ABSTRACT
CIC-rearranged sarcoma (CRS) is a group of high-grade undifferentiated small round cell sarcomas examined as a separate entity in the current WHO classification; since it shows more aggressive clinical behavior and distinct morphological and molecular features compared to Ewing sarcoma (ES). As CCNE1 expression is associated with tumor growth in CIC::DUX4 sarcomas, we aimed to demonstrate the value of cyclin E1 expression in CRS. Cyclin E1 immunohistochemistry and break-apart FISH for EWSR1 and CIC gene rearrangements were performed on 3-mm tissue microarrays composed of 40 small round cell tumors. Five cases were classified as CRS, whereas 22 were ES and 13 were unclassified (EWSR1-/CIC-). Among all three diagnostic groups, we found cyclin E1 expression level to be higher in CRS (80 %) and unclassified groups (61.5 %) compared to ES (4.5 %, p < 0.001). In addition, high cyclin E1 expression levels were associated with higher mean age at diagnosis, presence of atypical histology and myxoid stroma, low CD99 expression, and presence of metastasis at diagnosis. The sensitivity and specificity of high cyclin E1 expression in detecting non-ES cases were 95.5 % and 66.7 %, respectively. However, the correlation between cyclin E1 expression level and survival was not statistically significant. This is the first study that shows cyclin E1 immunohistochemical expression in EWSR1-negative undifferentiated small cell sarcomas, particularly CRS.
Subject(s)
Biomarkers, Tumor , Cyclin E , Gene Rearrangement , Oncogene Proteins , Repressor Proteins , Humans , Male , Oncogene Proteins/metabolism , Oncogene Proteins/genetics , Female , Adult , Cyclin E/metabolism , Cyclin E/genetics , Middle Aged , Adolescent , Biomarkers, Tumor/metabolism , Biomarkers, Tumor/genetics , Young Adult , Child , Repressor Proteins/metabolism , Repressor Proteins/genetics , Immunohistochemistry/methods , Sarcoma, Ewing/metabolism , Sarcoma, Ewing/pathology , Sarcoma, Ewing/genetics , Sarcoma/pathology , Sarcoma/metabolism , Sarcoma/genetics , Sarcoma/diagnosis , In Situ Hybridization, Fluorescence/methods , Aged , Child, Preschool , RNA-Binding Protein EWS/genetics , RNA-Binding Protein EWS/metabolism , Sarcoma, Small Cell/metabolism , Sarcoma, Small Cell/genetics , Sarcoma, Small Cell/pathology , Sarcoma, Small Cell/diagnosisABSTRACT
ABSTRACT: Metaplastic breast cancer is a rare and heterogeneous breast cancer group that encompasses both malign epithelial and mesenchymal tissue components. Squamous cell breast cancer (SCC) is one of the types of metaplastic breast cancer, and diagnosis is established when more than 90% of the malignant cells are of squamous cell origin. Squamous cell metaplastic breast carcinoma is considered an aggressive tumor because of the risk of distant metastases, and there are limited data on treatment patterns. In this study, we report patient characteristics and treatment results of one patient with bilateral metaplastic squamous cell breast cancer.