Statistical analysis

Comparison of clinical characteristics between two groups was conducted with an unpaired Student's t-test, Wilcoxon rank sum test or χ² test. Comparison of the clinical and pathological responses between two groups was performed with Wilcoxon's rank sum test, the χ² test or Fisher's exact test as appropriate. Notably, in the PC group, there was a patient with PD who exhibited contralateral lymph node metastasis (as revealed by CT) after neoadjuvant treatment; based on a comprehensive evaluation conducted by the physician, it was decided that the patient was no longer suitable for surgery. Therefore, this patient only had clinical response data documented and was not included in the analysis of pathological response or survival. DFS and OS were calculated using the Kaplan-Meier method, and the comparison of DFS and OS between two groups was conducted using the log-rank test. The factors associated with MPR were analyzed with a multivariable logistic regression model, while the factors associated with DFS or OS were analyzed with the multivariable Cox's proportional hazards regression model. SPSS 22.0 (IBM Corp.) and GraphPad Prism 7.02 (GraphPad Software, Inc.) were applied for analysis and graphical representation of the data, respectively. P<0.05 was considered to indicate a statistically significant difference.