title: Plasma uric acid and tumor volume are highly predictive of outcome in nasopharyngeal carcinoma patients receiving intensity modulated radiotherapy.
abstract: BACKGROUND
  The combined predictive value of plasma uric acid and primary tumor volume in nasopharyngeal carcinoma (NPC) patients receiving intensity modulated radiation therapy (IMRT) has not yet been determined.
  
  
  METHODS
  In this retrospective study, plasma uric acid level was measured after treatment in 130 histologically-proven NPC patients treated with IMRT. Tumor volume was calculated from treatment planning CT scans. Overall (OS), progression-free (PFS) and distant metastasis-free (DMFS) survival were compared using Kaplan-Meier analysis and the log rank test, and Cox multivariate and univariate regression models were created.
  
  
  RESULTS
  Patients with a small tumor volume (<27 mL) had a significantly better DMFS, PFS and OS than patients with a large tumor volume. Patients with a high post-treatment plasma uric acid level (>301 μmol/L) had a better DMFS, PFS and OS than patients with a low post-treatment plasma uric acid level. Patients with a small tumor volume and high post-treatment plasma uric acid level had a favorable prognosis compared to patients with a large tumor volume and low post-treatment plasma uric acid level (7-year overall OS, 100% vs. 48.7%, P <0.001 and PFS, 100% vs. 69.5%, P <0.001).
  
  
  CONCLUSIONS
  Post-treatment plasma uric acid level and pre-treatment tumor volume have predictive value for outcome in NPC patients receiving IMRT. NPC patients with a large tumor volume and low post-treatment plasma uric acid level may benefit from additional aggressive treatment after IMRT.
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangdong Province, Guangzhou 510060, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Lin
authors.forename: Huan-Xin
authors.initials: HX
authors.lastname: Lin
authors.forename: Nan
authors.initials: N
authors.lastname: Ge
authors.forename: Hong-Zhi
authors.initials: HZ
authors.lastname: Wang
authors.forename: Rui
authors.initials: R
authors.lastname: Sun
authors.forename: Wei-Han
authors.initials: WH
authors.lastname: Hu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood; D002277:Carcinoma; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000097:blood* / Q000473:pathology / Q000532:radiotherapy*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D050397:Radiotherapy, Intensity-Modulated; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden; D014527:Uric Acid / Q000097:blood*; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D014527:Uric Acid