Prognostic Significance of Molecular Staging Study of Sentinel Lymph Nodes by Reverse Transcriptase-Polymerase Chain Reaction for Tyrosinase in Melanoma Patients

Department of Dermatology, Hospital Universitario Germans Trias i Pujol, Carretera Canyet s/n., 08916, Badalona, Spain.
Annals of Surgical Oncology (Impact Factor: 3.93). 08/2006; 13(7):910-8. DOI: 10.1245/ASO.2006.12.010
Source: PubMed


We performed this study to evaluate the clinical effect of microscopic and submicroscopic metastases in sentinel lymph nodes (SLNs) from patients with early-stage melanoma.
Patients with confirmed cutaneous melanoma (American Joint Committee on Cancer stages I and II) underwent standard lymphoscintigraphy and SLN biopsy. Serial sections were divided between routine histopathology with hematoxylin and eosin plus immunohistochemistry for HMB-45 and molecular analysis by nested reverse transcriptase-polymerase chain reaction (RT-PCR) assay for tyrosinase (using beta-actin as a control).
Of 180 patients analyzed (318 SLNs), 38 (21%) patients had positive SLN(s) by routine hematoxylin and eosin and immunohistochemistry (microscopic disease; group 1), and 142 (79%) had negative histological results. Analysis by RT-PCR detected tyrosinase in at least 1 SLN from 124 (69%) patients. Among patients with histologically negative SLN(s), tyrosinase was detected in 86 (48%) patients (submicroscopic disease; group 2), whereas 40 (22%) patients had negative results by both histology and RT-PCR (group 3). Sixteen (9%) patients had histologically negative SLNs and ambiguous RT-PCR results (group 4). Among 138 patients in the analysis of recurrence (mean follow-up, 45 months), only 18 patients had a recurrence: 11 (31%) of 35 in group 1, 5 (10%) of 51 in group 2, and 2 (5%) of 37 in group 3. No recurrences were seen in group 4. Only group 1 had a significantly shorter disease-free survival and overall survival compared with the other groups.
After a long follow-up period, molecular upstaging by tyrosinase RT-PCR failed to detect a subgroup of patients with an increased probability of recurrence.

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