Preoperative assessment of HER-2/neu status in breast carcinoma: the role of quantitative real-time PCR on core-biopsy specimens.
OBJECTIVE
Knowledge of HER-2/neu status is mandatory to identify breast cancer patients amenable to trastuzumab treatment. We evaluated the diagnostic performance of quantitative real-time polymerase chain reaction (qRT-PCR) in the preoperative determination of HER-2/neu status in breast cancer, using core biopsy material.


METHODS
In a prospective series, qRT-PCR was performed on fresh core biopsy specimens taken preoperatively in 87 patients with breast carcinoma. Cases with qRT-PCR ratio > or = 2.0 were considered to have HER-2/neu amplification. The results of RT-PCR analysis were compared with those of the standard immunohistochemistry (IHC) and Fluorescence in situ hybridization (FISH) methods. Cases with IHC 3+ or with IHC 2+ and FISH showing amplification were considered HER-2/neu positive. All other cases were considered HER-2/neu negative.


RESULTS
qRT-PCR showed HER-2/neu amplification in 13 cases (14.9%), while the standard IHC-FISH combined approach identified 17 HER-2/neu-positive cases (19.5%). Overall, there was concordance between methods in 83 of 87 patients (95.4%). The Spearman's rho correlation coefficient was 0.851; p<0.001. The diagnostic performance for preoperative diagnosis of HER-2/neu status using RT-PCR on core biopsy specimens as compared to standard approach was as follows: sensitivity 76.5%; specificity 100%; positive predictive value 100%; negative predictive value 94.6%.


CONCLUSIONS
Quantitative RT-PCR determination of HER-2/neu status from core biopsy specimens provided results comparable to those given by the standard IHC and FISH methods. The use of qRT-PCR on core biopsy material may represent a very useful and easy tool to enhance early identification of HER-2/neu-positive breast cancer patients who, possibly can benefit from trastuzumab treatment.
Susini
Tommaso
T
Department of Gynecology, Perinatology and Human Reproduction, University of Florence, Viale Morgagni, 85 - 50134, Firenze, Italy. tommaso.susini@unifi.it
Bussani
Cecilia
C
Marini
Giulia
G
Nori
Jacopo
J
Olivieri
Simone
S
Molino
Cecilia
C
Bianchi
Simonetta
S
Vezzosi
Vania
V
Paglierani
Milena
M
Giachi
Massimo
M
Borrani
Elena
E
Scarselli
Gianfranco
G
D001706:Biopsy / Q000379:methods; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000201:enzymology* / Q000235:genetics; D005260:Female; D005784:Gene Amplification; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D011446:Prospective Studies; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D014463:Ultrasonography
D018719:Erb-b2 Receptor Tyrosine Kinases