[252] Diagnostic Utility of SNAIL in Metaplastic Breast Carcinoma
A Nassar, TA Giorgadze, C Cohen. Mayo Clinic, Rochester, MN; Wayne State University, Detroit, MI; Emory University Hospital, Atlanta, GA
Background: Metaplastic breast carcinoma (MBC) is a rare subtype of breast cancer characterized by coexistence of carcinomatous and sarcomatous components. SNAIL is a nuclear transcription factor that is incriminated in the transition of epithelial to mesenchymal differentiation of breast cancer. Aberrant SNAIL expression results in loss of expression of the cell adhesion molecule E-cadherin, an event associated with changes in epithelial architecture and invasive growth. The aim of our study is to identify the use of SNAIL in addition to traditional immunohistochemical (IHC) in accurate classification of MBC.
Design: Retrospective review of 35 cases of MBC from January 1997 to September 2007 is performed. Clinicopathologic information is obtained. A control group of 26 spindle cell lesions (4 myofibroblastomas, 14 phyllodes tumors, 8 pseudoangiomatous stromal hyperplasias) were used. IHC study was performed, using SNAIL (polyclonal; 1/500; DAKO, Carpinteria, CA), p63, EGFR, OSCAR, and wide spectrum cytokeratin (WS-KER). Scoring used <1% as negative for all markers.
Results:
Clinicopathologic factors of MBC patients| Age | Range 32-90 | Mean age 62.7 | | Histologic grade | Low grade | 8 (22.9%) | | High grade | 27 (77.1%) | | Histologic subtypes | Spindle cell | 21 (60%) | | Mixed squamous and spindle cell | 5 (14.3%) | | Squamous | 4 (11.4%) | | Matrix-producing | 3 (8.6%) | | Adenosquamous | 2 (5.7%) | | Tumor diameter (cm) | Range 0.8-24 | Mean 5.0 | | Receptor Status | ER positive | 2 (5.7%) | | PR positive | 1 (2.8%) | | Her2 positive | 0 | | Lymph node status | Positive | 4 (12%) | | Negative | 31 (88%) | | Recurrence | Local | 3 (8.6%) | | Distant | 7 (20%) | | Disease free survival | 1 year | 72% | | 3 years | 55% |
Sensitivity, Specificity, Positive (PPV) and Negative (NPV) Predictive Values of the different immunomarkers (%)| Markers | Sensitivity | Specificity | PPV | NPV | | SNAIL (61) | 100 | 3.8 | 58.3 | 100 | | p63 (61) | 68.6 | 100 | 100 | 70.3 | | EGFR (61) | 100 | 19.2 | 62.5 | 100 | | OSCAR (61) | 85.7 | 92.3 | 93.8 | 82.8 | | WS-KER (61) | 77.1 | 100 | 100 | 76.4 |
Conclusions: MBC tend to be high grade, triple-negative (ER-, PR-, Her2-) carcinomas with few axillary lymph node metastases. SNAIL and EGFR are sensitive markers with low specificity for detecting MBC. p63 and WS-KER are more specific, with moderate sensitivity. OSCAR is both sensitive and specific. Therefore, a combination of p63, OSCAR and WS-KER are very useful in the work-up of MBC.
Category: Breast
Tuesday, March 10, 2009 1:00 PM
Poster Session IV # 35, Tuesday Afternoon
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