The role of plasma Epstein-Barr virus DNA in the management of recurrent nasopharyngeal carcinoma.

OBJECTIVES/HYPOTHESIS: To study the role of plasma Epstein-Barr virus (EBV) DNA in patients with recurrent nasopharyngeal carcinoma (NPC) after previous chemoradiation.

STUDY DESIGN: Prospective.

METHODS: Sixty patients with recurrent NPC were recruited, and their plasma EBV DNA was checked preoperatively, 1 week postoperatively, and 6 months thereafter. In a pilot group of 30 patients, further testing was performed at 60 minutes after tumor resection. The plasma EBV DNA level was correlated with tumor T classification, resection margin status, and subsequent relapse.

RESULTS: The mean preoperative plasma EBV DNA reflected the tumor load (T1: 48 copies/mL, T2: 316 copies/mL, T3: 890 copies/mL, P = .03). It was significantly higher in patients with positive margins at the time of surgery (722 vs. 126 copies/mL, P = .02) and in those with subsequent systemic metastasis (668 vs. 92 copies/mL, P = .01). However, it failed to predict local recurrence after surgery. Postoperative plasma EBV DNA was undetectable in all patients with positive resection margins. Serial measurements were able to identify 87.5% of local recurrences and 100% of distance metastases.

CONCLUSIONS: In patients with recurrent NPC requiring salvage nasopharyngectomy, preoperative plasma EBV DNA identifies patients at high-risk of subsequent distant failure after surgery. Serial measurements of plasma EBV DNA after surgery, especially for those with high preoperative levels, is crucial to allow early detection of local of distant failure.