Fluorescence in situ hybridization to visualize genetic abnormalities in interphase cells of acinar cell carcinoma, ductal adenocarcinoma, and islet cell carcinoma of the pancreas.

OBJECTIVE: To use fluorescence in situ hybridization (FISH) to visualize genetic abnormalities in interphase cell nuclei (interphase FISH) of acinar cell carcinoma, ductal adenocarcinoma, and islet cell carcinoma of the pancreas. PATIENTS AND METHODS: Between April 4, 2007, and December 4, 2008, interphase FISH was used to study paraffin-embedded preparations of tissue obtained from 18 patients listed in the Mayo Clinic Biospecimen Resource for Pancreas Research with a confirmed diagnosis of acinar cell carcinoma, ductal adenocarcinoma, islet cell carcinoma, or pancreas without evidence of neoplasia. FISH probes were used for chromosome loci of APC (see glossary at end of article for expansion of all gene symbols), BRCA2, CTNNB1, EGFR, ERBB2, CDKN2A, TP53, TYMP, and TYMS. These FISH probes were used with control probes to distinguish among various kinds of chromosome abnormalities of number and structure. RESULTS: FISH abnormalities were observed in 12 (80%) of 15 patients with pancreatic cancer: 5 of 5 patients with acinar cell carcinoma, 5 of 5 patients with ductal adenocarcinoma, and 2 (40%) of 5 patients with islet cell carcinoma. All 3 specimens of pancreatic tissue without neoplasia had normal FISH results. Gains of CTNNB1 due to trisomy 3 occurred in each tumor with acinar cell carcinoma but in none of the other tumors in this study. FISH abnormalities of all other cancer genes studied were observed in all forms of pancreatic tumors in this investigation. CONCLUSION: FISH abnormalities of CTNNB1 due to trisomy 3 were observed only in acinar cell carcinoma. FISH abnormalities of genes implicated in familial cancer, tumor progression, and the 5-fluorouracil pathway were common but were not associated with specific types of pancreatic cancer.

Validation of a new three-color fluorescence in situ hybridization (FISH) method to detect CHIC2 deletion, FIP1L1/PDGFRA fusion and PDGFRA translocations.

The PDGRFA locus has become a gene of interest based on mutational activation in various myeloid neoplasms and the availability of targeted therapies (i.e., imatinib mesylate) to its overexpression. We studied a new FISH method to detect CHIC2 deletion, FIP1L1/PDGFRA fusion and PDGFRA translocation in patients with myeloid neoplasms associated with eosinophilia. A total of 46 specimens were studied, including 15 from patients with a CHIC2 abnormality and six patients with an abnormality involving PDGFRA. Our results revealed this new FISH assay accurately detects these abnormalities and will be a useful clinical test for patients with myeloid neoplasms and eosinophilia.