EGFR alterations in pancreatic ductal adenocarcinoma: a chromogenic in situ hybridization analysis based on tissue microarrays.

BACKGROUND/AIMS: To evaluate epidermal growth factor receptor (EGFR) gene status in pancreatic ductal adenocarcinoma correlating the results to protein expression and clinicopathological features METHODOLOGY: Using tissue microarray technology (TMArrayer 100), fifty (n = 50) paraffin-embedded tissue samples of histologically-confirmed primary tumors were cored twice at a diameter of 1 mm and re-embedded into the final recipient block. Immunohistochemistry was performed by the use of anti-EGFR monoclonal antibody (31G7). Also, a chromogenic in situ hybridization protocol was applied based on the use of EGFR gene and chromosome 7 centromeric probes, respectively. RESULTS: EGFR protein overexpression was observed in 29/50 (58%) cases and correlated to stage (p = 0.001) but not to grade (p = 0.206). EGFR gene analysis identified numerical alterations in 6/50 (12%), including 2 cases characterized by low-level gene amplification and 4 by absence of one allele. Gene status was associated to tumor grade (p = 0.023) and stage (p = 0.02). Chromosome 7 analysis detected aneuploidy in 14 (28%) cases. CONCLUSIONS: A subset of pancreatic ductal adenocarcinomas (PDACs) is characterized by EGFR gene numerical alterations including sporadic cases of amplification or absence of one allele (maybe due to gene deletion or intragenic point mutation and allelic silence). Those alternative mechanisms maybe influence the efficacy of novel targeted therapeutic strategies based on monoclonal antibodies or intracellular tyrosine-kinase inhibitors in PDACs.

HER2/neu expression and gene alterations in pancreatic ductal adenocarcinoma: a comparative immunohistochemistry and chromogenic in situ hybridization study based on tissue microarrays and computerized image analysis.

CONTEXT: HER2/neu overexpression is observed in many cancers including pancreatic ductal adenocarcinoma. Although immunohistochemistry remains the basic method for evaluating HER2/neu protein expression, significant information regarding gene status cannot be assessed. DESIGN: Using tissue microarray technology, fifty histologically confirmed pancreatic ductal adenocarcinomas were cored twice and re-embedded in one paraffin block. Immunohistochemistry (clone TAB 250) and chromogenic (HER2/neu amplification Spot Light kit) in situ hybridization protocols were performed. The immunostained slides were evaluated by conventional eye microscopy and digital image analysis. The chi square test and the kappa statistic were applied by running the SPSS package. MAIN OUTCOME MEASURES: The levels of staining intensity were estimated by the performance of a semi automated image analysis system. RESULTS: HER2/neu gene amplification was detected in 8/50 cases (16%). Chromosome 17 aneuploidy was detected in 19 cases (38%). Significant improvement in interobserver agreement (kappa=0.76 vs. 0.94) was achieved correlating the immunohistochemical results obtained by conventional eye and digital microscopy, especially in the cases of overexpression (2+, 3+). Finally, 29 (58%), 11 (22%), 6 (12%) and 4 (8%) cases were characterized as 0, 1+, 2+ and 3+, respectively. HER2/neu protein expression was significantly associated with grade (P=0.019), but not with stage (P=0.466). in addition, chromosome 17 and gene status were not correlated with stage and grade. CONCLUSION: Our results indicate that a subset of pancreatic ductal adenocarcinomas is characterized by HER2/neu gene amplification. In contrast to breast cancer, protein overexpression does not predict this specific gene deregulation mechanism. This event may reflect the different biological role of the molecule in those two solid tumours, affecting the response to novel targeted agents, such as monoclonal anti-HER2/neu antibodies. Furthermore, evaluation of HER2/neu protein expression based on digital image analysis and not only on conventional eye microscopy improves the accuracy and reliability of immunohistochemical estimation, although that does not demonstrate clinical significance and prognostic value in pancreatic ductal adenocarcinoma.

Trends in suicide mortality in the deprived region of Epirus (north-west Greece) during the period 1998-2002.

This study determines the risk factors associated with suicide rates and the investigation of time trends in the deprived region of Epirus, north-west Greece, which is considered to be one of the least developed prefectures of the EU. Data selected demonstrated: (1) a mean age-standardized suicide rate per year of 4.00/100,000 for males, 1.29/100,000 for females and 2.65/100,000 for the total population; (2) a significant rising trend of male suicides in the 35-44 and 65-74 age groups; (3) a low female suicide rate in < 35 years age group and a relatively stable rate in the other age groups; (4) a significantly higher suicide rate in men than in women from both urban and rural areas and in older men from rural areas; (5) higher rates of suicide among widowed men and unmarried women; (6) the use of predominantly violent suicide methods, especially self-shooting, hanging and drowning; (7) a significant peak in the total suicide rate in the spring and summer months and a decreased rate in September; and (8) three out of four of the suicide victims had consumed alcohol and/or other drugs before the act. Data reported here shows some remarkable trends compared to previous reports on suicide in Greece and other countries, probably due to cultural and life style characteristics of the study population.