Fig. 4

Disease-specific survival (DSS) after salvage treatment for locoregional recurrence were shown in (a), and for lung metastatic recurrence were shown in (b). Kaplan-Meier method for creating each survival curve and Log-rank test for significance test between groups were adopted, respectively. Significance level of 0.05 was used for comparison of all groups, and the Bonferroni correction was adopted to determine the proper significance levels in multiple pairwise comparisons. * represents significant p value. Abbreviations: DSS; disease-specific survival, Tx; therapy, BSC; best supportive care