Optimization of estrogen receptor analysis by immunocytochemistry in random periareolar fine-needle aspiration samples of breast tissue processed as thin-layer preparations.
Immunostaining of estrogen receptor alpha (ER) in samples of benign breast tissue obtained by random periareolar fine-needle aspiration (RPFNA) is a practical tool for breast cancer chemoprevention trials. The authors report an optimized method of ER immunostaining for use with thin-layer preparations of modified Cytolyt-fixed benign breast tissue acquired by RPFNA. Samples of benign breast tissue and MCF-7 controls processed as thin-layer preparations were tested for the effects of antibody titer, antigen retrieval temperature (90 degrees or 115 degrees C), buffer (20% nuclear decloaker, pH 9.3; 10 mM citrate buffer, pH 6), and blocking solution (0.01% glucose oxidase or 0.3% H2O2) on ER immunostaining. The prevalence of positively stained breast epithelial cells, mean intensity of ER staining, and composite immunostaining score were evaluated for effect of immunostaining protocol. RPFNA samples and MCF-7 cells processed using nuclear decloaker and low-temperature antigen retrieval had more ER-positive cells (P<0.0001) and increased mean staining intensity and weighted staining indices (P<0.05) compared with samples prepared with citrate buffer and high-temperature antigen retrieval. Glucose oxidase increased ER-positive cells in comparison to hydrogen peroxide (P<0.04) when combined with low-temperature antigen retrieval and the use of nuclear decloaker. Staining was negative for all non-immune controls regardless of protocol. The combination of low-temperature antigen retrieval, diluted commercial nuclear decloaker solution, and a glucose oxidase blocking step yielded optimal ER immunostaining for thin-layer preparations of benign breast tissue harvested by RPFNA.
Petroff
Brian K
BK
Breast Cancer Prevention Center, University of Kansas Medical Center, Kansas City, KS 66160, USA. bpetroff@kumc.edu
Clark
Julie L
JL
Metheny
Trina
T
Xue
Qiao
Q
Kimler
Bruce F
BF
Fabian
Carol J
CJ
D000906:Antibodies / Q000737:chemistry; D000941:Antigens / Q000276:immunology / Q000378:metabolism*; D044963:Biopsy, Fine-Needle; D001940:Breast / Q000473:pathology*; D045744:Cell Line, Tumor; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry / Q000592:standards*; D013194:Staining and Labeling / Q000592:standards*
D000906:Antibodies; D000941:Antigens; D047628:Estrogen Receptor alpha