The volume of retropharyngeal nodes predicts distant metastasis in patients with advanced nasopharyngeal carcinoma.

We investigated the effect of retropharyngeal nodal volumes (RNV) on distant metastasis in patients with advanced nasopharyngeal carcinoma (NPC). From February 2000 to June 2006, a total of 181 patients with biopsy-proven NPC, no distant metastasis, and available pre-treatment magnetic resonance imaging (MRI) were retrospectively reviewed. Most of the patients (95.6%) had stage III/IV diseases. The contour of retropharyngeal nodes ≥5mm was delineated on the axial slides of pre-treatment T2-weighted MRI without contrast enhancement. The RNV was calculated by the Eclipse™ treatment planning software. The primary end-points were subsequent distant failure rates and distant metastasis failure-free survival (DMFFS). The pre-treatment RNV in patients who developed distant failure was higher than in those without distant failure (P=0.0536). The distant failure rates between the patients with RNV > and ≤4.68cm(3) were 33.3% and 16.0%, respectively (P=0.0112). The rates of 7-year DMFFS in patients with RNV > and ≤4.68cm(3) were 66.4% and 83.5%, respectively (P=0.0043). Multivariate Cox analysis showed N-stage (P<0.001), gender (P=0.026), and RNV (P=0.088) were important predictors for DMFFS. We conclude that the RNV measured by MRI is a potential predictor of distant metastasis in patients with advanced NPC.

Plasma EBV DNA clearance rate as a novel prognostic marker for metastatic/recurrent nasopharyngeal carcinoma.

PURPOSE: To investigate the prognostic effect of the concentrations and clearance rates of plasma EBV DNA in metastatic/recurrent nasopharyngeal carcinoma (NPC). EXPERIMENTAL DESIGN: Thirty relapsed and four previously nontreated metastatic NPC patients were treated according to the consensus guidelines of the head and neck cancer team in our hospital (i.v. chemotherapy first, followed by local irradiation boost and oral maintenance chemotherapy where applicable). Multiple plasma samples were collected during the first month of chemotherapy. Circulating EBV DNA concentrations were measured by a real-time quantitative PCR. The half-life values (t(1/2)) of plasma EBV DNA clearance were calculated. The associations between clinical outcome and plasma EBV DNA assays were analyzed. RESULTS: Tumor response evaluated after 12 weeks of treatment showed 14 complete responses (41.2%), 12 partial responses (35.3%), 7 stable diseases (20.6%), and 1 progression disease (2.9%). The plasma EBV DNA concentrations have no significant effects on outcome prediction. The t(1/2) of plasma EBV DNA clearance ranged from 1.85 to 28.29 days (median, 3.99). Patients with a short t(1/2) of plasma EBV DNA clearance have significantly higher complete response rate and overall survival than those with long t(1/2). Multivariate analysis revealed a significant effect of the t(1/2) of plasma EBV DNA clearance on survival. CONCLUSIONS: The clearance rates of plasma EBV DNA during the first month of chemotherapy can predict tumor response and patient survival. Early change of chemotherapy regimen may be considered for patients with slow plasma EBV DNA clearance rate.