title: Prognostic value of lymph node density in high-grade salivary gland cancers.
abstract: BACKGROUND
  To investigate the role of lymph node density (LND) as an independent prognostic factor in high-grade salivary gland cancers.
  
  
  METHODS
  All 87 patients with high-grade salivary gland cancers underwent curative surgery combined with neck dissection and most of them received postoperative radiotherapy or chemoradiotherapy. LND was calculated as the ratio of positive lymph nodes to total lymph nodes harvested. Clinicopathologic variables associated with cancer-specific survival (CSS) and overall survival (OS) were identified by univariate and multivariate analyses using the Cox-proportional hazards model.
  
  
  RESULTS
  Salivary duct carcinoma was the most common tumor (54%), followed by carcinoma ex pleomorphic adenoma (22%), and others. The 5-year CSS and OS were 50.9% and 49.6%, respectively, during a median follow-up of 61 months. In univariate analysis, tumor site, pathologic nodal stage, overall tumor-node-metastasis (TNM) stage, primary tumor size > 3 cm, lymphovascular invasion, perineural invasion, extranodal extension, number of metastatic lymph nodes, and LND > 4.0 were significant prognostic factors for CSS and OS (P < 0.05 each). Tumor site, perineural invasion, and LND were independent prognostic factors for both CSS and OS in multivariate analysis (P < 0.01).
  
  
  CONCLUSIONS
  Our findings support the prognostic value of LND for high-grade salivary gland cancers.
authors: Departments of Otolaryngology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors: Hye Ran
authors: HR
authors: Hong
authors: Jong-Lyel
authors: JL
authors: Roh
authors: Kyung-Ja
authors: KJ
authors: Cho
authors: Seung-Ho
authors: SH
authors: Choi
authors: Soon Yuhl
authors: SY
authors: Nam
authors: Sang Yoon
authors: SY
authors: Kim
mesh_terms: D008949:Adenoma, Pleomorphic / Q000401:mortality / Q000473:pathology / Q000628:therapy; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000401:mortality / Q000473:pathology / Q000628:therapy; D059186:Chemoradiotherapy, Adjuvant; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009361:Neoplasm Invasiveness; D011379:Prognosis; D016016:Proportional Hazards Models; D018714:Radiotherapy, Adjuvant; D012468:Salivary Gland Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000628:therapy
keywords: high-grade; lymph node ratio; prognostic factor; salivary gland cancer; survival