Topoisomerase II alpha gene copy loss has adverse prognostic significance in ERBB2-amplified breast cancer: a retrospective study of paraffin-embedded tumor specimens and medical charts.

BACKGROUND: Amplification of the ERBB2 (Her-2/neu) oncogene, which occurs in approximately 25% of breast carcinomas, is a known negative prognostic factor. Available data indicate that a variable number of nearby genes on chromosome 17q may be co-amplified or deleted, forming a continuous amplicon of variable size. In approximately 25% of these patients, the amplicon extends to the gene for topoisomerase II alpha (TOP2A), a target for anthracyclines. We sought to understand the significance of these associated genomic changes for breast cancer prognosis and predicting response to therapy. METHODS AND PATIENTS: Archival tissue samples from 63 breast cancer patients with ERBB2 amplification, stages 0-IV, were previously analyzed with FISH probes for genes located near ERBB2. In the present study, the clinical outcome data were determined for all patients presenting at stages I-III for whom adequate clinical follow up was available. RESULTS: Four amplicon patterns (Classes) were identified. These were significantly associated with the clinical outcome, specifically, recurrence of breast cancer. The Amplicon class IV with deleted TOP2A had 67% (6/9) cases with recurrence, whereas the other three classes combined had only 12% (3/25) cases (p-value = 0.004) at the time of last follow-up. TOP2A deletion was also significantly associated with time to recurrence (p-value = 0.0002). After adjusting for age in Cox regression analysis, the association between TOP2A deletion and time to recurrence remains strongly significant (p-value = 0.002) whereas the association with survival is marginally significant (p-value = 0.06). CONCLUSION: TOP2A deletion is associated with poor prognosis in ERBB2-amplified breast carcinomas. Clarification of the mechanism of this association will require additional study.

Chromosome 1 analysis in chromophobe renal cell carcinomas with tissue microarray (TMA)-facilitated fluorescence in situ hybridization (FISH) demonstrates loss of 1p/1 which is also present in renal oncocytomas.

Morphologic overlap between chromophobe renal cell carcinoma (ChRCC) and renal oncocytomas (RO) has been widely recognized. Whether these tumors are genetically related and represent a spectrum of benign to malignant tumor progression remains an open question. We previously showed by conventional cytogenetics and fluorescent in situ hybridization (FISH) that the most common chromosomal abnormality in RO is loss of chromosome 1 or 1p. In this study, we evaluated chromosome 1 in ChRCC using the same set of FISH probes. Twenty-one ChRCCs from 13 men and 8 women were studied. Formalin-fixed, paraffin-embedded tissue blocks were used to construct tissue microarrays. A subtelomeric 1p36.3 probe was used in tandem with 1q25 probes for FISH studies. The patients ranged in age from 34 to 82 years (mean 62.8 y, median 61 y). FISH analysis showed an abnormal chromosome 1 in 20/21 (95%) ChRCCs as follows: 18 tumors (85%) had loss of entire chromosome 1, 2 tumors (10%) had loss of 1p36.3 only, and 1 tumor (5%) was apparently diploid for chromosome 1. In this study, 95% of ChRCCs showed abnormality of chromosome 1 by FISH. The progression of chromosome 1 abnormalities, from diploid to loss of 1p to loss of entire chromosome, is also present in oncocytomas. These results provide further evidence to support a genetic similarity between chromophobe carcinoma and oncocytoma. Whether abnormalities of chromosome 1 are associated with RO tumorigenesis or its progression to carcinoma requires further studies.

High incidence of chromosome 1 abnormalities in a series of 27 renal oncocytomas: cytogenetic and fluorescence in situ hybridization studies.

CONTEXT: It has recently been shown by cytogenetics that there is a high incidence of chromosome 1 abnormalities in renal oncocytomas. OBJECTIVE: To confirm the cytogenetic results by fluorescence in situ hybridization (FISH) analysis. DESIGN: Nine additional cytogenetic analyses were added to those reported in our recent study, with a total of 27 tumors studied, which makes it the largest series of renal oncocytomas studied to date by cytogenetics and/or FISH. We used the LSI 1p36/LSI 1q25 Dual Color Probe Set to make the analyses. RESULTS: In this study, combined cytogenetics and FISH showed loss of chromosome arm 1p1 in 48% of renal oncocytomas. By FISH, deletion of 1p36.3 was observed in 59% of renal oncocytomas, whereas by cytogenetics, abnormality in chromosome 1 was seen in 32% of tumors. However, the incidence of chromosome 1 abnormalities among 9 bilateral tumors was much higher than in single tumors (88% vs 28%, respectively). Loss of only the 1p36.3 site occurred in 2 renal oncocytomas with translocation of chromosome 1, as shown by cytogenetics. Concordance between the 2 techniques, when they were used simultaneously to detect chromosome 1p1 abnormality, was 82%. CONCLUSIONS: This study further confirmed our prior results demonstrating the widespread occurrence of chromosome 1 abnormalities in renal oncocytomas. Although no abnormalities in chromosome 1 in tumors with normal karyotypes were detected by FISH using the current set of probes, a much higher incidence of such abnormalities was found in bilateral tumors, suggesting that genetic alterations related to the development of renal oncocytoma reside in this region.

