HER2 gene status in primary breast cancers and matched distant metastases.

INTRODUCTION: The status of the gene encoding human EGF-like receptor 2 (HER2) is an important prognostic and predictive marker in breast cancer. Only breast cancers with HER2 amplification respond to the targeted therapy with trastuzumab. It is controversial to what degree the primary tumour is representative of distant metastases in terms of HER2 status. Discrepancies in HER2 status between primary tumours and distant metastases have been described, but their reasons remain unclear. Here, we compared HER2 status on cytological specimens of distant metastases with the result from the primary carcinomas, and explored the prevalence of and the reasons for discrepant results. METHODS: HER2 status was determined by fluorescence in situ hybridisation. HER2 gene amplification was defined as a HER2/chromosome 17 signal ratio of 2 or more. HER2 results from cytological specimens of matched distant metastases were compared with the results from the corresponding primary tumours (n = 105 patients). In addition, lymph node metastases were analysed in 31 of these patients. RESULTS: HER2 amplification was found in 20% of distant metastases. HER2 status was discordant between the primary tumour and distant metastasis in 7.6% of the 105 patients. Re-evaluation revealed that in five patients (4.7%), discrepancies were due to interpretational difficulties. In two of these patients, focal amplification had initially been overlooked as a result of heterogeneity in the primary tumours or in the metastases, respectively. A further three patients had borderline amplification with a ratio close to 2. Discrepancy remained unexplained in three patients (2.9%). CONCLUSION: HER2 gene status remains highly conserved as breast cancers metastasise. However, discrepant results do occur because of interpretational difficulties and heterogeneity of HER2 amplification. Cytological specimens from distant metastases are well suited for HER2 fluorescence in situ hybridisation analysis.

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.

An international telecytologic quiz on urinary cytology reveals educational deficits and absence of a commonly used classification system.

Urinary cytology is limited by high interobserver variability in the evaluation of cells with little atypia. We set up an online quiz on urinary cytology and tested the performance of 246 international participants. The quiz consisted of still images of 42 urinary specimens with equivocal morphologic features and 10 control cases with an unequivocal cytologic diagnosis. The nature of the cells on the 292 quiz images had been verified by multitarget fluorescence in situ hybridization in addition to the information obtained by cystoscopy, clinical follow up, and/or histologic examination. The original quiz cases and the percentage of answers given by the participants can be viewed at: http://kathrin.unibas.ch/urinzyto/. High-grade cancers were diagnosed correctly in 76.0% and low-grade cancers in only 33.9%. Remarkably, 54.5% of all participants misclassified decoy cells as malignant. This study shows that large-scale international online quizzes may be used to find educational deficits in cytopathology.

Multitarget FISH analysis in the diagnosis of lung cancer.

The aim of the present study was to explore the diagnostic usefulness of the multitarget fluorescence in situ hybridization (FISH) test, LAVysion (Vysis, Downers Grove, IL), for the detection of lung cancer cells in cytologic specimens. Specimens from bronchial washings, bronchial brushings, and transbronchial fine-needle aspirates (TBNAs) from 100 patients with suspected lung cancer and from a control group of 71 patients with nonneoplastic lung disorders were analyzed. FISH positivity was defined as more than 5 cells with gains of at least 2 chromosomes or gene loci. FISH significantly improved the sensitivity of bronchial brushings from 49% to 73%. The specificities of FISH and cytologic examination were 87% and 100%, respectively. In contrast, FISH provided no additional diagnostic information in TBNAs and bronchial washings. There was no increased prevalence of genetic changes in contralateral bronchial washings from patients with lung cancer compared with the control group. The quantity of previous smoking had no effect on the prevalence of chromosomal changes.

Dysplastic cells in cytological cervical samples show a high incidence of chromosomal abnormalities.

Chromosomal abnormalities are frequent in most cervical cancers. Amplifications of both the 3q26 (TERC) and 8q24 (MYC) loci have been shown to be prevalent in both high-grade lesions and invasive cervical carcinoma. Most of these studies have looked at either the histological sample or at the entire cytological population of cells. We have developed a Papanicolaou (Pap) destaining method that allows for the accurate analysis of individual cells that were previously identified by cytopathology as dysplastic. The application of fluorescence in situ hybridization (FISH) was then implemented to determine the chromosomal status of the dysplastic cells in the samples and correlate the two events. Chromosomal abnormality is over a thousand times more frequent in dysplastic cells compared with their morphologically normal counterparts.

An online quiz uncovers limitations of morphology in equivocal lung cytology.

BACKGROUND: Equivocal atypia in respiratory cytology can be a diagnostic challenge. In such cases fluorescence in situ hybridization (FISH) may be used for the analysis of chromosomal aberrations and often allows a reliable distinction of benign and malignant cells. METHODS: An online picture gallery of 30 respiratory cytologic preparations comprising 23 specimens with equivocal cytology as well as 5 positive and 2 negative controls was prepared (www.unibas.ch/patho/lungenzyto/loesung). The final diagnoses were confirmed by clinical follow-up or biopsy or both. Each of the illustrated cell groups was analyzed by multitarget FISH after PAP image capturing and automatic relocalization. RESULTS: The online questionnaire was completed by 137 cytomorphologists from all continents. The control cases were assessed accurately to a significantly higher percentage than the equivocal cases. In equivocal cases participants more often made false-positive than false-negative diagnoses. In 2 patients with benign conditions (tuberculosis and pulmonary capillaritis) the rate of false-positive answers was remarkably high (31.4% and 62.8% respectively). The result of the 20 best-performing participants for the 5 cases with the highest percentage of inaccurate answers was not better than if they had chosen their answer by chance. CONCLUSIONS: These data illustrate that single cells or cell clusters of a subgroup of equivocal lung cytology are a diagnostic challenge even for highly experienced morphologists. Internet-based tests are able to reveal limitations of cytomorphology.