"Sugar" tumor of the pancreas: a rare entity that is diagnosable on preoperative fine-needle biopsies.

This study is the second to report a pancreatic "sugar" tumor (ST) case. This ST was incidentally discovered in a 31-year-old woman using computed tomography scan (CT scan) for work-up of a hepatic focal nodular hyperplasia. Both CT scan and endoluminal ultrasonography (EUS) features evoked a 15-mm large benign endocrine tumor. Pathological examination of EUS-guided fine-needle aspiration biopsies could not confirm this diagnosis. Laparoscopic corporeo-caudal pancreatectomy was performed. The tumor was intrapancreatic, well circumscribed, and organized in sheets of epithelioid cells. The tumor cells expressed HMB-45 but did not express epithelial or endocrine immunohistochemical markers. These histophenotypic features are those of an extra pulmonary ST, which belong to the PEComa family of tumors. Retrospective examination of preoperative biopsies evidenced the same histophenotypic features. This observation highlights that STs should be considered in preoperative differential diagnosis of pancreas tumors, since they may be treated by limited surgical resection.

Protein expression profiling identifies subclasses of breast cancer and predicts prognosis.

Breast cancer is a heterogeneous disease whose evolution is difficult to predict by using classic histoclinical prognostic factors. Prognostic classification can benefit from molecular analyses such as large-scale expression profiling. Using immunohistochemistry on tissue microarrays, we have monitored the expression of 26 selected proteins in more than 1,600 cancer samples from 552 consecutive patients with early breast cancer. Both an unsupervised approach and a new supervised method were used to analyze these profiles. Hierarchical clustering identified relevant clusters of coexpressed proteins and clusters of tumors. We delineated protein clusters associated with the estrogen receptor and with proliferation. Tumor clusters correlated with several histoclinical features of samples, including 5-year metastasis-free survival (MFS), and with the recently proposed pathophysiologic taxonomy of disease. The supervised method identified a set of 21 proteins whose combined expression significantly correlated to MFS in a learning set of 368 patients (P < 0.0001) and in a validation set of 184 patients (P < 0.0001). Among the 552 patients, the 5-year MFS was 90% for patients classified in the "good-prognosis class" and 61% for those classified in the "poor-prognosis class" (P < 0.0001). This difference remained significant when the molecular grouping was applied according to lymph node or estrogen receptor status, as well as the type of adjuvant systemic therapy. In multivariate analysis, the 21-protein set was the strongest independent predictor of clinical outcome. These results show that protein expression profiling may be a clinically useful approach to assess breast cancer heterogeneity and prognosis in stage I, II, or III disease.

[Periampullar gangliocytic paraganglioma resected by surgical ampullectomy: a case report]. / Paragangliome gangliocytique péri-ampullaire traité par ampullectomie chirurgicale.

We report the case of a 40-Year-old woman with duodenal gangliocytic paraganglioma of the ampulla of Vater. Preoperative diagnosis was periampullar tumor. Final diagnosis of duodenal gangliocytic paragangioma of the ampulla of Vater with negative margins was made by histological and immunohistochemical study of surgical ampullectomy specimen. This case report stresses the yield of immunohostochemical study in the diagnosis of duodenal gangliocytic paraganglioma, a rare entity.

Immunophenotypic analysis of inflammatory breast cancers: identification of an 'inflammatory signature'.

Inflammatory breast cancer (IBC) is a rare but very aggressive form of breast cancer. Its definition is based on clinical criteria, but a molecular definition could be useful when data are incomplete or features are missing. Recently, the identification of overexpression of E-cadherin in IBC has improved understanding of the molecular basis of this disease. Consequently, the aim of this study was to try to determine an immunophenotypic 'signature' of IBC. A series of 80 cases of IBC were compared with 552 non-IBC control cases and a model was elaborated to evaluate the probability of an inflammatory carcinoma being present in any clinical situation. Tissue microarrays (TMAs) were used to determine the immunohistochemical profile of eight proteins including E-cadherin, EGFR, oestrogen and progesterone receptor (ER and PR), MIB1, ERBB2, MUC1, and P53. All the parameters tested were differentially expressed between IBC and control cases in univariate analysis (p < 0.001). The five variables that were significantly associated with IBC in multivariate analysis were E-cadherin > or = 300 [HR = 5.64 (2.92-10.87)], ER negative [HR = 3.00 (1.67-5.51)], MIB1 > 20 [HR = 3.54 (1.87-6.71)], MUC1 cytoplasmic staining [HR = 2.72 (1.49-4.96)], and ERBB2 positive 2+ or 3+ [HR = 2.46 (1.26-4.78)]. The probability that a breast cancer with this full phenotype at diagnosis was an IBC was 90.5%. If any one of the five parameters was missing, this probability dropped to 75% and was less than 50% when one, two, or three parameters were present. The 5-year overall survival (OS) and 5-year disease-free survival (DFS) of patients with IBC were not significantly different from those of the non-IBC control group that expressed four or five parameters (nIBC-1), but this nIBC-1 control group had a significantly worse outcome than the non-IBC control group (nIBC-2) with only 0-3 parameters (p = 0.0049 for OS and p < 0.0001 for DFS). In conclusion, an immunophenotypic signature was suggested for IBC. This could help to determine the worst cases, independent of clinical criteria.

