A Comparison of Cytology and Fluorescence in Situ Hybridization for the Detection of Lung Cancer in Bronchoscopic Specimens

Advances in lung cancer screening and early detection

Lung cancer is associated with a heavy cancer-related burden in terms of patients' physical and mental health worldwide. Two randomized controlled trials, the US-National Lung Screening Trial (NLST) and Nederlands-Leuvens Longkanker Screenings Onderzoek (NELSON), indicated that low-dose CT (LDCT) screening results in a statistically significant decrease in mortality in patients with lung cancer, LDCT has become the standard approach for lung cancer screening. However, many issues in lung cancer screening remain unresolved, such as the screening criteria, high false-positive rate, and radiation exposure. This review first summarizes recent studies on lung cancer screening from the US, Europe, and Asia, and discusses risk-based selection for screening and the related issues. Second, an overview of novel techniques for the differential diagnosis of pulmonary nodules, including artificial intelligence and molecular biomarker-based screening, is presented. Third, current explorations of strategies for suspected malignancy are summarized. Overall, this review aims to help clinicians understand recent progress in lung cancer screening and alleviate the burden of lung cancer.

Evaluation of the diagnostic accuracy of bronchial brushing cytology in lung cancer: A meta-analysis

BACKGROUND

Flexible bronchoscopy is commonly used to examine patients suspected to have lung cancer. Bronchial brushing is one of the cytological technologies for lung specimens obtained through a bronchoscope. However, the accuracy of bronchial brushing cytology (BBC) for lung cancer diagnosis is still inconclusive. The aim of this study was to evaluate the diagnostic accuracy of BBC.

METHODS

A literature search was conducted with PubMed, Embase, the Cochrane Library, Web of Science, Biomed Central, Clinical Key, and ClinicalTrials.gov. Studies that assessed the efficacy of BBC in detecting lung cancer were included. Articles that estimated the accuracy on a per-patient basis were included. Review articles, case reports, and research that provided insufficient data to construct a 2 × 2 table were excluded. Both prospective trials and retrospective studies were included. English language studies were reviewed. Data synthesis was performed with a random-effects model.

RESULTS

Seventeen studies with 2538 patients were included in the study. The meta-analysis for BBC generated a pooled sensitivity of 0.67 (95% confidence interval [CI], 0.65-0.70) and a pooled specificity of 0.91 (95% CI, 0.89-0.93). The pooled diagnostic odds ratio for BBC was 24.55 (95% CI, 12.39-48.66). The subgroup analysis for studies using liquid-based cytology (LBC) generated a pooled sensitivity of 0.68 and a pooled specificity of 0.92. The pooled diagnostic odds ratio of studies using LBC was 114.18.

CONCLUSIONS

These findings indicate that BBC is a discriminative diagnostic approach with moderate sensitivity and high specificity for diagnosing peripheral pulmonary lesions. BBC using LBC has higher diagnostic performance.

Testing EGFR with Idylla on Cytological Specimens of Lung Cancer: A Review

The current standard of care for advanced non-small-cell lung cancer is based on detecting actionable mutations that can benefit from targeted therapy. Comprehensive genetic tests can have long turn-around times, and because EGFR mutations are the most prevalent actionable mutation, a quick detection would enable a prompt initiation of targeted therapy. Furthermore, the scarcity of diagnostic material means that sometimes only cytologic material is available. The Idylla™ EGFR assay is a real-time PCR–based method able to detect 51 EGFR mutations in 2.5 h. Idylla is validated for use only on FFPE sections, but some researchers described their experiences with cytological material. We reviewed the relevant literature, finding four articles describing 471 cases and many types of cytological input material: smears, cell-block sections, suspensions, and extracted DNA. The sensitivity, specificity, and limit of detection appear comparable to those obtained with histological input material, with one exception: the usage of scraped stained smears as input may reduce the accuracy of the test. In conclusion, usage of cytological material as input to the Idylla EGFR test is possible. A workflow where common mutations are tested first and fast, leaving rarer mutations for subsequent comprehensive profiling, seems the most effective approach.

Molecular biomarkers in early stage lung cancer

Low dose computed tomography (LDCT) screening, together with the recent advances in targeted and immunotherapies, have shown to improve non-small cell lung cancer (NSCLC) survival. Furthermore, screening has increased the number of early stage-detected tumors, allowing for surgical resection and multimodality treatments when needed. The need for improved sensitivity and specificity of NSCLC screening has led to increased interest in combining clinical and radiological data with molecular data. The development of biomarkers is poised to refine inclusion criteria for LDCT screening programs. Biomarkers may also be useful to better characterize the risk of indeterminate nodules found in the course of screening or to refine prognosis and help in the management of screening detected tumors. The clinical implications of these biomarkers are still being investigated and whether or not biomarkers will be included in further decision-making algorithms in the context of screening and early lung cancer management still needs to be determined. However, it seems clear that there is much room for improvement even in early stage lung cancer disease-free survival (DFS) rates; thus, biomarkers may be the key to refine risk-stratification and treatment of these patients. Clinicians’ capacity to register, integrate, and analyze all the available data in both high risk individuals and early stage NSCLC patients will lead to a better understanding of the disease’s mechanisms, and will have a direct impact in diagnosis, treatment, and follow up of these patients. In this review, we aim to summarize all the available data regarding the role of biomarkers in LDCT screening and early stage NSCLC from a multidisciplinary perspective. We have highlighted clinical implications, the need to combine risk stratification, clinical data, radiomics, molecular information and artificial intelligence in order to improve clinical decision-making, especially regarding early diagnostics and adjuvant therapy. We also discuss current and future perspectives for biomarker implementation in routine clinical practice.

