Influence of slide aging on results of translational research studies using immunohistochemistry.
Author(s): Mirlacher M, Kasper M, Storz M, Knecht Y, Dürmüller U, Simon R, Mihatsch MJ, Sauter G
Publication: Mod Pathol, 2004, Vol. 17, Page 1414-20
PubMed ID: 15205686 PubMed Review Paper? No
Purpose of Paper
This paper explored potential effects of slide storage on immunohistochemical staining of clinically relevant markers of breast cancer (estrogen receptor, ER; progesterone receptor, PR; cyclin D1; human epidermal growth factor 2, HER2; E-cadherin) using a tissue microarray.
Conclusion of Paper
The percentage of specimens with a positive status was significantly higher in FFPE slide-mounted TMA sections stored for one week at room temperature than those stored for six months at 4°C for ER (65 vs. 46%, p<0.0001), PR (33 vs. 18.5%, p<0.0001), HER2 (16.3 vs. 9.6%, p=0.0047), and E-cadherin (58.9 vs. 32.9%, p<0.0001), while the difference was nonsignificant for cyclin D1 (45.1 vs. 37.7%, p=0.10). Despite reductions in immunostaining, associations between status and tumor grade were unchanged by slide storage for six months at 4°C. However, the significant associations between prognosis and HER2 (p=0.0195), ER (p=0.0120), and PR (p=0.023) status observed using slides stored for one week were lost for ER (p=0.1113) and PR (p=0.1428) in slides stored for six months at 4°C.
Studies
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Study Purpose
This study explored potential effects of slide storage on immunohistochemical staining of clinically relevant markers of breast cancer (estrogen receptor, ER; progesterone receptor, PR; cyclin D1; human epidermal growth factor receptor 2, HER2; E-cadherin). Two slides were created from a tissue microarray containing samples of 522 formalin-fixed paraffin-embedded (FFPE) breast carcinoma specimens. One slide was stored for one week at room temperature while the other was stored for six months at 4°C prior to analysis by immunohistochemistry. While all 522 specimens were analyzed for ER, PR, and HER2; analysis of cyclin D1 and E-cadherin staining was limited to 306 specimens due to mechanical damage to a portion of the TMA slide. Immunostaining was scored by a single pathologist who was blind to the experimental design.
Summary of Findings:
The percentage of specimens with a positive status was significantly higher in FFPE slide-mounted TMA sections stored for one week at room temperature than those stored for six months at 4°C for ER (65 vs. 46%, p<0.0001), PR (33 vs. 18.5%, p<0.0001), HER2 (16.3 vs. 9.6%, p=0.0047), and E-cadherin (58.9 vs. 32.9%, p<0.0001), while the difference was nonsignificant for cyclin D1 (45.1 vs. 37.7%, p=0.10). The authors noted that the intensity of immunostaining was also reduced in stored slides, but data was not shown. Despite reductions in immunostaining, associations between status and tumor grade were unchanged by slide storage for six months at 4°C. However, the significant associations between prognosis and HER2 (p=0.0195), ER (p=0.0120), and PR (p=0.023) status observed using slides stored for one week were lost for ER (p=0.1113) and PR (p=0.1428) in slides stored for 6 months at 4°C.
Biospecimens
Preservative Types
- Formalin
Diagnoses:
- Neoplastic - Carcinoma
Platform:
Analyte Technology Platform Protein Tissue microarray Protein Immunohistochemistry Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Storage duration 1 week
6 months
Immunohistochemistry Specific Targeted peptide/protein ER
PR
HER2
E-cadherin
Cyclin D1
Storage Storage temperature Room temperature
4°C