Simultaneous Fluorescence Immunophenotyping and Her-2/neu Genotyping (FICTION) in Breast Carcinoma Candidates to Target Therapy

Abstract

The study of proto-oncogene Her-2/neu using the fluorescence in situ hybridization (FISH) technique in routinely paraffin-embedded formalin-fixed tissue has become commonplace over the past decade and mandatory among invasive breast cancer expressing a score 2+ by immunohistochemical analysis of c-erbB2 protein. The patient's eligibility for treatment with the biological drug trastuzumab/herceptin is based on the evidence of a Her-2/neu proto-oncogene amplification (ratio Her-2/neu/CEP-17>2.2). However, although the exclusion is declared in the absence of Her-2/neu gene amplification (ratio Her-2/neu/CEP-17 <1.8) according to the American Society of Clinical Oncology/College of American Pathologists recommendations, there are borderline cases (1.8<ratio Her-2/neu/CEP-17>2.2) that need to be investigated (eg, ductal carcinoma in situ with microinvasion, metastatic breast cancer). In such cases with Her-2/neu genetic heterogeneity it is difficult to count the nuclear signals in the areas of invasive tumor using fluorescence. The availability of a Fluorescence Immunophenotyping and Interphase Cytogenetics as a Tool for Investigation of Neoplasms technique, based on the simultaneous evaluation of immunostaining with anticytokeratins (CKAE1/AE3 and CK19), together with FISH for Her-2/neu gene status [it is therefore useful and of current applicability in breast cancer blocks (formalin-fixed and paraffin-embedded)], permits a more easy identification of even single neoplastic cells by immunofluorescence and then a better evaluation of Her-2/neu status gene by the FISH technique, as shown in our study.

ImmunoFISH Is a Reliable Technique for the Assessment of 1p and 19q Status in Oligodendrogliomas

“…This technique called ImmunoFISH (ImFISH) was first described in the literature in the 90 s and was originally developed for the study of hematologic malignancies [51], [52], [53]. Its use has since been extended to other neoplastic processes including those of nerve [54], breast [55], prostate [56] and the gastrointestinal tract [57].…”

The t(14;18) translocation is absent from endothelial and follicular dendritic cells of follicular lymphoma (FL) and shows heterogeneous presence in preserved FL mantle zones

“…Using the FICTION approach we were able to simultaneously identify the lineage of the respective cells by fluorescence immunohistochemistry and the presence of a break in the BCL2 gene locus, indicative for a t(14;18) by fluorescence in situ hybridization (FISH) [ 10 , 11 ]. FICTION is a powerful technique [ 12 – 14 ], which has been used extensively in haematopoietic malignancies, e.g. to identify BCL6 imbalances in nodular lymphocyte predominant Hodgkin lymphoma [ 15 ] or 14q32 chromosomal rearrangements in multiple myeloma [ 16 ].…”

ALK-Positive Inflammatory Myofibroblastic Tumor of the Abdomen With Widespread Microscopic Multifocality

“…In addition, the fusion probe for ALK-EML4 t(2;2); inv(2) was used (Kreatech, Amsterdam, Netherlands). To identify tumor cells during FISH analysis applied on submesothelial tumor foci containing rare spindle cells, the FICTION technique was performed as previously reported, 10 combining ALK immunostain and FISH break-apart analysis.…”