Biomarkers in Lung Cancer Screening: Achievements, Promises, and Challenges

The present review is an update of the research and development efforts regarding the use of molecular biomarkers in the lung cancer screening setting. The two main unmet clinical needs, namely, the refinement of risk to improve the selection of individuals undergoing screening and the characterization of undetermined nodules found during the computed tomography-based screening process are the object of the biomarkers described in the present review. We first propose some principles to optimize lung cancer biomarker discovery projects. Then, we summarize the discovery and developmental status of currently promising molecular candidates, such as autoantibodies, complement fragments, microRNAs, circulating tumor DNA, DNA methylation, blood protein profiling, or RNA airway or nasal signatures. We also mention other emerging biomarkers or new technologies to follow, such as exhaled breath biomarkers, metabolomics, sputum cell imaging, genetic predisposition studies, and the integration of next-generation sequencing into study of circulating DNA. We also underline the importance of integrating different molecular technologies together with imaging, radiomics, and artificial intelligence. We list a number of completed, ongoing, or planned trials to show the clinical utility of molecular biomarkers. Finally, we comment on future research challenges in the field of biomarkers in the context of lung cancer screening and propose a design of a trial to test the clinical utility of one or several candidate biomarkers.

The utility of bronchial brushings in the modern era of flexible bronchoscopy

INTRODUCTION

Bronchoscopic procedures allow for the procurement of cellular material for diagnosis, molecular studies, and staging. Procurement modalities include bronchoalveolar lavage (BAL), bronchial washing (BW), transbronchial ultrasound-guided needle aspiration (TBNA), transbronchial biopsy (TBBX), endobronchial biopsy (EB), and bronchoscopic brushing (BB). These specimens, taken concurrently, often circumvent the need for an open biopsy, and allow for more appropriate and efficient patient management. Although BB is a well-established method for obtaining cytologic material, it often introduces artifacts and may contain abundant material such as benign and/or metaplastic bronchial epithelium, both of which may result in atypical or false-positive diagnoses. We examined the utility of BB specimens at our institution in recent years.

METHODS

210 BB specimens were identified at our institution over a 2-year period, allowing for at least a 2-year follow-up period. The diagnoses were compiled and compared against results from simultaneously obtained BAL, BW, TBNA, TBBX, and EB specimens, as well as any follow-up during the subsequent 2- to 4-year period.

RESULTS

BB specimens were diagnosed as malignant (n = 44), benign (130), indeterminate (30), and non-diagnostic (6). There were no false-positive diagnoses. There were 6 instances in which malignancy was not definitively diagnosed on a non-BB specimen but definitively diagnosed on BB.

CONCLUSION

BB specimens rarely provide the only diagnostic material during a bronchoscopic procedure, though they possess excellent specificity for malignancy. Indeterminate diagnoses have a positive predictive value of approximately 73%.

Analysis of Chromosome 3, 7 and 8 Centromeric Regions in Bronchial Lavage Specimens by FISH

OBJECTIVES

Multiple genetic changes are observed in malignant tumors but are rare or absent in benign conditions. Aneuploidy is the most common feature of solid tumors including lung cancer and diagnosis of malignant tumors is possible through detection of aneuploidy. The aim of this study was to investigate chromosomal abnormalities in cells from non-small cell lung cancer patients obtained bronchoscopically and to evaluate the suitability of fluorescence in situ hybridization (FISH).

MATERIAL AND METHODS

Bronchial lavage samples of 17 non-small cell lung cancer (NSCLC) patients were evaluated with four-color FISH using deoxyribonucleic acid (DNA) probes specific for the centromere regions of chromosomes 3, 7 and 8. tested specimens were first hybridized with probes, then visualized under fluorescence microscobe and captured with device's camera.

RESULTS

High number of aneuploidic cells were detected in all the samples. Increased or decreased abnormal copies or chromosomes 3, 7 and 8 were obserced in all the 17 patients. Aneuploidy of chromosome 3 (21.35%) was higher than those of chromosome 7 (9.06%) and chromosome 8 (15.47%). Moreover, our results were significant for monosomy and trisomy of chromosome 3, trisomy of chromosome 7, nullisomy, monosomy and trisomy of, chromosome 8 (p< 0.05).

CONCLUSION

It has been observed that FISH is a useful technique for detection of aneuploidy in bronchial lavage samples obtained by bronchoscopy. Interphase cells were evaluated without cell culturing with this method and high number of tumor cells were enumerated rapidly. Our study has demonstrated that, FISH technique may be used successfully in detection of chromosome number abnormalities in NSCLC patients and may facilitate evaluation of genetic abnormalities.

Carbonic anhydrase 1 is a promising biomarker for early detection of non-small cell lung cancer

This study aimed to identify candidate biomarkers associated with stage I non-small cell lung cancer (NSCLC). Sera from three groups, a lung cancer group (n = 11), benign control group (n = 12), and normal control group (n = 10), were collected and pooled. Protein expression profiles were analyzed by a combination of two-dimensional electrophoresis (2DE) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). These methods were used to separate, screen, and identify proteins that were differentially expressed between stage I NSCLC and controls. Differentially expressed proteins were validated by both Western blot and ELISA in an expanded sample size (22, 18, and 18 in three groups, respectively). MALDI-MS identified 12 differentially expressed proteins in the lung cancer group compared to the two control groups. Expression of carbonic anhydrase 1 (CA1) was validated by Western blot. CA1 was significantly elevated in the lung cancer group compared to controls. ELISA results confirmed that CA1 in the lung cancer group (3.18 ± 1.27 ng/mL, n = 22) was highly expressed in stage I NSCLC patients compared to those in the benign control group (2.21 ± 0.71 ng/mL, n = 18) and the normal control group (2.04 ± 0.63 ng/mL, n = 18) (P = 0.001). In conclusion, we provide evidence that CA1 is highly expressed in the sera of stage I NSCLC patients. Additionally, CA1 might serve as a novel biomarker for early detection of NSCLC.

Diagnostic accuracy of bronchial brush cytology and the added value of immunohistochemistry and fluorescence in situ hybridization of pulmonary neuroendocrine tumors

Background:

Bronchial brush (BB) cytology carries low sensitivity for detecting neuroendocrine carcinomas (NECs), including typical carcinoid (TC) tumors of the lung. We aimed to investigate the detection of neuroendocrine tumors including TC through BB routine cytology cell block (CB), immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH).

Materials and Methods:

A SNOMED search showed 187 lung biopsy or resection specimens from 2008 through 2011 containing neuroendocrine or carcinoid in the diagnosis. Residual BB specimens retained in PreservCyt were used to prepare a ThinPrep slide for FISH analysis. CBs were stained with H and E and IHC for chromogranin and synaptophysin.

Results:

Of the 187 cases, 16 had residual BB material available within 1 year of diagnosis and were used in CB preparation for IHC and FISH slides. Cytologic evaluation determined 1 case positive for malignancy (small cell lung carcinoma [SCLC]), 1 suspicious for adenocarcinoma, and 14 negative for malignancy. On the basis of histologic diagnosis, FISH was performed. SCLC showed polysomy (86% abnormal cells); 2 TC tumors showed a gain of 7p12 (15% abnormal cells) and a gain of 5q15 (72% abnormal cells), respectively. Two cases had CBs with positive immunoreactivity for chromogranin and synaptophysin. The sensitivity for detection of NEC was 18.8%, 15.4%, and 25% for cytologic evaluation, CB, and FISH, respectively.

Conclusion:

Neuroendocrine tumors, including TC are difficult to detect with BB cytologic evaluation, most likely because tumor cells lack in the specimen. Assessment of further studies is needed to explore the role of cytology and ancillary methods for detection of these tumors.

microRNA detection in feces, sputum, pleural effusion and urine: novel tools for cancer screening (Review)

microRNAs (miRNAs) are short non-coding RNA sequences that play important roles in the regulation of gene expression. They have significant regulatory functions in basic cellular processes, including differentiation, proliferation and apoptosis. miRNAs are differentially expressed in tumors, compared with normal tissues. Importantly, miRNAs are also stable and abundantly present in body fluids and feces. The high reproducibility, sensitivity and specificity of miRNAs in body fluids and feces enable miRNAs to be used as potential molecular markers for cancer screening. An increasingly large number of research studies have reported the role of miRNAs in this field. In the present review, we focused mainly on the application of detecting miRNAs in stool, sputum, pleural effusion and urine, to detect colon, lung and urological cancers, highlighting the role of miRNAs in early diagnosis and prognosis.

Molecular biology of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

Based on recent bench and clinical research, the treatment of lung cancer has been refined, with treatments allocated according to histology and specific molecular features. For example, targeting mutations such as epidermal growth factor receptor (EGFR) with tyrosine kinase inhibitors has been particularly successful as a treatment modality, demonstrating response rates in selected patients with adenocarcinoma tumors harboring EGFR mutations that are significantly higher than those for conventional chemotherapy. However, the development of new targeted therapies is, in part, highly dependent on an improved understanding of the molecular underpinnings of tumor initiation and progression, knowledge of the role of molecular aberrations in disease progression, and the development of highly reproducible platforms for high-throughput biomarker discovery and testing. In this article, we review clinically relevant research directed toward understanding the biology of lung cancer. The clinical purposes of this research are (1) to identify susceptibility variants and field molecular alterations that will promote the early detection of tumors and (2) to identify tumor molecular alterations that serve as therapeutic targets, prognostic biomarkers, or predictors of tumor response. We focus on research developments in the understanding of lung cancer somatic DNA mutations, chromosomal aberrations, epigenetics, and the tumor microenvironment, and how they can advance diagnostics and therapeutics.

