Assessment of HER-2/neu status in breast cancer using fluorescence in situ hybridization & immunohistochemistry: Experience of a tertiary cancer referral centre in India.
OBJECTIVE
Determination of HER2 status in breast cancer has become important to identify potential candidates for anti-HER2 therapy. In this study we compared fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) for the determination of HER2 status in breast cancer patients referred to a tertiary care referral centre.


METHODS
A total of 200 cases of invasive breast cancer were evaluated for HER2 status using IHC and FISH and results were compared.


RESULTS
The IHC 3+ (93.9%) and IHC negative (85.9%) cases showed good concordance with the corresponding FISH results; while 66.6 per cent of IHC 2+ cases showed gene amplification by FISH. In addition, hormone receptor expression and HER2 gene status showed a statistically significant inverse association (P<0.05).


CONCLUSIONS
These findings reaffirm IHC as a prudent first-step to screen tissue samples for HER2 status and to determine suitability for technically demanding FISH test and the dual coloured FISH as a gold standard for determination of HER2/neu status in IHC equivocal cases of breast carcinoma.
Panjwani
Poonam
P
Department of Pathology, Tata Memorial Hospital, Dr E. Borges Road, Mumbai, India.
Epari
Sridhar
S
Karpate
Arti
A
Shirsat
Hemlata
H
Rajsekharan
Preetha
P
Basak
Ranjan
R
Shet
Tanuja
T
Chinoy
Roshni
R
Chacko
Roy
R
Gursale
Sampada
S
Baraskar
Nayana
N
Gupta
Sudeep
S
Hawaldar
Rohini
R
Desai
Sangeeta
S
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007194:India; D008297:Male; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis* / Q000235:genetics; D012680:Sensitivity and Specificity
D015415:Biomarkers; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human