title: Ultrathin primary is a marker for worse prognosis in lymph node-positive cutaneous melanoma.
abstract: BACKGROUND
  Lymph lymph node metastasis from melanoma ≤0.50 mm (ultrathin) is an infrequent event. However, because many newly diagnosed melanomas are ultrathin, a significant proportion of patients who present with lymph node disease have an ultrathin melanoma. The authors hypothesized that ultrathin melanomas that present with lymph node metastasis represent biologically aggressive lesions with a worse prognosis.
  
  
  METHODS
  The Surveillance, Epidemiology, and End Results registry data were queried to identify patients with cutaneous melanoma who presented with lymph node metastasis diagnosed between 1998 and 2008. Hazard ratios (HRs) from Cox proportional hazards regression models were used to compare disease-specific survival (DSS) between various tumor depths.
  
  
  RESULTS
  In total, 6134 patients with lymph node-positive melanoma were identified and stratified according to tumor depth, including 588 (10%) with a tumor depth ≤0.50 mm, 519 (8%) with a tumor depth from 0.51 to 1.00 mm, 1669 (27%) with a tumor depth from 1.01 to 2.00 mm, 1871 (31%) with a tumor depth from 2.01 to 4.00 mm, and 1487 (24%) with a tumor depth >4.00 mm; and the respective 5-year DSS rates were 63%, 76%, 75%, 60%, and 43%. Multivariable analysis confirmed a similar trend in HRs for DSS: The HR was 1.00 for a tumor depth ≤0.50 mm (reference category) and 0.64 (P < .001), 0.65 (P < .001), 0.95 (P = .57), and 1.42 (P < .001) for tumor depths of 0.51 to 1.00 mm, 1.01 to 2.00 mm, 2.01 to 4.00 mm, and >4.00 mm, respectively. This association of tumor depth with DSS persisted for N1 and N2 disease but not for N3 disease.
  
  
  CONCLUSIONS
  Ultrathin melanoma (≤0.50 mm) was identified as a marker of poor prognosis in the setting of lymph node metastasis. These results may improve recommendations for adjuvant therapy, surveillance protocols, and risk stratification for clinical trials.
authors: Department of Surgery, Mayo Clinic Florida, 4500 San Pablo Road, Jacksonville, FL 32224, USA. bagaria.sanjay@mayo.edu
authors: Sanjay P
authors: SP
authors: Bagaria
authors: Partha S
authors: PS
authors: Ray
authors: Richard W
authors: RW
authors: Joseph
authors: Michael G
authors: MG
authors: Heckman
authors: Bhupendra
authors: B
authors: Rawal
authors: Richard J
authors: RJ
authors: Gray
authors: Barbara
authors: B
authors: Pockaj
authors: Nabil
authors: N
authors: Wasif
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008545:Melanoma / Q000401:mortality* / Q000473:pathology* / Q000556:secondary / Q000601:surgery; D008875:Middle Aged; D015999:Multivariate Analysis; D010173:Palpation; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D018426:SEER Program; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D014481:United States / Q000453:epidemiology