Detection of lung cancer in bronchial brushing specimens by FISH

Bronchial brushing cytology specimens collected during flexible bronchoscopy are an important part of the diagnostic workup of patients with indeterminate pulmonary nodules. Unfortunately, false-negative diagnoses are not uncommon when sampling peripheral nodules, especially small nodules <2 cm in diameter. A number of studies have evaluated different FISH probe sets to increase the detection rate of lung cancer on bronchial brushings and washings. Most studies have shown that FISH with routine cytology increases the sensitivity of lung cancer detection over routine cytology alone, while maintaining high specificity. In this article, the authors review a recently published three-probe FISH assay for the detection of lung cancer in bronchial brushing specimens.

Detection of lung cancer using multiple genetic markers--a systematic review

Lung cancer is the leading cause of cancer deaths worldwide, and has one of the lowest survival rates of any solid tumor. In recent years, several attempts have been conducted to improve an early or accelerated diagnosis due to better overall prognosis after therapy. The aim of this study was evaluating the use of genetic markers for diagnosis of lung cancer. This study was conducted in accordance to Transparent Reporting of Systematic Reviews and Meta-Analyses. Three Internet sources were used to search: MEDLINE-PubMed, EMBASE, and LILACS. The databases were searched for studies conducted in the period up to and including May 10, 2011. The following inclusion criteria were applied: lung cancer studies, and the use of genetic markers for diagnosis. Studies using animal models, review articles, meta-analyses, abstracts, conference proceedings, editorials/letters, case reports, incorrect study population, inadequate data, and cytology was not obtained, were excluded. A total of 1,901 abstracts/citations were identified for preliminary review. From 24 final selected studies, 17 referred to chromosomal markers diagnosis, eight to genes as marker, and one to both subjects. Fluorescence in situ hybridization (FISH) was applied in all studies. Despite the limitations of this study, application of genetic markers to lung cancer diagnosis seems to have prognosis value irrespective of detection methodology used. FISH was the main technique applied to diagnose genetics alterations and revealed a high specificity, although some authors reported low sensitivity.

A potential probe set of fluorescence in situ hybridization for detection of lung cancer in bronchial brushing specimens

PURPOSE

The study aims to find candidate probes of fluorescence in situ hybridization (FISH) for detection of lung cancer with bronchial brushings and to evaluate whether the accuracy of diagnosing lung cancer by cytological deviant and genetic abnormalities is greater than that of cytology alone.

METHODS

Centromeric enumeration probes (CEPs) for chromosomes 2, 3, 6, 7, 8, 9, 11, 12, and 17 were analyzed using FISH in 74 surgical resection tissues, 32 operative margin tissues without tumor involvement of lung cancer, and 174 bronchial brushings.

RESULTS

The aneuploidy rates of the tested probes were 61.7, 89.1, 80.0, 92.7, 65.0, 70.4, 66.7, 71.8, 68.9 % in tumor tissues, and 29.3, 58.9, 33.3, 69.6, 67.0, 40.3, 38.0, 49.3, 35.1 % in bronchial brushings. The combination of cytology and FISH using the three-probe set for chromosomes 3+7+8 significantly improved the sensitivity of bronchial brushing examination for lung cancer detection (P = 0.00003), especially squamous cell carcinoma (SCC), which increased from 78.0 to 98.2 %. The specificity of the 3+7+8 probe set was 94.6 %. Moreover, a high aneuploidy rate of the probe set in bronchial brushings was detected more often in SCCs (P = 0.029) and late-stage non-small-cell lung cancer (NSCLC) (P = 0.044). Kaplan-Meier curves indicated that adenocarcinoma (ADC) patients with high aneuploidy rate of CEP3 in tissue samples exhibited poorer overall survival (P = 0.016).

CONCLUSIONS

FISH performed on cytology preparations is useful for confirmation of cancer diagnosis. The three-probe set, 3+7+8, has potential value for the detection of SCCs in bronchial brushings.

The state of molecular biomarkers for the early detection of lung cancer

Using biomarkers to select the most at-risk population, to detect the disease while measurable and yet not clinically apparent has been the goal of many investigations. Recent advances in molecular strategies and analytic platforms, including genomics, epigenomics, proteomics, and metabolomics, have identified increasing numbers of potential biomarkers in the blood, urine, exhaled breath condensate, bronchial specimens, saliva, and sputum, but none have yet moved to the clinical setting. Therefore, there is a recognized gap between the promise and the product delivery in the cancer biomarker field. In this review, we define clinical contexts where risk and diagnostic biomarkers may have use in the management of lung cancer, identify the most relevant candidate biomarkers of early detection, provide their state of development, and finally discuss critical aspects of study design in molecular biomarkers for early detection of lung cancer.

Update on biomarkers for the detection of lung cancer

Patients at risk for lung cancer may have subclinical disease for years before presentation. The diagnosis of this disease is primarily based on symptoms, and detection often occurs after curative intervention is no longer possible. At present, no lung cancer early-detection biomarker is clinically available. This study reviews the most recent advances in early detection and molecular diagnostic biomarkers for the detection of lung cancer. This review includes an overview of the various biological specimens and matrices in which these biomarkers could be analyzed, as well as the diverse strategies and approaches for identifying new biomarkers that are currently being explored. Several novel and attractive biomarker candidates for the early detection of lung cancer exist. A remarkable shift is taking place from research based on single markers to analyzing signatures that are more complex in order to take advantage of new high-throughput technologies. However, it is still necessary to validate the most promising markers and the standardization of procedures that will lead to specific clinical applications.

