A meta-analysis on concordance between immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) to detect HER2 gene overexpression in breast cancer.
BACKGROUND
We performed this meta-analysis study to evaluate the concordance and discordance between immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) in detecting HER2 alteration in human breast cancer.


METHODS
As a meta-analysis, the present study evaluated the available data from previous studies on the HER2 gene detected by IHC and FISH. To indicate the meta-analysis results, a forest plot was used.


RESULTS
We identified 172 citations, for which our inclusion criteria were met by 18 articles, representing 6629 cases. The overall concordance and discordance rate between IHC staining with score 0/1+ and FISH for detection failure of HER2 expression was 96 and 4 %, respectively. The present study showed that the overall proportion of FISH positive and negative rate for IHC score 2+ for detection of HER2 expression was 36 and 64 %, respectively; and 91 and 9 % for 3+ IHC scores.


CONCLUSIONS
The results of this study show that IHC score 0/1+ and 3+ cannot be completely considered as negative and positive breast cancer test, respectively. Therefore, we suggest a valid and complementary test, the same as FISH, to explore HER2 expression.
Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Pour Sina Avenue, 14176-13151, Tehran, Iran. f.bahrein@tums.ac.ir.
Fatemeh
F
Bahreini
Department of Biostatistics and Epidemiology, Modeling of Noncommunicable Diseases Research Center, School of Public Health, Hamadan University of Medical Sciences, Shahid Fahmideh Street, P.O.Box 4171, 65155, Hamadan, Iran. soltanian@umsha.ac.ir.
Ali Reza
AR
Soltanian
Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Pour Sina Avenue, 14176-13151, Tehran, Iran. mehdipor@tums.ac.ir.
Parvin
P
Mehdipour
D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism*; D012680:Sensitivity and Specificity
D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human
Breast cancer; Fluorescence in situ hybridization; HER2; Immunohistochemistry; Meta-analysis