Quantification of melanoma micrometastases in sentinel lymph nodes using real-time RT-PCR

J Invest Dermatol. 2005 Mar;124(3):633-7. doi: 10.1111/j.0022-202X.2005.23633.x.


Detection of micrometastases in the regional tumor-draining lymph nodes is critical for staging and prognosis in melanoma patients. We applied a quantitative multiple-marker RT-PCR assay to improve the detection of occult melanoma cells in the sentinel lymph node (SLN). From 139 patients with primary cutaneous melanoma who underwent sentinel lymphadenectomy, a total of 235 SLN were assessed for Melan-A and tyrosinase expression by real-time quantitative RT-PCR. Twenty-three patients (17%) were positive by histopathology and expressed messenger RNA of one or two markers. Of the patients with histopathologically negative SLN 39 (28%) were reclassified by positive RT-PCR. Patients were examined for tumor recurrences during a median follow-up period of 29 mo. Tumor recurrences were demonstrated in eight patients (35%) with histopathologically positive SLN, in four patients (10%) with submicroscopic tumor cells detected exclusively by real-time RT-PCR, and in none of the patients negative by both methods. The differences in recurrence rates were statistically significant (p=0.01). These data indicate that real-time quantitative RT-PCR for the detection of minimal residual melanoma in SLN improves the prediction of disease-free survival.

Publication types

  • Clinical Trial

MeSH terms

  • Antigens, Neoplasm / genetics
  • Disease-Free Survival
  • Follow-Up Studies
  • Genetic Testing / methods
  • Humans
  • Lymph Node Excision
  • Lymphatic Metastasis*
  • MART-1 Antigen
  • Melanoma / epidemiology
  • Melanoma / genetics
  • Melanoma / secondary*
  • Monophenol Monooxygenase / genetics
  • Neoplasm Proteins / genetics
  • Neoplasm Recurrence, Local / epidemiology
  • Neoplasm Recurrence, Local / genetics
  • Neoplasm Recurrence, Local / pathology
  • Neoplasm, Residual / epidemiology
  • Neoplasm, Residual / genetics
  • Neoplasm, Residual / pathology
  • Predictive Value of Tests
  • Reverse Transcriptase Polymerase Chain Reaction / methods*
  • Risk Factors
  • Sentinel Lymph Node Biopsy
  • Skin Neoplasms / epidemiology
  • Skin Neoplasms / genetics
  • Skin Neoplasms / pathology*


  • Antigens, Neoplasm
  • MART-1 Antigen
  • MLANA protein, human
  • Neoplasm Proteins
  • Monophenol Monooxygenase