Fig. 8

Kaplan-Meier survival estimates for NPC patients at different clinical stages according to two staging systems and stratified by subtypes according to the proposed classification. The OS differed significantly according to subtype of the proposed classification for patients at different clinical stages classified according to the 1992 China staging system (P = 0.031, a; P = 0.002, c; P < 0.001, e and g) and the 1997 AJCC staging system (all P < 0.001, d, f, and h), respectively. The log-rank test was used to calculate P values