Equivocal cytology in lung cancer diagnosis: improvement of diagnostic accuracy using adjuvant multicolor FISH, DNA-image cytometry, and quantitative promoter hypermethylation analysis

BACKGROUND

Sometimes, cytological lung cancer diagnosis is challenging because equivocal diagnoses are common. To enhance diagnostic accuracy, fluorescent in situ hybridization (FISH), DNA-image cytometry, and quantitative promoter hypermethylation analysis have been proposed as adjuncts.

METHODS

Bronchial washings and/or brushings or transbronchial fine-needle aspiration biopsies were prospectively collected from patients who were clinically suspected of having lung carcinoma. After routine cytological diagnosis, 70 consecutive specimens, each cytologically diagnosed as negative, equivocal, or positive for cancer cells, were investigated with adjuvant methods. Suspicious areas on the smears were restained with the LAVysion multicolor FISH probe set (Abbott Molecular, Des Plaines, Illinois) or according to the Feulgen Staining Method for DNA-image cytometry analysis. DNA was extracted from residual liquid material, and frequencies of aberrant methylation of APC, p16(INK4A) , and RASSF1A gene promoters were determined with quantitative methylation-specific polymerase chain reaction (QMSP) after bisulfite conversion. Clinical and histological follow-up according to a reference standard, defined in advance, were available for 198 of 210 patients.

RESULTS

In the whole cohort, cytology, FISH, DNA-image cytometry, and QMSP achieved sensitivities of 83.7%, 78%, 79%, and 49.6%, respectively (specificities of 69.8%, 98.2%, 98.2%, and 98.4%, respectively). Subsequent to cytologically equivocal diagnoses, FISH, DNA-image cytometry, and QMSP definitely identified malignancy in 79%, 83%, and 49%, respectively. With QMSP, 4 of 22 cancer patients with cytologically negative diagnoses were correctly identified.

CONCLUSIONS

Thus, adjuvant FISH or DNA-image cytometry in cytologically equivocal diagnoses improves diagnostic accuracy at comparable rates. Adjuvant QMSP in cytologically negative cases with persistent suspicion of lung cancer would enhance sensitivity.

[Non-surgical biopsy in lung cancer: a paradigm shift]

Histological subgroups of non-small cell lung cancer have different prognosis and they require different therapeutic approaches. Accordingly, there is a clinical need in this field to supplement conventional pathological diagnostics with protein and genetic biomarkers that can help to recognize patients responsive to these therapies. Methods for subgroup classification and target identification were developed using surgical samples (surgical lung tumor specimens are available only in 20% of all lung cancer cases). The majority of lung cancer patients, however, have tumors that are irresectable at the time of diagnosis. Therefore, their diagnosis is usually based on bronchoscopically removed tissue or needle biopsy samples analyzed mainly by cytology. Because of the growing need for immunohistochemistry and molecular pathology in lung cancer diagnosis, emphasis should be given to diagnostic bronchoscopic procedures providing tissue samples. Combination of the different biopsy techniques (histology, cytology, bronchial brush, BAL, TBNA etc.), embedding the cells (preparing cell blocks) and, moreover, the availability of immunohistochemical and molecular pathological facilities are all required to set up the proper diagnosis and therapeutic strategy in human lung cancer. Strausz J, Tímár J. Non-surgical biopsy in lung cancer: a paradigm shift.

Fluorescent in situ hybridization (FISH) in the differential diagnosis of ground-glass opacities in the lung

Computed tomographic (CT) screening for lung cancer has increased the detection rate of nodules manifesting as ground-glass opacities (GGOs). The natural history of this new entity it is not well known nor is the factors that influence the growth, progression and malignant potential. This genetic study was performed in order to identify molecular markers with possible diagnostic and prognostic significance to differentiate lesions with malignant or benign profiles. Ten pure GGO fresh samples and 5 specimens of normal lung tissue were cytogenetically investigated using a direct method and short-term cultures, and molecular analysis was performed using the 4-target FISH LAVysion kit for the detection of non-small cell lung cancer (NSCLC). Interestingly, all the karyotypes turned out to be normal both with the direct method and cultured cells, while in 3 out of 10 GGOs FISH analysis was abnormal for all the targets and in 2 cases only c-MYC amplification was observed. Karyotypes and FISH performed on the normal tissue samples gave normal results. Two of three FISH positive patients died, one had a relapse of the disease and at the last follow-up showed lung and bone metastases. Despite the small sample due to the rarity of pure GGOs, these preliminary results indicate that interphase FISH analyses are more informative than metaphase studies and might contribute clinically relevant information about the nature of these lesions.

Genetically abnormal circulating cells in lung cancer patients: an antigen-independent fluorescence in situ hybridization-based case-control study

PURPOSE

We performed a study to determine if a fluorescence in situ hybridization (FISH)-based assay using isolated peripheral blood mononuclear cells (PBMCs) with DNA probes targeting specific sites on chromosomes known to have abnormalities in non-small cell lung cancer (NSCLC) cases could detect circulating genetically abnormal cells (CACs).

