title: Quantitative measurement of melanoma spread in sentinel lymph nodes and survival.
abstract: BACKGROUND
  Sentinel lymph node spread is a crucial factor in melanoma outcome. We aimed to define the impact of minimal cancer spread and of increasing numbers of disseminated cancer cells on melanoma-specific survival.
  
  
  RESULTS
  We analyzed 1,834 sentinel nodes from 1,027 patients with ultrasound node-negative melanoma who underwent sentinel node biopsy between February 8, 2000, and June 19, 2008, by histopathology including immunohistochemistry and quantitative immunocytology. For immunocytology we recorded the number of disseminated cancer cells (DCCs) per million lymph node cells (DCC density [DCCD]) after disaggregation and immunostaining for the melanocytic marker gp100. None of the control lymph nodes from non-melanoma patients (n = 52) harbored gp100-positive cells. We analyzed gp100-positive cells from melanoma patients by comparative genomic hybridization and found, in 45 of 46 patients tested, gp100-positive cells displaying genomic alterations. At a median follow-up of 49 mo (range 3-123 mo), 138 patients (13.4%) had died from melanoma. Increased DCCD was associated with increased risk for death due to melanoma (univariable analysis; p<0.001; hazard ratio 1.81, 95% CI 1.61-2.01, for a 10-fold increase in DCCD + 1). Even patients with a positive DCCD ≤3 had an increased risk of dying from melanoma compared to patients with DCCD = 0 (p = 0.04; hazard ratio 1.63, 95% CI 1.02-2.58). Upon multivariable testing DCCD was a stronger predictor of death than histopathology. The final model included thickness, DCCD, and ulceration (all p<0.001) as the most relevant prognostic factors, was internally validated by bootstrapping, and provided superior survival prediction compared to the current American Joint Committee on Cancer staging categories.
  
  
  CONCLUSIONS
  Cancer cell dissemination to the sentinel node is a quantitative risk factor for melanoma death. A model based on the combined quantitative effects of DCCD, tumor thickness, and ulceration predicted outcome best, particularly at longer follow-up. If these results are validated in an independent study, establishing quantitative immunocytology in histopathological laboratories may be useful clinically.
authors.affiliation: Department of Dermatology, University of Tübingen, Tübingen, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Ulmer
authors.affiliation: Department of Medical Biometry, University of Tübingen, Tübingen, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Dietz
authors.affiliation: Chair of Experimental Medicine and Therapy Research, Department of Pathology, University of Regensburg, Regensburg, Germany.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Hodak
authors.affiliation: Chair of Experimental Medicine and Therapy Research, Department of Pathology, University of Regensburg, Regensburg, Germany ; Project Group Personalized Tumor Therapy, Fraunhofer-Institut für Toxikologie und Experimentelle Medizin, Regensburg, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Polzer
authors.affiliation: Chair of Experimental Medicine and Therapy Research, Department of Pathology, University of Regensburg, Regensburg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Scheitler
authors.affiliation: Chair of Experimental Medicine and Therapy Research, Department of Pathology, University of Regensburg, Regensburg, Germany.
authors.forename: Murat
authors.initials: M
authors.lastname: Yildiz
authors.affiliation: Chair of Experimental Medicine and Therapy Research, Department of Pathology, University of Regensburg, Regensburg, Germany ; Project Group Personalized Tumor Therapy, Fraunhofer-Institut für Toxikologie und Experimentelle Medizin, Regensburg, Germany.
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Czyz
authors.affiliation: Department of Dermatology, University of Tübingen, Tübingen, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Lehnert
authors.affiliation: Department of Gynecology, University of Düsseldorf, Düsseldorf, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Fehm
authors.affiliation: Department of Dermatology, University of Regensburg, Regensburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Hafner
authors.affiliation: Department of Dermatology, University of Tübingen, Tübingen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schanz
authors.affiliation: Department of Dermatology, University of Tübingen, Tübingen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Röcken
authors.affiliation: Department of Dermatology, University of Tübingen, Tübingen, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Garbe
authors.affiliation: Department of Dermatology, University of Tübingen, Tübingen, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Breuninger
authors.affiliation: Department of Dermatology, University of Tübingen, Tübingen, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Fierlbeck
authors.affiliation: Chair of Experimental Medicine and Therapy Research, Department of Pathology, University of Regensburg, Regensburg, Germany ; Project Group Personalized Tumor Therapy, Fraunhofer-Institut für Toxikologie und Experimentelle Medizin, Regensburg, Germany.
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Klein
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D016009:Chi-Square Distribution; D002648:Child; D055028:Comparative Genomic Hybridization; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008545:Melanoma / Q000737:chemistry / Q000235:genetics / Q000401:mortality* / Q000556:secondary*; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000737:chemistry / Q000235:genetics / Q000401:mortality* / Q000473:pathology*; D013997:Time Factors; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor