title: Prediction of melanoma metastasis by the Shields index based on lymphatic vessel density.
abstract: BACKGROUND
  Melanoma usually presents as an initial skin lesion without evidence of metastasis. A significant proportion of patients develop subsequent local, regional or distant metastasis, sometimes many years after the initial lesion was removed. The current most effective staging method to identify early regional metastasis is sentinel lymph node biopsy (SLNB), which is invasive, not without morbidity and, while improving staging, may not improve overall survival. Lymphatic density, Breslow's thickness and the presence or absence of lymphatic invasion combined has been proposed to be a prognostic index of metastasis, by Shields et al in a patient group.
  
  
  METHODS
  Here we undertook a retrospective analysis of 102 malignant melanomas from patients with more than five years follow-up to evaluate the Shields' index and compare with existing indicators.
  
  
  RESULTS
  The Shields' index accurately predicted outcome in 90% of patients with metastases and 84% without metastases. For these, the Shields index was more predictive than thickness or lymphatic density. Alternate lymphatic measurement (hot spot analysis) was also effective when combined into the Shields index in a cohort of 24 patients.
  
  
  CONCLUSIONS
  These results show the Shields index, a non-invasive analysis based on immunohistochemistry of lymphatics surrounding primary lesions that can accurately predict outcome, is a simple, useful prognostic tool in malignant melanoma.
authors.affiliation: Microvascular Research Laboratories, Bristol Heart Institute, Department of Physiology and Pharmacology, University of Bristol, Bristol, UK. Dave.Bates@bris.ac.uk.
authors.forename: Maxine S
authors.initials: MS
authors.lastname: Emmett
authors.forename: Kirsty E
authors.initials: KE
authors.lastname: Symonds
authors.forename: Howard
authors.initials: H
authors.lastname: Rigby
authors.forename: Martin G
authors.initials: MG
authors.lastname: Cook
authors.forename: Rebecca
authors.initials: R
authors.lastname: Price
authors.forename: Chris
authors.initials: C
authors.lastname: Metcalfe
authors.forename: Antonio
authors.initials: A
authors.lastname: Orlando
authors.forename: David O
authors.initials: DO
authors.lastname: Bates
mesh_terms: D000328:Adult; D000368:Aged; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D042601:Lymphatic Vessels / Q000473:pathology*; D008545:Melanoma / Q000556:secondary* / Q000601:surgery; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D012042:Registries; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000473:pathology* / Q000601:surgery; D013997:Time Factors