Gene copy mapping of the ERBB2/TOP2A region in breast cancer.

ERBB2 is one of the most important oncogenes in breast cancer, and its disordered expression is commonly associated with gene amplification. Amplification of at least one gene near ERBB2, topoisomerase IIalpha (TOP2A), has been shown to be clinically significant, but the prevailing patterns of gene amplification in this region of chromosome arm 17q have not been studied systematically in clinical cases of breast cancer. For characterizing this region, a commercial ERBB2-containing contig probe and 7 probes prepared from single overlapping BAC and P1 clones lying telomeric to ERBB2 and including TOP2A were hybridized to 77 ERBB2-amplified archival breast tumor specimens from 75 patients. The 7 single-clone probes covered a region of approximately 650 kb starting 114 kb telomeric to ERBB2. Amplification of the ERBB2 contig target alone was found in 32% of the tumors, whereas all 8 probe targets were amplified in 12% of the tumors, based on an amplification criterion of there being more than or equal to 2 targets per chromosome 17 centromere. When one of the 7 overlapping probes encompassing TOP2A indicated amplification within a specimen, all probes telomeric to that probe usually showed amplification. Only 5 specimens had regions of normal or deleted targets separating 2 amplified targets. Also, tumors that showed deletion of TOP2A usually showed deletion of one or more contiguous targets. The observed patterns of amplification and deletion are consistent with the break-fusion-bridge model for gene amplification. TOP2A was amplified in 25% of all tumor specimens and was deleted in 24%, based on a deletion criterion of there being fewer than or equal to 0.75 targets per chromosome 17 centromere. Considering the relevance of the TOP2A gene product to anthracycline therapy and the wealth of other cancer-associated genes within the ERBB2/TOP2A region, the pattern of amplification and deletion near ERBB2 and TOP2A may have a dramatic effect on the malignant potential of breast carcinomas and their response to therapy.

Nurse-administered propofol sedation without anesthesia specialists in 9152 endoscopic cases in an ambulatory surgery center.

Narcotics and benzodiazepines are commonly used for sedation for endoscopy in the United States. Propofol has certain advantages over narcotics and benzodiazepines, but its use is often controlled by anesthesia specialists. This report describes our experience with dosage, safety, patient satisfaction, and discharge time with nurse-administered propofol sedation in 9152 endoscopic cases. The study was performed in a private practice ambulatory surgery center in Medford, Oregon. With the assistance of an anesthesiologist, we developed a protocol for administration of propofol in routine endoscopic cases, in which propofol was given by registered nurses under the supervision of endoscopists or gastroenterologists. We then applied the protocol with 9152 patients. There were seven cases of respiratory compromise (three prolonged apnea, three laryngospasm, one aspiration requiring hospitalization), all associated with upper endoscopy. Five patients required mask ventilation, but none required endotracheal intubation. There were seven colonic perforations (<1 per 1000 colonoscopies), of which three may have involved forceful sigmoid disruption. Of patients who had previously received narcotic or benzodiazepine sedation, 84% preferred propofol. Gastroenterologists strongly preferred propofol. The mean time from completion of procedures to discharge in a sample of 100 patients was 18 min.Nurse-administered propofol sedation in an ambulatory surgery center was safe and resulted in high levels of patient satisfaction and rapid postprocedure recovery and discharge.

Detection of chromosomal instability in paired breast surgery and ductal lavage specimens by interphase fluorescence in situ hybridization.

