title: Incidence of sentinel node metastasis in patients with thin primary melanoma (< or = 1 mm) with vertical growth phase.
abstract: BACKGROUND
  Patients with thin primary melanomas (< or = 1 mm) generally have an excellent prognosis. However, the presence of a vertical growth phase (VGP) adversely impacts the survival rate. We report on the rate of occurrence of nodal metastasis in patients with thin primary melanomas with a VGP who are offered sentinel lymph node (SLN) biopsy.
  
  
  METHODS
  Among 235 patients with clinically localized cutaneous melanomas who underwent successful SLN biopsy, 71 had lesions 1 mm or smaller with a VGP. The SLN was localized by using blue dye and a radiotracer. If negative for tumor by using hematoxylin and eosin staining, the SLN was further examined by immunohistochemistry.
  
  
  RESULTS
  The rate of occurrence of SLN metastasis was 15.2% in patients with melanomas deeper than 1 mm and 5.6% in patients with thin melanomas. Three patients with thin melanomas and a positive SLN had low-risk lesions, based on a highly accurate six-variable multivariate logistic regression model for predicting 8-year survival in stage I/II melanomas. The fourth patient had a low- to intermediate-risk lesion based on this model. At the time of the lymphadenectomy, one patient had two additional nodes with metastasis.
  
  
  CONCLUSIONS
  VGP in a melanoma 1 mm or smaller seems to be a risk factor for nodal metastasis. The risk of nodal disease may not be accurately predicted by the use of a multivariate logistic regression model that incorporates thickness, mitotic rate, regression, tumor-infiltrating lymphocytes, sex, and anatomical site. Patients with thin lesions having VGP should be evaluated for SLN biopsy and trials of adjuvant therapy when stage III disease is found.
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia 19104, USA.
authors.forename: I
authors.initials: I
authors.lastname: Bedrosian
authors.forename: M B
authors.initials: MB
authors.lastname: Faries
authors.forename: D
authors.initials: D
authors.lastname: Guerry
authors.forename: R
authors.initials: R
authors.lastname: Elenitsas
authors.forename: L
authors.initials: L
authors.lastname: Schuchter
authors.forename: R
authors.initials: R
authors.lastname: Mick
authors.forename: F R
authors.initials: FR
authors.lastname: Spitz
authors.forename: L P
authors.initials: LP
authors.lastname: Bucky
authors.forename: A
authors.initials: A
authors.lastname: Alavi
authors.forename: D E
authors.initials: DE
authors.lastname: Elder
authors.forename: D L
authors.initials: DL
authors.lastname: Fraker
authors.forename: B J
authors.initials: BJ
authors.lastname: Czerniecki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D005260:Female; D006801:Humans; D016015:Logistic Models; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008297:Male; D008545:Melanoma / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D011877:Radionuclide Imaging; D012878:Skin Neoplasms / Q000473:pathology* / Q000601:surgery