Thirteen patients experienced grade 3–4 AEs and 26 patients did not. By univariate logistic regression analysis, high OPRT (accuracy 79.0%), high OPRT/DPD (80.8%), high OPRT/TP (77.8%), high OPRT/TS (71.0%), high OPRT/DPD + TP + TS (78.7%), high OPRT/DPD + TS (77.8%), high OPRT/TP + TS (77.2%), and high OPRT/DPD + TP (80.1%) were all associated with grade 3–4 AEs. OPRT/DPD exhibited the highest accuracy (80.8%). By multivariate logistic regression analysis, high OPRT/DPD [>0.754 vs. ≤0.754, OR 15.566 (1.490–162.605), P = 0.022] was independently predictive of grade 3–4 AEs. The rates of grade 3–4 AEs differed between patients with high OPRT/DPD and low OPRT/DPD (>0.754 vs. ≤0.754, 55.0 vs. 10.5%, P = 0.006). Figure 2b shows the ROC curve of OPRT/DPD for predicting grade 3–4 AEs.