[280] Novel Non-Biotin Polymeric Immunohistochemical Visualization Systems Improve Estrogen Receptor Evaluation in Breast Cancer

RM Rocha, K Miller, NG Moraes, J Vassallo, FA Soares, H Gobbi. University College London, London, United Kingdom; Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Universidade Estadual de Campinas, Campinas, Brazil; Universidade Estadual de Sao Paulo, Sao Paulo, Brazil

Background: A novel generation of immunohistochemical (IHC) visualization systems based on a non-biotin polymeric (NBP) technology has been released recently. We compared the new NBP and the streptavidin-biotin systems (SAB) to evaluate estrogen receptor (ER) in breast carcinomas.
Design: Serial sections from a tissue microarray (TMA) containing 320 invasive breast carcinomas were marked for ER using the rabbit monoclonal antibody SP1. Eleven different visualization systems were used, including 7 NBP and 4 SAB following the instructions provided by the suppliers. All slides were scanned using Mirax Scan, Zeiss, and the intensity of IHC staining was automated quantified using HistoQuant software. The background was visually evaluated as absent (0), weak (1), moderate (2), or strong (3).
Results: NBP Advance and Novolink, and the SAB LSAB+ showed the strongest staining intensity (P<0.01). Advance also showed 2 positive cases that were considered negative when manually evaluated with all the other systems. The seven NBP showed no background and sharper staining when compared to SAB systems (p<0.05). NBP PicTureMAX, showed the least background and SAB LSAB+ showed the most.

Comparison of eleven different visualization systems grouped according their staining intensity level expressed by the p value

Staining intensity level	Non-biotin polymer system (p value*)	Streptavidin-biotin polymer (p value*)
Stronger	Advance (0.0034) / NovoLink (0.0061)	LSAB+ (0.03)
Up intermediate	Super Sensitive non-biotin HRP (0.01) / PicTure Max (0.01)	Super Sensitive (0.02)
Low intermediate	Super PicTure (0.01) / Mouse or rabbit Polydetector (0.01)	Mouse or rabbit Immunodetector / EasyPath
Weaker	EnVision+	----------

* p value of the statistical analysis between the staining intensity of each visualization system and the group of systems from the level below.


Conclusions: The NBP provide sharper IHC signal without background. The NBP Advance and Novolink, followed by all the other 2^nd generation NBP, represent a powerful tool for reliable standardization of IHC for ER evaluation in breast carcinomas.
Category: Breast

Wednesday, March 11, 2009 9:30 AM

Poster Session V # 10, Wednesday Morning