Statistical thermodynamics of non-stoichiometric ceria and ceria zirconia solid solutions

The statistical mechanics of lattice configurations are used to develop an analytical model of non-stoichiometry in ceria and ceria zirconia.

Functional variants at the 11q13 risk locus for breast cancer regulate cyclin D1 expression through long-range enhancers

Analysis of 4,405 variants in 89,050 European subjects from 41 case-control studies identified three independent association signals for estrogen-receptor-positive tumors at 11q13. The strongest signal maps to a transcriptional enhancer element in which the G allele of the best candidate causative variant rs554219 increases risk of breast cancer, reduces both binding of ELK4 transcription factor and luciferase activity in reporter assays, and may be associated with low cyclin D1 protein levels in tumors. Another candidate variant, rs78540526, lies in the same enhancer element. Risk association signal 2, rs75915166, creates a GATA3 binding site within a silencer element. Chromatin conformation studies demonstrate that these enhancer and silencer elements interact with each other and with their likely target gene, CCND1.

Abstract P5-01-03: Discordant Estrogen and Progesterone Receptor Status in Breast Cancer

Introduction: Hormone receptor status is used to guide clinical therapy in breast cancer. Estrogen receptor (ER) assays from pathology reports have been shown to be in agreement with ER measured by a centralized laboratory on tissue microarray 87% of the time (Kappa = 0.64); however, little is known of reproducibility within subsets of patients defined by ER/PR status (1).

Methods: We computed percent agreement and Kappa statistics for ER/PR status as reported in pathology reports from Nurse's Health Study (NHS) participants with breast cancer from 1976 to 2000, and as scored by immunohistochemistry (IHC) on tissue microarrays at a central laboratory (n = 2011). Statistics were computed separately for 4 subsets of patients stratified by ER/PR status as defined by pathology reports (ER+/PR+, ER+/PR−, ER−/PR+, ER−/PR−). We also used a curated compilation of publicly available gene expression data sets providing both IHC and microarray data on ER and PR expression (n = 1236).

Results: We observed significant heterogeneity in Kappa values across the four groups of patients, with ER+/PR+ and ER−/PR- showing the strongest agreement, ER+/PR- showing fair agreement, and ER−/PR+ showing no significant agreement: 89.1% of ER+/PR+ cases from medical record were ER+/PR+ by TMA (κ=.60), 69.4% of ER−/PR- cases from medical record were ER−/PR- by TMA (κ=.63), 42% of ER+/PR- cases from medical record were ER+/PR- by TMA (κ=.37), and only 6% of cases of ER−/PR+ cases from medical record were ER−/PR+ by TMA (κ=.06). Using publicly available microarray data, we observed similar results comparing IHC to gene expression data in the same samples. Expression values were scaled across patients, and a patient was classified as positive for the marker by microarray if the scaled expression value was greater than zero. The agreement between IHC data and gene expression-based classification was 50.0% (k = .50), 80.8% (κ=.54), 42.0% (κ=.15), and 7.2% (κ = −.006) for ER+/PR+, ER−/PR−, ER+/PR−, and ER−/PR+, respectively.

Conclusion: ER−/PR+ is by far the most rare and least reproducible subset of breast cancer cases. Given the lack of reproducibility of the ER−/PR+ group and the minimal reported benefit from hormonal therapy in these patients (2), these data question the clinical utility of assessment of PR, particularly in ER− breast cancer.

1. Collins LC, Marotti JD, Baer HJ, Tamimi RM. Comparison of estrogen receptor results from pathology reports with results from central laboratory testing. Journal of the National Cancer Institute. 2008;100(3):218–21. 2. Anderson H, Hills M, Zabaglo L, A'Hern R, Leary AF, Haynes BP, et al. Relationship between estrogen receptor, progesterone receptor, HER-2 and Ki67 expression and efficacy of aromatase inhibitors in advanced breast cancer. Annals of oncology: official journal of the European Society for Medical Oncology/ESMO. 2011;22(8):1770–6.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-01-03.