Fig. 2

Overall survival (OS) and disease-free survival (DFS) after weighting by the Kaplan–Meier method. A The 5-year OS rate was significantly worse in the preoperative anemia group than in the non-anemia group (71.3% vs. 78.6%, p < 0.001). B The preoperative anemia was also associated with a significantly worse 5-year DFS (63.9% vs. 70.9%, p < 0.001)