Deutscher et al. BMC Cancer 2010, 10:519 http://www.biomedcentral.com/1471-2407/10/519 Page 5 of 7 Table 1 Univariate Analyses of TF and Tn Expression in Women With an Abnormal (Atypia or Cancer) vs. a Benign Breast Biopsy All Subjects (N) Premenopausal (N) Postmenopausal (N) TF Tn TF Tn TF Tn Log10 Mean (SD) Median Geometric Mean (SD) Log10 Mean (SD) Median Geometric Mean (SD) Log10 Mean (SD) Median Geometric Mean (SD) Log10 Mean (SD) Median Geometric Mean (SD) Log10 Mean (SD) Median Geometric Mean (SD) Log10 Mean (SD) Median Geometric Mean (SD) Overall 124 .65 (.54) 1.87 8.55 (12.73) .59 (.50) 2.87 6.47 (9.52) 52 .71 (.54) 4.53 9.44 (12.48) .58 (.46) 3.25 5.51 (7.33) 72 .60 (.53) 1.61 7.91 (12.96) .59 (.53) 1.94 7.16 (10.83) Benign1 34 .46 (.48) 1.19 5.63 (12.3) .54 (.50) 1.29 5.77 (8.48) 18 .61 (.59) 1.66 9.6 (16.04) .48 (.49) .97 4.71 (7.32) 16 .29 (.21) 1.19 1.17 (1.03) .61 (.52) 1.47 6.96 (9.73) Abnormal1 90 .72 (.54) 4.20 9.65 (12.78) .60 (.50) 3.12 6.73 (9.92) 34 .76 (.52) 7.71 9.36 (10.4) .64 (.45) 3.70 5.94 (7.4) 56 .69 (.56) 2.44 9.83 (14.12) .58 (.54) 2.44 7.21 (11.21) P value2 .016 .015 .12 .51 .57 .62 .34 .27 .95 .24 .25 .57 .007 .014 .000 .88 .71 .94 1: Benign = normal and hyperplasia; Abnormal = atypical hyperplasia, ductal carcinoma in situ and invasive cancer. TF and Tn median results are in Abs/μL. 2: P value for Log10 and geometric means are based on the t-test; P value for medians are based on the Mann-Whitney-Wilcoxon test. Discussion TF was the more predictive of disease in the breast than Tn. Based on our earlier published work [5], we first performed an indirect immunoassay using commercially obtained TF and Tn antibodies. The antibodies used in our initial report were no longer available, and the indir- ect assay using the new antibodies yielded TF and Tn concentration results that were variable and with a large number of outlier values. We next compared results using indirect and direct TF and Tn immunoassays of the same ND samples that were analyzed in our pub- lished report. We found that the direct immunoassays for TF and Tn were more reliable than the indirect assays. We previously found that the expression of some ND cancer prediction markers varied based on whether the subject requiring surgery did or did not have PND [8]. We therefore determined if TF and Tn concentration differed based on whether the sample was PND or NAF. Since we did not identify a concentration difference, all analyses included both PND and NAF samples. In a study involving N-nitrosomethylurea induced rat mammary cancer, Tn was found to be a biomarker of precancer in both breast tissue and serum [9]. While Tn concentrations were highest among women with DCIS and second highest among women with atypia, differ- ences between risk groups were not significant. We can- not exclude the possibility that with a larger sample size we would have found an association. One might ask why Tn was not associated with breast cancer, as was observed in our earlier report. First, there was a difference in the ND sample populations between our published report and current analyses. The first study was a blinded analysis performed on banked NAF samples, comparing women with breast cancer to asymptomatic women as a no cancer control. In the current analysis, all samples were obtained from women requiring surgical biopsy to evaluate an abnormal