RESUMEN
Objective:To investigate the prognosis of cervical and posterior to level V (PLV) lymph node metastasis and discuss further updates on neck levels and N stages for nasopharyngeal carcinoma (NPC). Methods:A total of 406 pathologically diagnosed NPC cases from December 2011 to June 2016 were retrospectively analyzed. SPSS 20.0 was used to analyze the prognosis of patients with cervi-cal and PLV lymph node metastasis. Results:In the 406 cases, the 5-year overall survival (OS), progression-free survival (PFS), local re-lapse-free survival (LRFS), and distant metastasis-free survival (DMFS) were 75.0%, 63.4%, 87.2%, and 81.8%, respectively. The 3-year OS, PFS, LRFS, and DMFS of patients with node involvement of PLV were 51.5%, 22.7%, 90.0%, and 41.3%, respectively. For the N3 stage, the 3-year OS, PFS, LRFS, and DMFS with or without PLV involvement were 43.9%and 84.7%(P=0.002), 12.9%and 55.4%(P=0.006), 88.9%and 80.3%(P=0.649), and 33.0%and 85.9%(P<0.001), respectively. Univariate analysis showed that N stage was a prog-nostic factor for OS, PFS, and DMFS (P<0.05). Multivariate analysis demonstrated that PLV was an independent prognostic factor for DMFS (P<0.05). Conclusion:Patients with NPC with PLV node involvement exhibited poor prognosis and an increased risk of distant metastasis. Thus, PLV should be a new neck node level for head and neck tumors.