Semi-quantitative scoring of potentially predictive markers for endocrine treatment of breast cancer: a comparison between whole sections and tissue microarrays.
OBJECTIVE
To assess whether immunohistochemically stained tissue microarrays (TMA) of 2 mm cores from paraffin embedded tumour tissue may replace whole sections in semi-quantitative evaluation of selected potential markers for endocrine treatment.


METHODS
Whole sections and 2 mm cores on TMA were used for immunohistochemical staining of potential markers for endocrine treatment. The Allred scoring system was used for the markers with nuclear localisation: the oestrogen receptor, the progesterone receptor, p27 and the oestrogen receptor co-regulator amplified in breast cancer 1 (AIB1). The Allred scoring system was also used for the non-nuclear markers Bcl-2, pS2 and cyclooxygenase 2 (COX-2); the membrane receptors HER-2, insulin-like growth factor I receptor (IGF-IR) and epidermal growth factor receptor were quantified according to the guidelines for the Herceptest.


RESULTS
The data and statistical analyses showed that the semi-quantitative evaluation of oestrogen receptor, progesterone receptor, AIB1, COX-2, HER-2 and IGF-IR on TMA blocks was comparable with analysis on whole sections.


CONCLUSIONS
This study shows that semi-quantitative scoring of 2 mm cores on TMA is feasible for several potential markers for endocrine therapy. Considering the small size of many breast tumours, the speed and cost-effectiveness of immunohistochemistry on TMA compared with whole sections, and the importance of the expression level of the proteins, semi-quantitative scoring on TMA has great potential in both retrospective and prospective studies aiming at improving the prediction of response to endocrine treatment.
Henriksen
Katrine L
KL
Department of Tumor Endocrinology, Institute of Cancer Biology, Danish Cancer Society, Copenhagen Ø, Denmark.
Rasmussen
Birgitte B
BB
Lykkesfeldt
Anne E
AE
Møller
Susann
S
Ejlertsen
Bent
B
Mouridsen
Henning T
HT
D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000737:chemistry* / Q000188:drug therapy; D002462:Cell Membrane / Q000737:chemistry; D002467:Cell Nucleus / Q000737:chemistry; D051546:Cyclooxygenase 2 / Q000032:analysis; D003593:Cytoplasm / Q000737:chemistry; D005260:Female; D051548:Histone Acetyltransferases / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D009363:Neoplasm Proteins / Q000032:analysis*; D056921:Nuclear Receptor Coactivator 3; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D017526:Receptor, IGF Type 1 / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D013048:Specimen Handling / Q000379:methods; D013629:Tamoxifen / Q000627:therapeutic use; D046888:Tissue Array Analysis / Q000379:methods; D015534:Trans-Activators / Q000032:analysis
D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D051546:Cyclooxygenase 2; D051548:Histone Acetyltransferases; D009363:Neoplasm Proteins; D056921:Nuclear Receptor Coactivator 3; D018719:Erb-b2 Receptor Tyrosine Kinases; D017526:Receptor, IGF Type 1; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D013629:Tamoxifen; D015534:Trans-Activators; C538866:NCOA3 protein, human