Elevated pretreatment platelet distribution width and platelet count predict poor prognosis in nasopharyngeal carcinoma

Background: Previous studies have demonstrated that platelets play a multifaceted role in cancer progression and metastasis. However, the value of platelet indices for predicting survival in nasopharyngeal carcinoma (NPC) patients remains unknown. The aim of this study was to evaluate the predictive significance of platelet indices in NPC cases. Materials and Methods: A total of 168 patients who were diagnosed with NPC between January 2011 and June 2012 were recruited. The optimal cut-off values for the platelet indices were determined using a receiver operating characteristic curve. The Kaplan-Meier method and Cox regression were used to evaluate the prognostic impact of the potential predictors. Results: Of the 168 patients, high platelet distribution width (PDW) and platelet count (PLT) levels were observed in 81 (48.21%) and 68 (40.48%) of the patients, respectively. An increased PDW was associated with the depth of invasion (T stage, P = 0.019), lymph node metastasis (N stage, P = 0.026), and clinical stage (P < 0.001). Moreover, the survival analysis showed that the overall survival of the patients with a PDW > 16.3 fL or platelet count > 266 x 10(9)/L was associated with a poorer prognosis (both P < 0.001). In the multivariate Cox regression model, the PDW (P < 0.001), PLT (P = 0.001), T stage (P < 0.001), N stage (P = 0.006), clinical stage (P = 0.005), and Epstein-Barr virus DNA (P = 0.039) were independent prognostic factors for the overall survival. Conclusions: The PDW and PLT are easily available via a routine blood test, and our study showed that the PDW and PLT could be prognostic predictors in NPC patients. However, further studies are required to confirm this conclusion.