Prognostic value of tyrosinase reverse transcriptase PCR analysis in melanoma sentinel lymph nodes: long‐term follow‐up analysis

Summary Objective.  To determine the prognostic value of detecting tyrosinase transcripts in melanoma sentinel lymph nodes (SLNs). Methods.  Reverse transcription (RT) PCR for tyrosinase mRNA was performed on negative SLNs of 76 patients with melanoma. Results.  Tyrosinase mRNA was found in 39 patients (51.3%). After a median follow-up period of 51 months, significant differences were found in overall survival (OS) but not in disease-free survival (DFS). The 5-year OS and DFS rates were 97.2% and 80%, respectively, for RT-PCR tyrosinase-negative (TN) patients vs. 78.67% and 66.24% for RT-PCR tyrosinase-positive (TP) patients (P = 0.019 and P = 0.38, respectively). Of four progressing patients in the TN group, three relapsed with subcutaneous, soft-tissue or lymph-node metastases, while seven out of nine progressing patients in the TP group relapsed at visceral sites. Conclusions.  No significant differences in DFS were found by RT-PCR tyrosinase expression analysis at melanoma SLNs. Significant differences in OS could be related to a different pattern of relapse and must be confirmed after a longer follow-up time.