title: Extranodal extension and thickness of metastatic lymph node as a significant prognostic marker of recurrence and survival in head and neck squamous cell carcinoma.
abstract: OBJECTIVE
  We examined the effect of extranodal extension (ENE) and its thickness (ENET) of metastatic lymph node (LN) on the disease course of patients with head and neck squamous cell carcinoma.
  
  
  METHODS
  Data from 438 patients who were initially treated surgically at our center was retrospectively analyzed. ENE presence and ENET were examined in metastatic LN from each patient. Clinicopathologic characteristics, recurrence, and survival were then compared.
  
  
  RESULTS
  Of 438 patients, 219 (50%) showed positive nodal status, and ENE was identified in 84 (19.6%). Forty-five of 219 (20.5%) node-positive patients were classified with ENET ≥ 2 mm, which was associated with an increase in both the size and number of positive LN, bilateral cervical involvement, and a higher LN ratio. ENE-positive patients had a higher risk of recurrence and a lower overall survival rate; however, multivariate analysis failed to identify a significant difference in cancer-specific survival (CSS) between those with and those without ENE. On the contrary, ENET ≥ 2 mm was significantly associated with a poor CSS, even in multivariate analysis.
  
  
  CONCLUSIONS
  ENET ≥ 2 mm might be a complementary prognostic marker in CSS estimation for ENE positivity.
authors.affiliation: Department of Otorhinolaryngology, Gyeongsang National University Hospital, School of Medicine, Jinju, Republic of Korea.
authors.forename: Minsu
authors.initials: M
authors.lastname: Kwon
authors.affiliation: Departments of Otolaryngology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. Electronic address: rohjl@amc.seoul.kr.
authors.forename: Jong-Lyel
authors.initials: JL
authors.lastname: Roh
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Jungbok
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyung-Ja
authors.initials: KJ
authors.lastname: Cho
authors.affiliation: Departments of Otolaryngology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Seung-Ho
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Departments of Otolaryngology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Soon Yuhl
authors.initials: SY
authors.lastname: Nam
authors.affiliation: Departments of Otolaryngology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea; Biomedical Research Institute, Korea Institute of Science and Technology, Seoul, Republic of Korea.
authors.forename: Sang Yoon
authors.initials: SY
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking; D015992:Body Mass Index; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000556:secondary*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D020360:Neoadjuvant Therapy; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D012907:Smoking; D015996:Survival Rate; D055815:Young Adult
keywords: Extranodal extension; Head and neck cancer; Lymph node; Survival; Tumor thickness