Receiver operating characteristic (ROC) curves for survival prediction with TNM classification alone (stages I–II and III–IV) or with the addition of pretreatment platelet count ( ≤300 × 10
/L and >300 × 10
/L) to TNM classification in the 2,626 patients with nasopharyngeal carcinoma. A, overall survival. B, locoregional recurrence–free survival. C, distant metastasis–free survival. The P value was the comparison of area under the curves (AUCs) between the addition of platelet count to TNM classification and TNM classification alone.