EXPERIMENTAL DESIGN

We evaluated 59 NSCLC cases with stage I through IV disease and 24 controls. PBMCs and matched tumors were hybridized with 2 two-color [3p22.1/CEP3 and 10q22.3 (SP-A)/CEP10) and 2 four-color [CEP3, CEP7, CEP17, and 9p21.3 (URO); and EGFR, c-MYC, 6p11-q11, and 5p15.2 (LAV)] FISH probes. Percentages of cytogenetically abnormal cells (CACs) in peripheral blood and in matched tumor specimens were quantified by using an automated fluorescent scanner. Numbers of CACs were calculated based on the percentage of CACs (defined as PBMCs with genetic abnormalities) per milliliter of blood and expressed per microliter of blood.

RESULTS

Patients with NSCLC had significantly higher numbers of CACs than controls. Mean number of CACs ranged from 7.23 +/- 1.32/microL for deletions of 10q22.3/CEP10 to 45.52 +/- 7.49/microL for deletions of 3p22.1/CEP3. Numbers of CACs with deletions of 3p22.1, 10q22.3, and 9p21.3, and gains of URO, increased significantly from early to advanced stage of disease.

CONCLUSIONS

We have developed a sensitive and quantitative antigen-independent FISH-based test for detecting CACs in peripheral blood of patients with NSCLC, which showed a significant correlation with the presence of cancer. If this pilot study can be validated in a larger study, CACs may have a role in the management of patients with NSCLC.

The relationship between the presence of chromosomal instability and prognosis of squamous cell carcinoma of the lung: fluorescence in situ hybridization analysis of paraffin-embedded tissue from 47 Korean patients

To evaluate the prognostic importance of chromosomal instability (CIN) in squamous cell carcinoma (SCC) of the lung, the relationship between CIN detected by fluorescence in situ hybridization (FISH) and survival in SCC patients was examined. Forty-seven surgical specimens of lung SCC were analyzed. To identify tumors with CIN, p16 and multi-target DNA FISH assays for c-myc, chromosome 6, EGFR, and chromosome 5 (LAVysion, Vysis) were performed on nuclei extracted from paraffin-embedded tumor tissues. Survival rates were compared in terms of age, T factor, N factor, CIN, and smoking status. A sample was defined as CIN-positive if at least four of the five chromosomes were positive. Among the 47 specimens, 9 (19%) were CIN-positive. The overall survival rate was 66%. Overall survival rates were estimated as 33.3% for CIN-positive patients and 76.7% for CIN-negative patients (Hazard ratio 3.47; 95% Confidence interval, 1.25-9.67; P=0.017). In multivariate analysis, the presence of CIN was a predictive factor for survival. CIN-positive based on FISH can be prognostic factor of lung SCC.

PCR-quality DNA isolation from human bronchial aspirates and buccal and eyelid swabs by a simple procedure based on alkaline lysis

There are only a few systematic reports about DNA extraction from routine diagnostic cytological specimens. An inevitable drawback of such techniques is increased spending of time and funds required for obligatory DNA purification. To implement a simple protocol for human DNA isolation from cytological specimens related to lung cancer, bronchial aspirates together with samples collected by swabbing of the inner cheek and eyelid were used. By combining alkaline and temperature lyses it was possible to isolate DNA solution ready for PCR in less than an hour. Testing the method used for amplification of sex chromatin gene fragments showed that it is highly efficient. The presented protocol preserves high-quality DNA that is suitable for PCR-based assays.

Recurrent genomic gains in preinvasive lesions as a biomarker of risk for lung cancer

Lung carcinoma development is accompanied by field changes that may have diagnostic significance. We have previously shown the importance of chromosomal aneusomy in lung cancer progression. Here, we tested whether genomic gains in six specific loci, TP63 on 3q28, EGFR on 7p12, MYC on 8q24, 5p15.2, and centromeric regions for chromosomes 3 (CEP3) and 6 (CEP6), may provide further value in the prediction of lung cancer. Bronchial biopsy specimens were obtained by LIFE bronchoscopy from 70 subjects (27 with prevalent lung cancers and 43 individuals without lung cancer). Twenty six biopsies were read as moderate dysplasia, 21 as severe dysplasia and 23 as carcinoma in situ (CIS). Four-micron paraffin sections were submitted to a 4-target FISH assay (LAVysion, Abbott Molecular) and reprobed for TP63 and CEP 3 sequences. Spot counts were obtained in 30-50 nuclei per specimen for each probe. Increased gene copy number in 4 of the 6 probes was associated with increased risk of being diagnosed with lung cancer both in unadjusted analyses (odds ratio = 11, p<0.05) and adjusted for histology grade (odds ratio = 17, p<0.05). The most informative 4 probes were TP63, MYC, CEP3 and CEP6. The combination of these 4 probes offered a sensitivity of 82% for lung cancer and a specificity of 58%. These results indicate that specific cytogenetic alterations present in preinvasive lung lesions are closely associated with the diagnosis of lung cancer and may therefore have value in assessing lung cancer risk.

Genomic profiles associated with early micrometastasis in lung cancer: relevance of 4q deletion

PURPOSE

Bone marrow is a common homing organ for early disseminated tumor cells (DTC) and their presence can predict the subsequent occurrence of overt metastasis and survival in lung cancer. It is still unclear whether the shedding of DTC from the primary tumor is a random process or a selective release driven by a specific genomic pattern.

