title: The influence of nodal yield in neck dissections on lymph node ratio in head and neck cancer.
abstract: OBJECTIVE
  Recent studies suggest that lymph node ratio (LNR) is a strong prognostic factor in head and neck cancer. This study aims to determine if the yield of harvested lymph nodes (LNs) influences the LNR.
  
  
  METHODS
  The study included 522 head and neck cancer patients, undergoing 638 primary and salvage (selective) neck dissections between 2002 and 2012. Before 2007 the neck dissection specimens were macroscopically and microscopically examined by pathologists and after 2007 the macroscopic examination was performed by pathology technicians. For comparison of mean LN yields, univariate and multivariate analyses were performed.
  
  
  RESULTS
  The mean number of LNs among 374 specimens examined by pathologists was 24 (range 0-89) vs. 32 (range 2-89) among 264 specimens examined by pathology technicians (P<.001). This caused the mean LNR in the non pre-treated patient group to drop from 11.4% to 8.7%. The counts of LNs per type of neck dissection were significantly different and increased with the number of levels involved. However, there was no linear relationship and the higher yields could be mostly ascribed to LNs in level V. The LNR varied from 8.1% to 18.4% among the different types of neck dissections.
  
  
  CONCLUSIONS
  A significant increase in the number of harvested LNs, but a decrease in LNR was observed after introducing pathology technicians for macroscopic examination. A clear association between the extent of the dissection and the number of harvested LNs was observed. LNR appears to be strongly dependent on the harvesting protocol and the extent of the dissection.
authors.affiliation: Department of Head and Neck Oncology and Surgery, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: C C M
authors.initials: CC
authors.lastname: Marres
authors.affiliation: Department of Head and Neck Oncology and Surgery, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: de Ridder
authors.affiliation: Department of Pathology, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: I
authors.initials: I
authors.lastname: Hegger
authors.affiliation: Department of Pathology, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: M L F
authors.initials: ML
authors.lastname: van Velthuysen
authors.affiliation: Department of Epidemiology and Biostatistics, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Hauptmann
authors.affiliation: Department of Radiotherapy, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Navran
authors.affiliation: Department of Head and Neck Oncology and Surgery, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands. Electronic address: a.balm@nki.nl.
authors.forename: A J M
authors.initials: AJ
authors.lastname: Balm
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D005260:Female; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D006801:Humans; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged
keywords: Head and neck neoplasms; Lymph nodes; Lymphatic metastasis; Neck dissection; Pathology department