*3.2. Univariate and Multivariate Survival Analysis*

The median DFS and OS of all patients were 449 and 991 days, respectively. In the analysis according to the epithelial histology, the median DFS and OS of patients with AC and non-AC components were 522 and 1038 days and 336 and 507 days, respectively. In total, 60 patients died, and recurrence after initial surgery was observed in 59 patients. The above survival information has been previously described [7–9]. The results of the survival analysis are listed in Table 2. The Kaplan-Meier survival curve of all patients with high or low GLUT1 expression is shown in Figure 3. According to the univariate analysis, disease stage and GLUT1 were identified as significant factors for predicting worse OS after surgery and disease stage; pleural invasion and GLUT1 displayed a close association with poor DFS. The different variables with a cut-off of *p* < 0.05 were screened based on the results of the univariate log-rank test. In all patients, the disease stage and GLUT1 were confirmed as independent prognostic factors related to worse OS and DFS by multivariate analysis. Next, we analyzed the prognostic significance of GLUT1 expression according to the epithelial histological types of PPC (AC and non-AC component). Figure 3 shows the Kaplan-Meier survival curve of patients with AC and non-AC components. In univariate analysis, patients with a non-AC component with high GLUT1 expression showed a significantly worse OS and DFS than low GLUT1 expression compared to those with an AC component.


**Table 2.** Univariate and multivariate survival analysis in all patients.

CI = confidence interval; \**p* < 0.05 is considered statistically significant, calculated with continuous variable; ly, lymphatic permeation; v, vascular invasion; pl, pleural invasion; GLUT1, glucose transporter 1; and HR, hazard ratio.

**Figure 3.** *Cont*.

**Figure 3.** Kaplan-Meier survival curves for all patients (**A**,**B**), those with adenocarcinoma (**C**,**D**), and those with nonadenocarcinoma (**E**,**F**). Patients with high GLUT1 expression exhibited a significantly worse OS (A) and DFS (B) than those with low GLUT1 expression. No significant difference in the OS (C) and DFS (D) was observed between patients with adenocarcinoma with high and low GLUT1 expression, whereas the OS (E) and DFS (F) in patients with nonadenocarcinoma were significantly lower in those with high GLUT1 expression than in those low GLUT1 expression.

Figure 4 shows the forest plot of the one-year OS and DFS rates according to GLUT1 expression for each variable. Patients with high GLUT1 expression exhibited a worse OS and DFS than those with low GLUT1 expression for different variables except for stages III and IV.

**B** 
