Quantitative detection of lung cancer cells by fluorescence in situ hybridization: comparison with conventional cytology

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.

CEP3 and CEP17 DNA probe potential in the genetic diagnosis and prognostic prediction of esophageal squamous cell cancer

The aim of the present study was to investigate the clinical application of molecular pathological diagnosis for the prognosis of Kazakh patients with esophageal squamous cell carcinoma (ESCC) using centromere enumeration probes (CEPs) for chromosomes 3 and 17. A total of 40 patients with ESCC that had received radical surgical treatment and 10 healthy control participants were enrolled in the present study. Touch preparations of fresh cancerous and normal tissues were completed and fluorescence in situ hybridization (FISH) was performed to count the copy numbers of CEP 3 and 17, and abnormalities were analyzed, in comparison with routine pathological diagnoses. FISH analysis demonstrated that abnormal copy numbers of CEP 3 and 17 (aneuploidy) were detected in all 40 patients with ESCC. CEP 3 and 17 polyploidy rates differed significantly between poorly differentiated, moderately differentiated and well-differentiated ESCC groups (P<0.05): Well-differentiated, 35.38 and 30.92%; moderately differentiated, 55.81 and 44.43%; and poorly differentiated, 76.26 and 71.90%, respectively. Furthermore, polyploidy rates were significantly increased in the group with lymph node metastasis, as compared with the group without (CEP 3, P=0.0001; CEP 17, P=0.012). Variations in the copy numbers of CEP 3 and 17 were demonstrated to be correlated with the level of differentiation and lymph node metastasis in patients with ESCC. Therefore, the present results indicate that DNA probes may be used to predict prognostic factors in patients with ESCC. Furthermore, FISH technology is an objective and qualitative method that is capable of detecting variations in CEP 3 and 17; therefore, FISH may be used in the genetic diagnosis of ESCC in Kazakh patients.

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.

Molecular pathological diagnosis for early esophageal cancer in Kazakh patients

Chromosome abnormalities in cancer cells occur early in carcinogenesis. We employed DNA probes for the detection of cancer cells in surgical specimens in Kazakh patients with suspected esophageal carcinoma, to analyze the application of this technique during the early diagnosis of esophageal cancer. Comparative analysis was used to compare the results of pathological diagnosis with the results of FISH. We performed esophagofiberscopic biopsy examinations in 50 Kazakh patients with suspected esophageal carcinoma, including 40 males and 10 females, with an average age of 56.8 years. The final diagnosis was esophageal squamous cell carcinoma in 47 patients, and adenocarcinoma, mucinous carcinoma and small cell carcinoma in one patient each. The pathological findings of the biopsy were positive in 45 cases, and false-negative in 5. The sensitivity and specificity of pathological diagnosis were 87.2 and 100%, respectively. Using FISH to examine the same tissues, we found that 48 cases showed aberrant copy numbers in either chromosome 3 or 17, and 2 cases were false-negative, with a sensitivity and specificity of 94.8 and 100%, respectively. The copy numbers of centromeres in chromosome 3 were significantly higher than the copy numbers of centromeres in chromosome 17 (P=0.0001). Compared with biopsy pathology, the FISH test was more sensitive. Being an objective and qualitative method, the technology of molecular pathological diagnosis may effectively increase the early diagnostic rate of esophageal cancer. In addition, the centromere probe in chromosome 3 may be the most sensitive probe for the diagnosis of esophageal cancer in Kazakh patients.

Genetic diagnosis of patients with esophageal cancer using FISH

This study aimed to the clarify the diagnostic efficacy of fluorescence in situ hybridization (FISH) in Kazakh patients with esophageal cancer (EC). FISH was compared with the pathological examination of biopsy specimens with DNA probes. We enrolled 20 patients, of which 15 were males and 5 females, with an average age of 58.3 years, who had abnormal esophaguses on barium radiological digital imaging. Touch preparations were performed on biopsy specimens from all of the patients and were examined using FISH for chromosomal abnormalities. We compared the FISH results with the pathology slides stained with hematoxylin and eosin. Classification, according to pathology, identified 2 cases of class II, 3 cases of IIIa, 1 case of IIIb, 2 cases of IV, 12 cases of class V and no cases of class I. The cases classified as class IIIb or higher were considered to be positive for cancer. Using histopathology, 10 cases were diagnosed with squamous cell carcinoma and 5 were diagnosed as adenocarcinoma, with one case being false-negative. Thus, the sensitivity of the pathological examination was 93% and the specificity was 100%. Using FISH, 16 cases showed aberrant copy numbers in either chromosome 3 or 17. By comparison, pathology did not reveal any false-positive or false-negative cases with a sensitivity and specificity of 100%. The centromeres of chromosome 3 copy numbers was significantly higher (p=0.035) than the centromeres of chromosome 17. Our study compared FISH to diagnose aneusomic esophageal cancer cells with the pathology of biopsied tissue. Our findings suggest that FISH is a useful and objective assay for the detection of malignant cells of esophageal cancer. In our study, the centromeres of chromosome 3 was the more sensitive probe for the diagnosis of esophageal cancer in Kazakh patients.