EXPERIMENTAL DESIGN

DTCs were identified in bone marrow from lung cancer patients by an immunocytochemical cytokeratin assay. Genomic aberrations and expression profiles of the respective primary tumors were assessed by microarrays and fluorescence in situ hybridization analyses. The most significant results were validated on an independent set of primary lung tumors and brain metastases.

RESULTS

Combination of DNA copy number profiles (array comparative genomic hybridization) with gene expression profiles identified five chromosomal regions differentiating bone marrow-negative from bone marrow-positive patients (4q12-q32, 10p12-p11, 10q21-q22, 17q21, and 20q11-q13). Copy number changes of 4q12-q32 were the most prominent finding, containing the highest number of differentially expressed genes irrespective of chromosomal size (P=0.018). Fluorescence in situ hybridization analyses on further primary lung tumor samples confirmed the association between loss of 4q and bone marrow-positive status. In bone marrow-positive patients, 4q was frequently lost (37% versus 7%), whereas gains could be commonly found among bone marrow-negative patients (7% versus 17%). The same loss was also found to be common in brain metastases from both small and non-small cell lung cancer patients (39%).

CONCLUSIONS

Thus, our data indicate, for the first time, that early hematogenous dissemination of tumor cells might be driven by a specific pattern of genomic changes.

3p22.1 and 10q22.3 deletions detected by fluorescence in situ hybridization (FISH): a potential new tool for early detection of non-small cell lung Cancer (NSCLC)

BACKGROUND

Our objective was to study the feasibility of detecting chromosomal deletions at 3p22.1 and 10q22.3 by fluorescent in situ hybridization (FISH) and to examine their distribution in different areas of the airway in patients with non-small cell lung cancer.

METHODS

Brush biopsies from the mainstem bronchus on the normal side contralateral to the tumor (NBB) and mainstem bronchus on the tumor side (TBB) were obtained from 122 patients who underwent surgical resection. Touch preparations from the tumor (TTP), normal lung parenchyma, and bronchi adjacent to the tumor were also obtained. Two FISH assays using probes complementary to 3p22.1 and 10q22.3 were used to detect deletions.

RESULTS

NBB showed a relatively low deletion rate of 3p22.1 and 10q22.3 compared with TTP (p < 0.0001). TBB showed a significantly higher rate of deletions compared with NBB but lower than TTP from the tumor (p < 0.05) for both 3p22.1 and 10q22.3. A significantly higher deletion rate was seen at TTP compared with normal lung parenchyma at both the 3p22.1 and 10 q22.3 (p < 0.0001). Correlations were seen between the deletion rates of TTP and TBB at 3p22.1 (rho = 0.61, p < 0.0001) and between TTP and bronchi adjacent to the tumor at 10q22.3 (rho = 0.64, p < 0.0001).

CONCLUSION

Deletions of the 3p22.1 and 10q22.3 regions can be reliably detected by FISH. As one progresses from the contralateral normal bronchus to the bronchus on the side of tumor and the tumor itself, the percentage of chromosomal deletions increases in a statistically significant fashion. This suggests that, FISH analysis of bronchoscopic brushes may be useful for identifying patients at high risk for developing non-small cell lung cancer.

Molecular pathology--translating research into clinical practice: an expanding frontier in surgical oncology

Molecular assays have now become essential to the pathologist and clinician alike in diagnosing and managing disease. This article highlights the techniques and molecular targets no longer ancillary to basic research. Ripe for discussion are the likely future impact of genetics on clinical care, the potential models for service provision, and the broader ethical, legal, and social issues related to the use of genetic information for nonmedical purposes. Molecular methods are forecasted to increase in assisting in the diagnosis of human diseases. The author's mission is to embrace this discipline and use these technologies in clinical practice.

[Fluorescence in situ hybridization. A new diagnostic dimension in cytology]

Fluorescence in situ hybridization (FISH) is a powerful method for the identification of chromosomal aberrations to improve the diagnostic performance of cytology. FISH is applicable to almost any type of cytological specimen irrespective of cell type, staining or fixation modality. Multi-target tests for the simultaneous analysis of four chromosomes or chromosomal loci improves the sensitivity of cytological diagnosis in bladder and lung cancer and is most helpful in equivocal cytology. FISH also allows a reliable distinction between malignant mesothelioma and reactive mesothelial cells. Specific translocations can easily be detected by FISH for precise diagnosis of lymphomas and sarcomas. Testing for HER-2 amplification has become a standard method to select patients with breast cancer for therapy with trastuzumab. Co-analysis of HPV and selected genes could become a useful approach in gynecological cytology. The spectrum of diagnostic FISH applications is continuously growing.

Fluorescence in situ hybridization in diagnostic cytology

Fluorescence in situ hybridization (FISH) is a technique that uses fluorescently labeled DNA probes to detect chromosomal alterations in cells. FISH can detect various types of cytogenetic alterations including aneusomy (ie, abnormalities of chromosome copy number), duplication, amplification, deletion, and translocation. Because tumor cells generally contain chromosomal alterations, FISH is able to detect cells that have chromosomal abnormalities consistent with neoplasia in exfoliative and aspiration cytology specimens. This review will discuss the utility of FISH for the detection of bladder, lung, pancreatobiliary, and esophageal carcinoma in cytologic specimens.

