title: A novel classification scheme for advanced laryngeal cancer midline involvement: implications for the contralateral neck.
abstract: OBJECTIVE
  There are insufficient data concerning risk factors for contralateral regional metastases in laryngeal cancer. The aim of this study was to investigate the frequency and risk factors for contralateral lymph node metastases and their dependence on midline involvement of the primary tumor in patients with advanced laryngeal squamous cell carcinoma.
  
  
  METHODS
  58 consecutive patients (8 females, 50 males; mean age 64.2 ± 9.8 years; AJCC stage III disease in 43.1%, IVA disease in 54.4%) undergoing primary total laryngectomy with bilateral neck dissection between 2002 and 2016 have been retrospectively investigated at one of the largest university medical centers in Europe. Preoperative staging computed tomography (CT) scans were analyzed for midline involvement of the primary laryngeal cancer. As a result, a classification scheme has been established (type A: clear, type B: involved, type C: exceeded, and type D: bilateral/origin side indeterminable).
  
  
  RESULTS
  Contralateral lymph node metastases (pN2c necks) were found in six cases (10.3%), from which four were diagnosed with type D (23.5% of type D cases), and one each with type B and type C midline involvement. In cases with no midline involvement (type A), a risk ratio reduction of 100% was seen. CT-based midline typing resulted in fourfold increased sensitivity for predicting contralateral metastases compared to conventional staging. Positive nodal status (pN+) significantly reduced overall and disease-free survival (HR 2.706, p < 0.05).
  
  
  CONCLUSIONS
  As a consequence, for type A category, a contralateral neck dissection might be avoidable accompanied by a reduction in surgical complications and operating time.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery and Oncology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany. ar.boettcher@uke.de.
authors.forename: Arne
authors.initials: A
authors.lastname: Böttcher
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Heidi
authors.initials: H
authors.lastname: Olze
authors.affiliation: Department of Radiology, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Thieme
authors.affiliation: Department of Radiation Oncology and Radiotherapy, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Carmen
authors.initials: C
authors.lastname: Stromberger
authors.affiliation: Clinical Cancer Registry, Charité Comprehensive Cancer Center, Charité-Universitätsmedizin Berlin, Campus Charité Mitte, Charitéplatz 1, 10117, Berlin, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Sander
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery and Oncology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
authors.forename: Adrian
authors.initials: A
authors.lastname: Münscher
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery and Oncology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Bier
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Knopke
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell; D018572:Disease-Free Survival; D005260:Female; D006258:Head and Neck Neoplasms; D006801:Humans; D007822:Laryngeal Neoplasms / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D007825:Laryngectomy / Q000379:methods*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009367:Neoplasm Staging; D057234:Preoperative Period; D012307:Risk Factors; D000077195:Squamous Cell Carcinoma of Head and Neck; D014055:Tomography, Emission-Computed
keywords: HNSCC; Laryngeal cancer; Laryngectomy; Midline involvement; Neck dissection; Regional metastases