Fig. 3.

Survival curves for NPC patients with different factors. a, patients with the recurrent T category determined according to the American Joint Committee on Cancer (AJCC) staging system; b, patients stratified by the tumor volume; c, patients with the recurrent T category determined according to the proposed staging system (Tn*); d, receiver operator characteristic (ROC) curves for the recurrent T category alone, the tumor volume alone, and the addition of the tumor volume to the recurrent T category in the proposed staging system