Oliner et al., 1992). In addition, it is also thought to function as a regulator of p53 function. This stems from evidence that the MDM2 protein forms oligomeric complexes with the p53 protein in vivo and in vitro (Momand et al., 1992;Oliner et al., 1992) and when experimentally overexpressed inhibits the transactivating capability of p53 (Momand et al., 1992). This inhibition is thought to result from the MDM2 protein binding directly to the acidic activation domain of p53, concealing it from the transcriptional machinery (Oliner et al., 1993). Apart from its role as a p53 regulator, MDM2 also has oncogenic properties, as evident from transfection studies in which MDM2 overexpression was found to increase the tumorigenic potential of NIH3T3 and Rat2 cells (Fakharzadeh et al., 1991) and to overcome wild-type p53 suppression of transformed cell growth (Finlay, 1993 Following hybridisation with a [a-32PJdCLTP-labelled human MDM2 cDNA probe (C14-2), the membranes were exposed to intensifying screens for 2-10 days at -70°C. The blots were subsequently reprobed with the pDCCl.65 probe, which

Dobson L, Conway C, Hanley A, Johnson A, Costello S, O’Grady A, Connolly Y, Magee H, O’Shea D, Jeffers M & Kay E (2010) Histopathology57, 27–38 Image analysis as an adjunct to manual HER-2 immunohistochemical review: a diagnostic tool to standardize interpretationAims:Accurate determination of HER-2 status is critical to identify patients for whom trastuzumab treatment will be of benefit. Although the recommended primary method of evaluation is immunohistochemistry, numerous reports of variability in interpretation have raised uncertainty about the reliability of results. Recent guidelines have suggested that image analysis could be an effective tool for achieving consistent interpretation, and this study aimed to assess whether this technology has potential as a diagnostic support tool.Methods and results:Across a cohort of 275 cases, image analysis could accurately classify HER-2 status, with 91% agreement between computer-aided classification and the pathology review. Assessment of the continuity of membranous immunoreactivity in addition to intensity of reactivity was critical to distinguish between negative and equivocal cases and enabled image analysis to report a lower referral rate of cases for confirmatory fluorescence in situ hybridization (FISH) testing. An excellent concordance rate of 95% was observed between FISH and the automated review across 136 informative cases.Conclusions:This study has validated that image analysis can robustly and accurately evaluate HER-2 status in immunohistochemically stained tissue. Based on these findings, image analysis has great potential as a diagnostic support tool for pathologists and biomedical scientists, and may significantly improve the standardization of HER-2 testing by providing a quantitative reference method for interpretation.

Background and Aims: Trastuzumab provides clinical benefit for advanced and early breast cancer patients whose tumours over-express or have gene amplification of the HER2 oncogene. The UK National External Quality Assessment Scheme (NEQAS) for immunohistochemical testing was established to assess and improve the quality of HER2 immunohistochemical testing. However, until recently, no provision was available for HER2 fluorescence in situ hybridisation (FISH) testing. A pilot scheme was set up to review the performance of FISH testing in clinical diagnostic laboratories. Methods: FISH was performed in 6 reference and 31 participating laboratories using a cell line panel with known HER2 status. Results: Using results from reference laboratories as a criterion for acceptable performance, 60% of all results returned by participants were appropriate and 78% either appropriate or acceptable. However, 22.4% of results returned were deemed inappropriate, including 13 cases (4.2%) where a misdiagnosis would have been made had these been clinical specimens. Conclusions:The results of three consecutive runs show that both reference laboratories and a proportion of routine clinical diagnostic (about 25%) centres can consistently achieve acceptable quality control of HER2 testing. Data from a significant proportion of participating laboratories show that further steps are required, including those taken via review of performance under schemes such as NEQAS, to improve quality of HER2 testing by FISH in the ''real world''.

For a variety of technical reasons it is rarely possible to study cytogenetic abnormalities in ductal carcinoma in situ (DCIS) using traditional techniques. However, by combining molecular biology and computerized image analysis it is possible to carry out cytogenetic analyses on formalin‐fixed, paraffin‐embedded tissue, using comparative genomic hybridization (CGH). The purpose of this study was to identify the prevalence of chromosomal amplifications and deletions in high‐grade DCIS and to look specifically for unique or consistent abnormalities in this pre‐invasive cancer. Twenty‐three cases of asymptomatic, non‐palpable, screen‐detected, high‐grade DCIS were examined using CGH on tumour cells obtained from histology slides. All cases showed chromosomal abnormalities. A wide variety of amplifications and deletions were spread across the genome. The most frequent changes were gains of chromosomes 17 (13 of 23), 16p (13 of 23), and 20q (9 of 23) and amplifications of 11q13 (22 of 23), 12q 24.1–24.2 (12 of 23), 6p21.3 (11 of 23), and 1q31‐qter (6 of 23). The most frequent deletions were on 13q 21.3–q33 (7 of 23), 9p21 (4 of 23), and 6q16.1 (4 of 23). These findings indicate that high‐grade DCIS is, from a cytogenetic viewpoint, an advanced lesion. There was no absolutely consistent finding in every case, but amplification of 11q13 was found in 22 of the 23 cases. The precise significance of this is unknown at present. This region of chromosome 11q harbours a number of known oncogenes, including cyclinD1 and INT2. It is likely that many of these findings are the result of accumulated chromosomal abnormalities, reflecting an unstable genome in established malignancy. Copyright © 1999 John Wiley & Sons, Ltd.