TY - JOUR
T1 - Effects of Slide Storage on Detection of Molecular Markers by IHC and FISH in Endometrial Cancer Tissues From a Clinical Trial
T2 - An NRG Oncology/GOG Pilot Study
AU - Grushko, Tatyana A.
AU - Filiaci, Virginia L.
AU - Montag, Anthony G.
AU - Apushkin, Marsha
AU - Gomez, Maria J.
AU - Monovich, Laura
AU - Ramirez, Nilsa C.
AU - Schwab, Carlton
AU - Kesterson, Joshua P.
AU - Seward, Shelly M.
AU - Method, Michael W.
AU - Olopade, Olufunmilayo I.
AU - Fleming, Gini F.
AU - Birrer, Michael J.
N1 - Funding Information:
Supported by National Cancer Institute grants K12CA139160 and CTSA-ITM (CS UL1 RR024999) to T.A.G., CA 27469 to the Gynecologic Oncology Group (GOG) Administrative Office, CA 37517 to the GOG Statistical Office, 1U10 CA180822 to NRG Oncology, U10CA180868 to NRG Oncology Operations, U10 CA27469, U24 CA114793, U10 CA180868 to the Gynecologic GOG Tissue Bank, and P30 CA14599 to the University of Chicago Cancer Center and IHC core facility. O.I.O. was supported by EIF NWCRA.
Publisher Copyright:
© 2021 Wolters Kluwer Health, Inc. All rights reserved.
PY - 2022/1/1
Y1 - 2022/1/1
N2 - We performed a pilot study in anticipation of using long-aged precut formalin-fixed paraffin-embedded tissue sections stored in real-world conditions for translational biomarker studies of topoisomerase 2A (TOP2A), Ki67, and human epidermal growth factor receptor 2 (HER2) in endometrial cancer. Formalin-fixed paraffin-embedded tissue blocks or unstained slides or both from GOG-0177 were collected centrally (1999-2000) and stored at room temperature. During 2004 to 2011 specimens were stored at 4°C. Matched pairs of stored slides and freshly cut slides from stored blocks were analyzed for TOP2A (KiS1), Ki67 (MIB1), and HER2 (HercepTest) proteins. To assess DNA stability (HER2 PathVision), fluorescence in situ hybridization (FISH) was repeated on stored slides from 21 cases previously shown to be HER2 amplified. Immunohistochemistry (IHC) staining intensity and extent, mean FISH copies/cell, and copy number ratios were compared using the κ statistic for concordance or signed rank test for differences in old cut versus new cut slides. IHC results reflected some protein degradation in stored slides. The proportion of cells with TOP2A staining was lower on average by 12% in older sections (P=0.03). The proportion of Ki67-positive cells was lower in stored slides by an average of 10% (P<0.01). Too few cases in the IHC cohort were FISH positive for any conclusions. HER2 amplification by FISH was unaffected by slide storage. We conclude that use of aged stored slides for proliferation markers TOP2A and Ki67 is feasible but may modestly underestimate true values in endometrial cancer. Pilot studies for particular storage conditions/durations/antigens to be used in translational studies are warranted.
AB - We performed a pilot study in anticipation of using long-aged precut formalin-fixed paraffin-embedded tissue sections stored in real-world conditions for translational biomarker studies of topoisomerase 2A (TOP2A), Ki67, and human epidermal growth factor receptor 2 (HER2) in endometrial cancer. Formalin-fixed paraffin-embedded tissue blocks or unstained slides or both from GOG-0177 were collected centrally (1999-2000) and stored at room temperature. During 2004 to 2011 specimens were stored at 4°C. Matched pairs of stored slides and freshly cut slides from stored blocks were analyzed for TOP2A (KiS1), Ki67 (MIB1), and HER2 (HercepTest) proteins. To assess DNA stability (HER2 PathVision), fluorescence in situ hybridization (FISH) was repeated on stored slides from 21 cases previously shown to be HER2 amplified. Immunohistochemistry (IHC) staining intensity and extent, mean FISH copies/cell, and copy number ratios were compared using the κ statistic for concordance or signed rank test for differences in old cut versus new cut slides. IHC results reflected some protein degradation in stored slides. The proportion of cells with TOP2A staining was lower on average by 12% in older sections (P=0.03). The proportion of Ki67-positive cells was lower in stored slides by an average of 10% (P<0.01). Too few cases in the IHC cohort were FISH positive for any conclusions. HER2 amplification by FISH was unaffected by slide storage. We conclude that use of aged stored slides for proliferation markers TOP2A and Ki67 is feasible but may modestly underestimate true values in endometrial cancer. Pilot studies for particular storage conditions/durations/antigens to be used in translational studies are warranted.
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U2 - 10.1097/PAI.0000000000000949
DO - 10.1097/PAI.0000000000000949
M3 - Article
C2 - 34224438
AN - SCOPUS:85122546278
SN - 1541-2016
VL - 30
SP - 27
EP - 35
JO - Applied Immunohistochemistry and Molecular Morphology
JF - Applied Immunohistochemistry and Molecular Morphology
IS - 1
ER -