Comparative multi-methodological measurement of ERBB2 status in breast cancer.

The ERBB2 transmembrane tyrosine kinase receptor is both a prognostic marker and a therapeutic target in breast cancer. Accurate determination of ERBB2 status is a prerequisite for the establishment of prognostic significance and for the selection of ERBB2-overexpressing breast tumours for specific treatment. Unfortunately, there is no complete agreement on how this determination should be performed. This study has compared four methods of assessment of ERBB2 status. Two global, extraction-based methods using real-time quantitative PCR on DNA (Q-PCR) or RNA (RQ-PCR) and two non-global, tissue-based methods, ie fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC), were used. The 94 breast cancers tested were enriched in cases scoring 2+ using the IHC scoring system currently in use and for which the actual ERBB2 status remains ill defined. To determine the best parameters and reagents for assessment, two protocols for FISH and five anti-ERBB2 antibodies were used, and both FISH and IHC were carried out on the same tissue microarrays (TMAs). It is shown that the combination of the two tissue-based methods gives the best results. The use of either PCR-based method did not improve the results significantly. A new combined IHC score based on the association of two selected anti-ERBB2 antibodies (HercepTest trade mark and TAB250) and a dual scale for improved assessment of ERBB2 protein expression, particularly in 2+ cases, are proposed.

Identification and validation of an ERBB2 gene expression signature in breast cancers.

ERBB2 is a transmembrane tyrosine kinase receptor encoded by a gene located in chromosome region 17q12. Overexpression of ERBB2, generally by way of gene amplification, plays a role in mammary oncogenesis. This alteration can be overcome by use of the humanized monoclonal antibody trastuzumab (Herceptin). Accurate determination of ERBB2 status is required for appropriate use of this targeted therapy and is currently analysed by immunohistochemistry (IHC) on tissue sections and/or fluorescence in situ hybridisation (FISH) on interphase chromosomes. We have studied the gene expression profiles of a series of 213 breast tumours and 16 breast cancer cell lines with known ERBB2 status, using Ipsogen's DiscoveryChip microarrays with approximately 9000 cDNAs. We have identified 36 genes and expressed sequence tags that were differentially expressed in tumours and in cell lines with and without ERBB2 protein overexpression. This ERBB2-specific gene expression signature (GES) contained 29 overexpressed genes including the ERBB2 gene itself, five genes located in its immediate vicinity on 17q12, non-17q genes such as GATA4 and eight downregulated genes including oestrogen receptor alpha (ER). Some correlations were validated at the protein level using IHC on tissue microarrays. The GES was able to distinguish ERBB2-negative and -positive cancer samples, as well as FISH-negative and FISH-positive ERBB2 2+ IHC samples.

Loss of FHIT protein expression is a marker of adverse evolution in good prognosis localized breast cancer.

