ABSTRACT
Myxoid liposarcoma (MLPS) has different patterns that are often difficult to distinguish from other soft tissue lesions. MLPS is characterized by a reciprocal translocation involving the DNA Damage Inducible Transcript 3 gene (DDIT3) that can be detected using fluorescent in situ hybridization (FISH). Recently, the marker for cancer testis antigen 1b (CTAG1B) was found to be expressed in MLPS. The aim of the present study was to assess the potential use immunohistochemistry (IHC) for CTAG1B expression and DDIT3 rearrangement to diagnose MLPS and distinguish it from similar lesions. Out of 29 cases including MLPS and its mimics, CTAG1B was expressed in 92.86% of cases of MLPS and 20% of its mimics. DDIT3 rearrangement was 100% sensitive and 92.86% specific in distinguishing MLPS from its mimics. The DDIT3 rearrangement was found to be more sensitive but less specific than cytoplasmic expression of CTAG1B marker. DDIT3 polysomy and amplification were detected in some cases. Therefore, both CTAG1B expression and FISH for DDIT3 gene can be used to distinguish MLPS from similar tumors. The use of both immunohistochemistry for CTAG1B in addition to DDIT3 gene rearrangement detection by FISH was more specific than using either of them alone. However, the DDIT3 gene rearrangement alone was the most sensitive test for distinguishing MLPS from its mimics.
Subject(s)
Liposarcoma, Myxoid , Soft Tissue Neoplasms , Antigens, Neoplasm , Clone Cells/pathology , DNA Copy Number Variations , Gene Dosage , Gene Rearrangement/genetics , Humans , In Situ Hybridization, Fluorescence , Liposarcoma, Myxoid/diagnosis , Liposarcoma, Myxoid/genetics , Liposarcoma, Myxoid/pathology , Male , Membrane Proteins/genetics , Soft Tissue Neoplasms/diagnosis , Soft Tissue Neoplasms/genetics , Soft Tissue Neoplasms/pathology , Transcription Factor CHOP/geneticsABSTRACT
BACKGROUND: HER-2 and TOP2A genes are considered of great importance in breast cancer. Their copy number variability has been proposed to be a marker for the degree of chromosomal instability. Owing to the close proximity of TOP2A gene to HER-2 gene chromosome 17, TOP2A status is believed to affect therapeutic plan. The percentage of TOP2A aberrations is greatly variable among different studies. AIM OF WORK: Is to investigate the relation between TOP2A and HER-2 gene amplification using fluorescence in situ hybridization technique. MATERIALS AND METHODS: Archival blocks of 112 breast cancer Egyptian female patients were retrieved from the pathology department at NCI, Cairo University were retrieved and investigated using fluorescence in situ hybridization technique for TOP2A and HER-2 gene assessment. In addition, correlation with some clinicopathologic parameters was done. RESULTS: HER-2 gene amplification was encountered in about 33% of cases. TOP2A gene amplification and deletion were detected in 23.9% and 2.8% of studied cases. Moderate agreement was obtained between results of HER-2 gene and TOP2A gene amplification. CONCLUSIONS: HER-2 and TOP2A genes amplification are 2 separate genetic yet closely related events in breast cancer. Polysomy of chromosome 17 is proposed to be an early event in occurrence of TOP2A gene amplification. Further studies regarding effect of TOP2A gene in response to anthracyclines in Egyptian population should be planned for to establish its role in therapeutic planning.
Subject(s)
Breast Neoplasms , Chromosomes, Human, Pair 17 , DNA Topoisomerases, Type II , Gene Amplification , In Situ Hybridization, Fluorescence , Poly-ADP-Ribose Binding Proteins , Receptor, ErbB-2 , Adult , Aged , Aged, 80 and over , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Chromosomes, Human, Pair 17/genetics , Chromosomes, Human, Pair 17/metabolism , DNA Topoisomerases, Type II/genetics , DNA Topoisomerases, Type II/metabolism , Egypt , Female , Humans , Middle Aged , Poly-ADP-Ribose Binding Proteins/genetics , Poly-ADP-Ribose Binding Proteins/metabolism , Receptor, ErbB-2/genetics , Receptor, ErbB-2/metabolism , Retrospective StudiesABSTRACT
BACKGROUND: Breast cancer is a major health problem in Egypt. Her-2/Neu gene is routinely assessed for all breast cancer patients primarily by immunohistochemistry. At National Cancer Institute (NCI), Cairo University, Flourescence In Situ hybridization (FISH) analysis of Her-2/Neu gene is carried out for Her-2/Neu score 2 and for some cases of score 3 (particularly those assessed outside NCI). The test is performed essentially on the primary tumor. However, some situations require testing on corresponding lymph node metastases. There is a debate about the concordance between Her-2/Neu status in the primary tumor and synchronous lymph node metastases in various studies. AIM OF THE STUDY: The aim of this study was to test for the concordance between Her-2/Neu status in the primary breast tumor and corresponding axillary nodal metastases. MATERIALS AND METHODS: This is a retrospective study in which FISH analysis of Her-2/Neu was carried out simultaneously on archived material of 50 cases previously diagnosed as invasive duct carcinoma and the corresponding nodal metastases from the Pathology Department, NCI. RESULTS: There was complete concordance between Her-2 status in the primary tumor and the corresponding axillary lymph node metastatic deposits in which Her-2 was amplified in 44% of the studied cohort of Egyptian patients. CONCLUSIONS: Her-2/Neu gene assessed by FISH analysis on synchronous lymph node metastases is strongly correlated with the primary tumor. Hence, it is justified to carry out the Her-2/Neu test on synchronous lymph nodes to decide on whether to carry out anti-Her-2/Neu target therapy. Further studies on other metastatic sites is recommended.