PURPOSE: Ductal lavage is a new modality for collecting exfoliated breast cells with the goal of detecting early neoplasia. The purpose of our study was to evaluate the correlation between cancer-associated abnormalities in breast lesions and exfoliated breast cells collected by ductal lavage. EXPERIMENTAL DESIGN: We performed histopathologic, cytologic, and molecular cytogenetic analyses on 39 paired cases of surgically excised breast lesions and ductal lavage specimens collected immediately before surgery. RESULTS: Abnormal cytology was detected in 7 of 15 (47%) of the evaluable lavages collected from malignant cases, versus 4 of 19 (21%) of the evaluable lavages harvested from benign cases for a sensitivity and specificity of 47 and 79%, respectively. Interphase fluorescence in situ hybridization analysis of all evaluable lavages revealed numeric changes on chromosomes 1, 8, 11, and/or 17 in 10 of 14 (71%) specimens from malignant cases versus 2 of 18 (11%) from benign cases for a sensitivity and specificity of 71 and 89%, respectively. CONCLUSIONS: Our study demonstrates that cytologic and genetic abnormalities associated with breast cancer progression can be detected in ductal lavage cells collected from women with in situ and invasive breast cancer and suggests that fluorescence in situ hybridization may have superior sensitivity and specificity compared with conventional cytology.

A fluorescence in situ hybridization-based assay for improved detection of lung cancer cells in bronchial washing specimens.

BACKGROUND: Interphase fluorescence in situ hybridization (FISH) is a powerful tool for detecting chromosome and locus-specific changes in tumor cells. We developed a FISH-based assay to detect genetic changes in bronchial washing specimens of lung carcinoma patients. METHODS: The assay uses a mixture of fluorescently labeled probes to the centromeric region of chromosome 1 and to the 5p15, 8q24 (site of the c-myc gene), and 7p12 (site of the EGFR gene) loci to assess cells in bronchial washing specimens for chromosomal abnormalities indicative of lung carcinoma. The FISH assay was performed on 74 specimens that had been assessed previously for evidence of malignancy by routine cytology with Pap staining. RESULTS: Forty-eight patients had histologically confirmed lung carcinoma and 26 patients had a clinical diagnosis that was negative for lung carcinoma. FISH analysis was performed without knowledge of the patient's clinical information. The finding of six or more epithelial cells with gains of two or more chromosome regions was considered a positive FISH result (i.e., evidence of malignancy). The sensitivity of FISH for the detection of lung carcinoma was 82% in this set of specimens compared with a 54% sensitivity by design for cytology (FISH vs. cytology, P = 0.007). FISH detected 15 of 18 specimens that were falsely negative by cytology. The specificities of FISH and cytology were 82% and 100%, respectively, and were not significantly different (P = 0.993). CONCLUSIONS: The data indicate a potential utility of the FISH assay as an adjunct to bronchial washing cytology in routine clinical practice.

Amplification and overexpression of topoisomerase IIalpha predict response to anthracycline-based therapy in locally advanced breast cancer.

PURPOSE: The putative association between erbB-2 overexpression and favorable response to anthracyline-based therapy in breast cancer is controversial, and the mechanism unclear. We sought to determine whether coamplification and overexpression of the topoisomerase IIalpha gene, near erbB-2 on chromosome 17, and a known anthracycline target, may underlie the association. EXPERIMENTAL DESIGN: Thirty-five patients who had locally advanced breast cancer (LABC) and who had received neoadjuvant, anthracycline-based therapy were studied. Copy number of topoisomerase IIalpha and erbB-2 was determined by fluorescence in situ hybridization, and expression by immunohistochemistry. RESULTS: Of 8 patients with erbB-2 amplification, 5 had a complete response (CR) or minimal residual disease (MRD), 3 had a partial response (PR), and none had stable (StD) or progressive disease (PD) at the time of mastectomy, versus 3 CR or MRD, 16 PR, and 8 StD or PD for patients without amplification (P = 0.008). In contrast, erbB-2 overexpression was not significantly associated with response (P = 0.114). Of 6 patients with topoisomerase IIalpha amplification, 4 had CR or MRD, 2 PR, and none StD or PD, versus 4 CR or MRD, 17 PR, and 8 StD or PD for patients without amplification (P = 0.034). All of the tumors with topoisomerase IIalpha amplification also had erbB-2 amplification, but not vice versa. Overexpression of topoisomerase IIalpha (9 patients) was also associated with favorable response (P = 0.021). CONCLUSIONS: Coamplification of erbB-2 and topoisomerase IIalpha is significantly associated with favorable local response to anthracycline-based therapy in LABC. The expression data favor a plausible mechanism based on topoisomerase IIalpha biology.