The use of genetic markers to identify lung cancer in fine needle aspiration samples

PURPOSE

We seek to establish a genetic test to identify lung cancer using cells obtained through computed tomography-guided fine needle aspiration (FNA).

EXPERIMENTAL DESIGN

We selected regions of frequent copy number gains in chromosomes 1q32, 3q26, 5p15, and 8q24 in non-small cell lung cancer and tested their ability to determine the neoplastic state of cells obtained by FNA using fluorescent in situ hybridization. Two sets of samples were included. The pilot set included six paraffin-embedded, noncancerous lung tissues and 33 formalin-fixed FNA specimens. These 39 samples were used to establish the optimal fixation and single scoring criteria for the samples. The test set included 40 FNA samples. The results of the genetic test were compared with the cytology, pathology, and clinical follow-up for each case to assess the sensitivity and specificity of the genetic test.

RESULTS

Nontumor lung tissues had < or= 4 signals per nucleus for all tested markers, whereas tumor samples had > or = 5 signals per nucleus in five or more cells for at least one marker. Among the 40 testing cases, 36 of 40 (90%) FNA samples were analyzable. Genetic analysis identified 15 cases as tumor and 21 cases as nontumor. Clinical and pathologic diagnoses confirmed the genetic test in 15 of 16 lung cancer cases regardless of tumor subtype, stage, or size and in 20 of 20 cases diagnosed as benign lung diseases.

CONCLUSIONS

A set of only four genetic markers can distinguish the neoplastic state of lung lesion using small samples obtained through computed tomography-guided FNA.

Chromosomal instability is a risk factor for poor prognosis of adenocarcinoma of the lung: Fluorescence in situ hybridization analysis of paraffin-embedded tissue from Korean patients

BACKGROUND

In this study, we sought to evaluate the prognostic importance of chromosomal instability (CIN) in adenocarcinoma (AC) of the lung. The relationship between CIN detected by fluorescence in situ hybridization (FISH) and survival in AC patients was examined.

METHODS

Sixty-three surgical specimens of lung AC 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 sex, age, histology, T factor, N factor, CIN, and smoking status. A sample was classified as CIN-positive if at least three of the five chromosomes were positive.

RESULTS

Out of the 63 specimens, 32 (39.7%) were CIN-positive. The 5-year overall disease-free survival rate was 58.7% as a whole, 46.9% for CIN-positive patients and 71.0% for the CIN-negative patients [hazard ratio (HR), 2.34; 95% confidence interval (CI), 1.04-5.26; p = 0.04]. The 5-year overall survival rate was 81.0%, 68.7% for CIN-positive patients and 93.5% for the CIN-negative patients (HR, 5.64; 95% CI, 1.23-25.70; p = 0.026). In multivariate analysis after adjusting for pathologic nodal staging, tumor staging, sex, age, and smoking history, compared with the CIN-negative patients, the CIN-positive status remained significantly associated with decreased overall survival (HR, 8.48; 95% CI, 1.66-43.42; p = 0.010).

CONCLUSIONS

CIN can be effectively detected in primary AC of lung using FISH analysis. CIN is associated with poor prognosis for AC, and may thus be utilized as an independent prognostic factor for the disease.

Multitarget Fluorescence In Situ Hybridization Elucidates Equivocal Lung Cytology

The category of equivocal respiratory cytology is a common diagnostic dilemma to both cytopathologists and clinicians. Chromosomal alterations are a hallmark of cancer but are rare or absent in benign conditions. The goal of this study was to test the ability of multitarget fluorescence in situ hybridization (FISH) for dissecting equivocal respiratory cytology into reactive and malignant categories. A consecutive series of 54 Papanicolaou-stained cytologic specimens of the lung was analyzed. The Papanicolaou-stained atypical cell groups were photographed, and the exact locations on the specimens were saved using automated stage and relocation software. The specimens were hybridized with a multitarget FISH probe that contains a mixture of fluorescent probes to the centromeric region of chromosome 6 and to the 5p15, 8q24 (site of the MYC gene) and 7p12 (site of the EGFR gene) loci. The hybridized atypical cells were selectively scored after relocation. A final diagnosis was available in 45 patients, revealing lung carcinoma in 55.5% (n = 25), no evidence of malignancy in 37.8% (n = 17), and pulmonary metastasis of another primary carcinoma in 6.7% (n = 3). FISH results were negative in all 17 patients with benign pulmonary disease and positive in 20 of the 25 patients (80%) with lung carcinoma (p < 0.0001). The sensitivity, specificity, and positive and negative predictive values for detection of malignancy were 79%, 100%, 100%, and 74%, respectively. These data suggest that multitarget FISH in conjunction with automated relocation is a powerful approach for the elucidation of equivocal lung cytology.