The FHIT tumor suppressor gene, which encompasses the fragile site FRA3B at 3p14.2, is altered frequently in many types of human cancers. To determine its importance as a prognostic marker in breast cancer, the expression of the FHIT protein was studied in a series of 452 breast carcinomas by using immunohistochemistry on sections of tissue microarrays. Three distinct levels of FHIT expression were observed: in 154 cases (34.1%) expression was unchanged as compared to normal level; in 78 (17.2%) no expression was found; in the remaining 220 cases (48.7%), expression was intermediate. Overall, two-thirds of the cases had abnormal levels of the protein. Absence of FHIT was significantly associated with a higher grade (p < 0.01) and absence of hormone receptors (p < 0.001). The patients were separated into Group I (153 node-negative good prognosis patients who did not receive adjuvant chemotherapy) and Group II (226 high-risk patients treated by adjuvant chemotherapy) according to the St.-Gallen conference consensus. The median follow-up was 48 months. Among Group I but not Group II patients, a multivariate analysis showed that FHIT expression was significantly associated with disease-free survival. The relative risk of recurrence for FHIT-negative Group I patients was 2.37 (1.21-4.64; p = 0.03). Thus, among the patients who present with tumors of apparent good prognosis, FHIT is an independent prognostic factor that distinguishes a subgroup of patients who could benefit from adjuvant treatment.

Constitutive nuclear localization and initial cytoplasmic apoptotic activation of endogenous caspase-3 evidenced by confocal microscopy.

The localization of caspases and their substrates in different cellular compartments may be one way to regulate apoptosis. Caspase-3-dependent proteolysis of inhibitor caspase-activated deoxyribonuclease (ICAD) activates caspase-activated deoxyribonuclease (CAD), which induces apoptotic internucleosomal DNA degradation. The nuclear localization of ICAD, pro- and active-caspase-3 molecules remains a controversial issue. Using a combination of immunodetection of endogenous molecules and confocal microscopy, we analysed the kinetics of the procaspase-3 and CAD activation induced by FAS triggering in Jurkat cells. Through a semi-quantitative image analysis, we showed a constitutive nuclear localization of pro-caspase 3 and ICAD in non-apoptotic cells. FAS stimulation induced 7A6 apoptotic antigen expression, which could be related to three different sequential patterns of nuclear chromatin organization. Active-caspase-3 first appeared in the cytoplasm and was next observed in the nucleus. Simultaneously, the amount of ICAD located in the nucleus decreased, whereas the amount of ICAD located in the cytoplasm remained unchanged. Thus, our experiments using in situ immunodetection of endogenous molecules show that the ICAD cleavage by the active-caspase-3 probably takes place in the nucleus. These results provide new perspectives about the subcellular compartmentation and traffic of caspases during the apoptotic process.

[Inflammatory breast carcinoma: towards molecular characterization?]. / Carcinome inflammatoire du sein: vers une définition moléculaire?

Inflammatory Breast Carcinoma (IBC) is a rare but aggressive form of breast carcinoma. Characteristic clinical and pathological features are well documented. Pathological response to chemotherapy is currently the only identified prognostic factor. This high-grade tumor exhibits phenotypical features of an aggressive tumor: absence of hormonal receptors in 56 to 83% of cases, high proliferating index, p53 expressed in 30 to 69%, Immunohistochemistry (IHC) detection of HER2 over expression in 38 to 60%. Current work on IBC points out specific molecular mechanisms: adhesion molecules such as E-Cadherin, apomucin MUC1 and angiogenesis processes contribute to the IBC phenotype. So does a gene named WISP3. This gene has been recently cloned and sequenced. It has been shown to be lost in IBC and could control tumor growth, invasion, and angiogenesis. This paper summarizes current knowledge on IBC and describes a new basis for a molecular definition of IBC.

Loss of heterozygosity at microsatellite markers from region p11-21 of chromosome 8 in microdissected breast tumor but not in peritumoral cells.

Alterations of chromosomal region 8p11-21 are very frequent in human cancers, and especially in breast cancer; yet, most of the genes involved have not been identified. We performed laser capture microdissection in a series of 52 consecutive breast tumor samples to obtain pure tumor cells without surrounding normal breast. To determine genomic subregions in which some of the cancer genes may be located, we conducted a search for loss of heterozygosity (LOH) at 13 microsatellite markers from this region. Two-thirds of the tumors showed LOH at least at one marker. Microdissection of pure tumor samples was helpful to precisely define four LOH subregions. No LOH was observed in the corresponding peritumoral tissues. We studied by immunohistochemistry (IHC) on tissue-microarrays the expression in the same tumors, of the protein product of three potential tumor genes lying close to or within the subregions of LOH. In most samples, the TACC1 gene product was downregulated in tumor cells as compared to normal cells. Our results show that the centromeric portion of chromosome arm 8p is frequently altered in breast tumor cells.