EGFR expression as an ancillary tool for diagnosing lung cancer in cytology specimens

Lung cancer evolves in a multistep process, and its early detection portends a better prognosis. Bronchial washings/brushings and fine-needle aspirations are often used as early screening and cytological diagnosis of lung cancer. In some cases, it is difficult to differentiate morphologically malignant from reactive cells. Epidermal growth factor receptor (EGFR) is a transmembrane receptor overexpressed in high percentage lung cancers, and contributes to tumor growth. Assessing EGFR expression levels by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) may provide critical information of tumor marker abnormalities, assist in the cytological diagnosis, and stratify patients for EGFR inhibitor therapy. Fifty patients with bronchial washings/brushings or fine-needle aspiration specimens, and corresponding histologically confirmed lung biopsies, were studied for EGFR expression with FISH and IHC. Copy numbers of the EGFR gene locus were analyzed with those of chromosome 7 by FISH. EGFR and FISH results were compared to our FISH data with combined EGFR, c-myc, 5p15.2, and chromosome 6 probes in selected cases. Cell blocks, if available, and tissue biopsy sections were used for EGFR IHC. The intensity of IHC was scored, and quantified. Only balanced aneuploidy of EGFR was identified by FISH. Gene amplification was not detected. The chromosomal abnormalities of EGFR were often accompanied by other chromosomal aneuploidies demonstrated in c-myc (8q24), 5p15.2 or 6p, indicating a general genomic instability. About half of the specimens with confirmed malignancy showed EGFR balanced aneuploidy by FISH, and gene copy number was not coupled with protein expression in many cases. The benign or reactive cytology specimens confirmed by biopsies had high specificity by FISH (96%) and IHC (88%). FISH and IHC analysis of EGFR, possibly along with other tumor markers, may be a useful ancillary tool to classify difficult cytology cases and inform clinicians arranging targeted chemotherapy.

Detection of lung cancer using MAGE A1-6 and SSX4 RT-PCR expression profiles in the bronchial wash fluid

PURPOSE

Bronchial wash fluid may be a useful for detecting lung cancer. To increase the detection rates, we performed molecular analysis with using MAGE A1-6 and SSX4 RT-PCR on bronchial wash fluid specimens.

MATERIALS AND METHODS

We obtained 57 lung cancer tissue specimens by bronchoscopic biopsy and 131 bronchial washes from 96 patients with lung cancer and 35 patients with benign lung diseases. The MAGE A1-6 and SSX4 gene expressions were investigated in the cancer tissue specimens and bronchial wash fluids. We evaluated the positive detection rates of these methods according to the cytology results and the clinical findings.

RESULTS

For the cancer tissue specimens and the bronchial wash fluid, the positive detection rate of MAGE or SSX4 was 91.2% and 75.0%, respectively. Combined MAGE and SSX4 PCR and cytology tests showed an 83.3% detection rate for the bronchial wash fluid. From bronchial washes of patients with benign lung diseases, the positive rates of using MAGE or SSX4 was 11.4%. In the bronchial wash fluid of lung cancer patients, 66.7% of the peripheral cancers were detected by MAGE or SSX4, while examination with cytology did not detect any peripheral lung cancer.

CONCLUSION

The application of both MAGE and SSX4 showed high sensitivity and specificity for the detection of lung cancer. Thus, MAGE and SSX4 RT-PCR may be effectively utilized as additional methods to improve detection of lung cancer with using bronchial wash fluids.

Predicting gefitinib responsiveness in lung cancer by fluorescence in situ hybridization/chromogenic in situ hybridization analysis of EGFR and HER2 in biopsy and cytology specimens

In non-small cell lung cancer (NSCLC), epidermal growth factor receptor (EGFR) mutational analysis is an excellent predictor of responsiveness to treatment with tyrosine kinase inhibitors, such as gefitinib. In up to 80% of NSCLCs, cytologic samples or endoscopic biopsies are the only specimens available for molecular analysis, but PCR amplification of DNA from small fixed and paraffin-embedded samples may create artifactual mutations. Fluorescence in situ hybridization (FISH) of EGFR and HER2 has been proposed as an alternative method of analysis. This project aimed to determine the optimal scoring method for FISH or chromogenic in situ hybridization (CISH) assays when analyzing small NSCLC samples to predict response. FISH or CISH analysis of EGFR and HER2 genes was done on 42 small samples derived from NSCLC patients treated with gefitinib. EGFR mutational analysis was done after quantity and quality controls of DNA. In seven of seven cases, a balanced increase in EGFR gene and chromosome 7 number was found to correlate with the presence of specific EGFR mutations. In addition, seven of seven cases with balanced EGFR/HER2 polysomy and two of three cases with balanced EGFR/HER2 trisomy responded to gefitinib (75% of responders). Instead, the EGFR mutations predicted only 7 of 12 (58%) of gefitinib-responsive patients. When only endoscopic biopsies or cytologic specimens are available, we propose using FISH/CISH for EGFR and HER2 as the test of choice for selecting patients for treatment with gefitinib and to consider as negative predictive factor the absence of EGFR/HER2 gene gain.