Polysomy 17 in HER-2/neu status elaboration in breast cancer: effect on daily practice
- PMID: 15958623
- DOI: 10.1158/1078-0432.CCR-04-2256
Polysomy 17 in HER-2/neu status elaboration in breast cancer: effect on daily practice
Abstract
Purpose: To assess the effect of chromosome 17 copy number on HER-2/neu status determination in breast cancers.
Experimental design: HER-2/neu gene copy and chromosome 17 centromere numbers were evaluated on 893 breast carcinomas using double color fluorescence in situ hybridization (FISH). The net and chromosome 17 corrected (ratio) HER-2/neu copy numbers were compared and related to immunohistochemistry done according to the Food and Drug Administration (FDA)-approved scoring system (0, 1+, 2+, and 3+) as a first screening step in 584 cases.
Results: When a ratio > or = 2 was considered as criterion for FISH positivity, 49.3% (440 of 893) of cases showed amplification versus 56.2% (502 of 893) by using a net HER-2/neu gene copy number >4 as a alternative criterion; 14.8% (67 of 453) of cases having a ratio <2 had a net HER-2/neu gene copy number >4 and 1.1% (5 of 440) with a ratio > or = 2 had a net HER-2/neu gene copy number <4. Among discordant cases, 88.8% (64 of 72) were polysomic (>2.25 chromosomes 17/cell) and among polysomic cases, 12.8% (40 of 312) of the low polysomic (2.26-3.75 chromosomes 17/cell) and 36.9% (24 of 65) of the highly polysomic (>3.75 chromosomes 17/cell) cases showed discordance. In cases with a ratio <2, polysomy 17 incidences were 85.7% (6 of 7) in IHC 3+, 42.4% (79 of 186) in IHC 2+, 33.3% (15 of 45) in IHC 1+, and 29.1% (16 of 55) in IHC 0.
Conclusion: A net increase in HER-2/neu gene copy number consecutive to polysomy 17 in the absence of specific gene amplification might lead to a strong protein overexpression in a small subset of breast carcinomas. HER-2/neu status determination by FISH is dependent on the criterion considered for positivity in clinical practice.
Similar articles
-
Aneusomy 17 in breast cancer: its role in HER-2/neu protein expression and implication for clinical assessment of HER-2/neu status.Mod Pathol. 2002 Feb;15(2):137-45. doi: 10.1038/modpathol.3880505. Mod Pathol. 2002. PMID: 11850542
-
The effect of chromosome 17 polysomy on HER-2/neu status in breast cancer.J Clin Pathol. 2008 Mar;61(3):317-21. doi: 10.1136/jcp.2007.050336. Epub 2007 Aug 30. J Clin Pathol. 2008. PMID: 17761736
-
Polysomy of chromosome 17 in breast cancer tumors showing an overexpression of ERBB2: a study of 175 cases using fluorescence in situ hybridization and immunohistochemistry.Breast Cancer Res. 2005;7(2):R267-73. doi: 10.1186/bcr996. Epub 2005 Jan 26. Breast Cancer Res. 2005. PMID: 15743507 Free PMC article.
-
Breast cancer in the 21st century: neu opportunities and neu challenges.Mod Pathol. 2001 Mar;14(3):213-8. doi: 10.1038/modpathol.3880288. Mod Pathol. 2001. PMID: 11266529 Review.
-
The clinical evaluation of HER-2 status: which test to use?J Pathol. 2003 Apr;199(4):411-7. doi: 10.1002/path.1354. J Pathol. 2003. PMID: 12635130 Review.
Cited by
-
Addition of Chromosome 17 Polysomy and HER2 Amplification Status Improves the Accuracy of Clinicopathological Factor-Based Progression Risk Stratification and Tumor Grading of Non-Muscle-Invasive Bladder Cancer.Cancers (Basel). 2022 Sep 21;14(19):4570. doi: 10.3390/cancers14194570. Cancers (Basel). 2022. PMID: 36230493 Free PMC article.
-
Clinicopathological Features of Breast Cancer with Polysomy 17 and Its Response to Neoadjuvant Chemotherapy.Eur J Breast Health. 2021 Mar 31;17(2):128-136. doi: 10.4274/ejbh.galenos.2021.2021-2-9. eCollection 2021 Apr. Eur J Breast Health. 2021. PMID: 33870112 Free PMC article.
-
HER2 status in breast cancer: changes in guidelines and complicating factors for interpretation.J Pathol Transl Med. 2020 Jan;54(1):34-44. doi: 10.4132/jptm.2019.11.03. Epub 2019 Nov 6. J Pathol Transl Med. 2020. PMID: 31693827 Free PMC article. Review.
-
Assessment of ERBB2 and TOP2α gene status and expression profile in feline mammary tumors: findings and guidelines.Aging (Albany NY). 2019 Jul 12;11(13):4688-4705. doi: 10.18632/aging.102079. Aging (Albany NY). 2019. PMID: 31301170 Free PMC article.
-
A model for the impact of FFPE section thickness on gene copy number measurement by FISH.Sci Rep. 2019 May 17;9(1):7518. doi: 10.1038/s41598-019-44015-7. Sci Rep. 2019. PMID: 31101839 Free PMC article.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Medical
Research Materials
Miscellaneous