turnaround time and detecting the real mutational prevalence in unresectable non-small-cell lung cancer (NSCLC), a group not previously genetically characterized.

METHODS

We developed simultaneous panel of screening EGFR and KRAS mutations by direct sequencing or PNA clamping, and ALK rearrangement by fluorescent in situ hybridization (FISH) in multicenter manner.

RESULTS

Of 510 NSCLC Korean patients, simultaneous genotyping identified mutations of EGFR (29.0%) and KRAS (8.6%) and rearrangement of ALK (9.2%). Seven patients had overlaps in mutations. Although several well-known associations between genotypes and clinical characteristics were identified, we found no relationship between ALK rearrangement and sex or smoking history. Unlike the other genotype mutations, ALK rearrangement was associated with advanced disease. Among the ALK-negative group, patients with 10-15% of ALK FISH split shared characteristics, such as younger age and advanced stage disease, more with the ALK-positive group (>15% ALK FISH split) than <10% ALK FISH split group.

CONCLUSIONS

Simultaneous panel genotyping revealed more prevalent ALK rearrangements than reported in previous studies and their strong association with advanced stage irrespective of sex or smoking history. ALK rearrangement seems to be a marker for aggressive tumor biology and should be assessed in advanced disease.

Genetic alterations defining NSCLC subtypes and their therapeutic implications

Lung cancer is the leading cause of cancer death worldwide, accounting for more deaths than breast, prostate and colon cancer combined. While treatment decisions are determined primarily by stage, therapeutically non small cell lung cancer (NSCLC) has traditionally been treated as a single disease. However, recent findings have led to the recognition of histology and molecular subtypes as important determinants in treatment selection. Identifying the genetic differences that define these molecular and histological subtypes has the potential to impact treatment and as such is currently the focus of much research. Microarray and genomic sequencing efforts have provided unparalleled insight into the genomes of lung cancer subtypes, specifically adenocarcinoma (AC) and squamous cell carcinoma (SqCC), revealing subtype specific genomic alterations and molecular subtypes as well as differences in cell signaling pathways. In this review, we discuss the recurrent genomic alterations characteristic of AC and SqCC (including molecular subtypes), their therapeutic implications and emerging clinical practices aimed at tailoring treatments based on a tumor's molecular alterations with the hope of improving patient response and survival.