## 3 Results
### Overall Survival Analysis According to the Combined Biomarker Expression  
Following the establishment of the significance of the investigated factors as single prognostic markers, we also examined the effect of their combined expression on OS in both our cohort and the TCGA cohort. Kaplan-Meier analysis revealed that the worst OS was observed in patients whose PDACs co-expressed SATB1\({}^{\text{c-present}}\)SMAD3\({}^{\text{high}}\)Ezrin\({}^{\text{high}}\)\(\beta\)-catenin\({}^{\text{high}}\). In turn, patients whose PDACs had opposite expression profiles of these proteins had significantly longer OS (8 vs. 1160 days; \(p\) = 0.001; Figure 6B). In univariate (HR 3.06, 95% CI 1.27-7.36, \(p\) = 0.01; Table 7B) and multivariate (HR 7.32, 95% CI 2.05-26.21, \(p\) = 0.002; Table 8B) analyses, the combined SATB1\({}^{\text{c-present}}\)SMAD3\({}^{\text{high}}\)Ezrin\({}^{\text{high}}\)\(\beta\)-catenin\({}^{\text{high}}\) was a significant poor prognostic factor for OS with a particularly high hazard ratio when compared to each marker as a single indicator. Furthermore, SATB1\({}^{\text{n}}\)/SMAD3/Ezrin/\(\beta\)-catenin expression panel was significantly related to the duration of OS, with patients in the SATB1\({}^{\text{n-high}}\)SMAD3\({}^{\text{low}}\)Ezrin\({}^{\text{low}}\)\(\beta\)-catenin\({}^{\text{low}}\) expression group experiencing the longest survival (median overall survival not reached), whereas the opposite pattern of the expression panel predicted a poor survival (118 days, \(p\) = 0.023; Figure 6A). The SATB1\({}^{\text{n-high}}\)SMAD3\({}^{\text{low}}\)Ezrin\({}^{\text{low}}\)\(\beta\)-catenin\({}^{\text{low}}\) expression group was associated with a reduced risk of death by 89% after adjusting for age, tumor stage and LVI (HR 0.11, 95% CI 0.01-0.93, \(p\) = 0.004; Table 8A). In turn, in univariate and multivariate analysis, the crude and adjusted HRs were 2.16 (95% CI 1.03-4.52, \(p\) = 0.04) and 2.91 (95% CI 1.07-7.91, \(p\) = 0.04), respectively, for SATB1\({}^{\text{n-low}}\)/SMAD3\({}^{\text{high}}\)/Ezrin\({}^{\text{high}}\)/\(\beta\)-catenin\({}^{\text{high}}\) expression group (Tables 7A and 8A). \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Variable**} & \multirow{2}{*}{**HR**} & \multicolumn{4}{c}{**95\% CI**} & \multirow{2}{*}{\(p\) **Value**} & \multirow{2}{*}{**Variable**} & \multirow{2}{*}{**HR**} & \multicolumn{2}{c}{**95\% CI**} & \multirow{2}{*}{\(p\) **Value**} \\ \cline{3-3} \cline{5-10}  & & & **Lower** & & **Upper** & & & **Lower** & **Upper** \\ \hline SATB1 & 0.50 & 0.32 & 0.78 & **0.002** & SMAD3 & 1.57 & 0.99 & 2.49 & **0.05** \\ \hline age & 1.02 & 1.00 & 1.04 & 0.09 & age & 1.02 & 1.00 & 1.04 & **0.04** \\ \hline grade & 1.76 & 0.92 & 3.37 & 0.09 & grade & 1.51 & 0.79 & 2.89 & 0.21 \\ \hline pN & 2.53 & 1.42 & 4.52 & **0.0016** & pN & 1.77 & 1.02 & 3.09 & **0.04** \\ \hline pT & 1.32 & 0.64 & 2.72 & 0.46 & pT & 1.43 & 0.70 & 2.92 & 0.32 \\ \hline \multirow{2}{*}{**Variable**} & \multirow{2}{*}{**HR**} & \multicolumn{4}{c}{**95\% CI**} & \multirow{2}{*}{\(p\) **Value**} & \multirow{2}{*}{**Variable**} & \multirow{2}{*}{**HR**} & \multicolumn{2}{c}{**95\% CI**} & \multirow{2}{*}{\(p\) **Value**} \\ \cline{3-3} \cline{5-10}  & & & **Lower** & & **Upper** & & & **Lower** & **Upper** \\ \hline EZR & 2.50 & 1.07 & 5.83 & **0.033** & CTNNB1 & 1.42 & 0.83 & 2.45 & 0.20 \\ \hline age & 1.02 & 1.00 & 1.04 & **0.05** & age & 1.02 & 1.00 & 1.04 & **0.04** \\ \hline grade & 1.43 & 0.75 & 2.74 & 0.28 & grade & 1.54 & 0.81 & 2.94 & 0.19 \\ \hline pN & 1.83 & 1.06 & 3.17 & **0.030** & pN & 1.76 &