title: [Influence of level-Ib lymphadenopathy on the prognosis of nasopharyngeal carcinoma].
abstract: OBJECTIVE
  The level-Ib lymph node metastasis is rare in nasopharyngeal carcinoma (NPC). When and how this level should be irradiated with precise radiotherapy remains controversial. This study evaluated the prevalence and prognostic significance of level-Ib lymphadenopathy on the prognosis of NPC patients.
  
  
  METHODS
  From January 1990 and December 1999, 933 newly diagnosed patients with NPC treated at Sun Yat-sen University Cancer Center were randomly selected, examined with computed tomography (CT) imagining for evidence of level-Ib lymphadenopathy before treatment. All patients received radical radiotherapy with or without chemotherapy. The relationship between level-Ib lymphadenopathy and post-treatment outcomes including overall survival (OS), locoregional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were analyzed using Kaplan-Meier methods. The Cox proportional hazards regression model was used to adjust for other prognostic factors.
  
  
  RESULTS
  Of the 933 patients, 55 (5.9%) were found to have level-Ib lymphadenopathy, which was associated with carotid sheath involvement, oropharynx involvement and levels, and lateral cervical lymph node involvement. In the subgroup with carotid sheath involvement, with multivariate analysis accounting for all previously known prognostic factors, level-Ib lymphadenopathy was still associated with a risk of decreased OS (RR, 2.124; P<0.001), DMFS (RR, 2.168; P<0.001), and LRFS (RR, 1.989; P=0.001).
  
  
  CONCLUSIONS
  Level-Ib lymphadenopathy in the patients with carotid sheath involvement is an independent prognostic factor.
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, 510060, Guangdong, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yi
authors.forename: Xiao-Mao
authors.initials: XM
authors.lastname: Liu
authors.forename: Yun-Fei
authors.initials: YF
authors.lastname: Xia
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.forename: Jin-Tian
authors.initials: JT
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy; D017024:Chemotherapy, Adjuvant; D002648:Child; D003037:Cobalt Radioisotopes / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy; D009333:Neck / Q000473:pathology; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D010315:Particle Accelerators; D010614:Pharynx / Q000473:pathology; D011379:Prognosis; D016016:Proportional Hazards Models; D011859:Radiography; D011867:Radioisotope Teletherapy; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult
chemical_list: D003037:Cobalt Radioisotopes