Toi et al. BMC Cancer 2010, 10:56 http://www.biomedcentral.com/1471-2407/10/56 Page 5 of 10 Figure 1 Relationship between ICH results and HER mark measures of HER2. (a) Screening IHC results correlated with HER2 expression. (b) Repeat IHC results, all patients (compare to Figure S1). Figure 2 Kaplan-Meier curve of OS by HER2 expression subgroup. inappropriate in subsequent multivariate analyses. As shown in Table 3, this parabolic relationship was also confirmed by the Cox regression analysis using the cate- gorized variable of H2T (compared with the reference subgroup having higher 50%-75% H2T, HR of the 25% highest = 0.25, p = 0.019, 95%CI: 0.08-0.77; HR of the 25%-50% = 0.79, p = 0.610, 95%CI: 0.32-1.97; HR of the 25% lowest = 0.12, p = 0.004, 95%CI: 0.03-0.51), which also shows that hormone receptor status (HR = 0.18, p = 0.014, 95%CI: 0.04-0.71) and brain metastases (HR = 0.07, p < 0.001, 95%CI: 0.02-0.24) were significant prog- nostic factors. Thus, the best multivariate model con- tained three variables, H2T, progesterone receptor status, and brain metastases. Dividing the cohort into high HER2-expressing (≥ the median value of H2T) and low HER2-expressing (< the