title: Prognostic value of sentinel lymph node biopsy in 121 low-risk melanomas (tumour thickness <1.00 mm) on the basis of a long-term follow-up.
abstract: OBJECTIVE
  Sentinel lymph node biopsy (SLNB) is a widely accepted procedure to accurately stage melanomas with a thickness ≥1 mm. The value of SLNB in thin melanomas is still controversial, especially because long-term observations of these patients are rare. The purpose of the current study was to identify the positive sentinel lymph node (SLN) ratio in low-risk patients with cutaneous melanoma (CM) of thickness less than 1 mm and its possible prognostic value, focusing on long-term follow-up data.
  
  
  METHODS
  In a retrospective single-centre study performed at the Department of Dermatology and Allergy, University of Bonn, 121 patients who had received SLNB were identified out of 621 patients with a diagnosis of CM of <1.00 mm thickness presenting between September 2000 and February 2009 (mean follow-up time, 50.9 months).
  
  
  RESULTS
  Of the 121 patients, 5 (4.1%) had a positive SLN. All positive SLNs were found in patients with a tumour thickness between 0.90 mm and 1.00 mm. There were no significant differences in the presence of positive SLNs according to Clark level and ulceration status (Clark levels II and III and no ulceration vs. Clark levels IV and V or ulceration), regression, gender or age. Disease-free survival was 100% in the SLN-positive patients. On the other hand, five SLN-negative patients (4.1%) developed disease progression. One of these five progressive patients showed recurrence in the former negative SLN basin (16.7% false-negative rate).
  
  
  CONCLUSIONS
  A positive SLN in thin melanomas is uncommon with a prevalence of 4.1% in our study population. We could not identify reliable clinicopathological risk factors which could predict results of SLNB in thin melanomas. Based on our results, SLNB may be considered in patients with a melanoma of thickness in the range 0.90-0.99 mm, because all SLN-positive patients belonged to this subgroup.
authors.affiliation: Department of Dermatology and Allergology, Center of Integrated Oncology (CIO) Cologne Bonn, University of Bonn, Bonn, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Hinz
authors.forename: Hojjat
authors.initials: H
authors.lastname: Ahmadzadehfar
authors.forename: Anja
authors.initials: A
authors.lastname: Wierzbicki
authors.forename: Tobias
authors.initials: T
authors.lastname: Höller
authors.forename: Jörg
authors.initials: J
authors.lastname: Wenzel
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Biersack
authors.forename: Thomas
authors.initials: T
authors.lastname: Bieber
authors.forename: Monika-H
authors.initials: MH
authors.lastname: Schmid-Wendtner
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000473:pathology*; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012306:Risk; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D013997:Time Factors; D047368:Tumor Burden