Fine-needle aspiration for nucleic acid-ased molecular analyses in breast cancer.
BACKGROUND
With the widespread development of genomic analysis, an accurate and quick method for obtaining high-quality nucleic acids is needed. The objective of the current study was to evaluate the quality and potential use of material obtained from fine-needle aspiration cytology (FNAC).


METHODS
Ultrasound- or palpation-guided FNAC was performed in 124 consecutive patients who had nodular breast lesions. The authors evaluated the amount of messenger RNA (mRNA) obtained, its quality through the RNA Integrity (RIN) score, and the factors that influenced both. For malignant lesions, the authors attempted to correlate estrogen receptor 1 (ESR1) and HER-2 (c-erb-B2) mRNA expression measured by real-time quantitative polymerase chain reaction with estrogen receptor and HER-2 detection obtained by immunohistochemistry (IHC) and/or fluorescent in situ hybridization (FISH) on the surgical specimen.


RESULTS
The amount of mRNA obtained was >1 microg in 89.5% of 124 samples (43 benign lesions and 81 adenocarcinomas). Overall, 59.3% of samples yielded >1 microg RNA with a RIN score >6. The most significant predictors of quality and quantity of mRNA were the cytopathologist who sampled the tumors and a diagnosis of cancer versus benign lesion. The median ESR1 expression level, which was expressed as the polymerase chain reaction cycle threshold (CT) level minus the average 18S value (dct), was 17.7 dct in patients with estrogen receptor-negative tumors and 11.1 dct in patients with estrogen receptor-positive tumors. The median HER-2 expression level was 15.1 dct in patients with HER-2-negative tumors and 10.7 dct in patients with HER-2-positive tumors. mRNA expression was concordant with the IHC/FISH evaluation in 90.3% of patients for estrogen receptor status and in 98.5% of patients for HER-2 status.


CONCLUSIONS
In 70% of cases, FNAC of breast lesions in well trained hands allowed the extraction of mRNA suitable for gene expression analysis.
Uzan
Catherine
C
Research Translational Laboratory, Histocytopathology Unit, Gustave Roussy Institute, 39 rue Camille Desmoulins, Villejuif, France. catherine.uzan@igr.fr
Andre
Fabrice
F
Scott
Veronique
V
Laurent
Isabelle
I
Azria
Elie
E
Suciu
Voichita
V
Balleyguier
Corinne
C
Lacroix
Ludovic
L
Delaloge
Suzette
S
Vielh
Philippe
P
D000230:Adenocarcinoma / Q000175:diagnosis* / Q000235:genetics / Q000601:surgery; D044963:Biopsy, Fine-Needle; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000601:surgery; D047628:Estrogen Receptor alpha / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008875:Middle Aged; D012333:RNA, Messenger / Q000302:isolation & purification*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
D047628:Estrogen Receptor alpha; D012333:RNA, Messenger; D018719:Erb-b2 Receptor Tyrosine Kinases