Clinical significance of the RT-PCR positive sentinel node in melanoma

BACKGROUND: The clinical relevance of RT-PCR positivity for melanoma markers in the sentinel node remains controversial. Our purpose was to determine whether patients with a histologically negative but RT-PCR positive node were at an increased risk for recurrence than their RT-PCR negative counterparts. METHODS: Thirty-nine adult patients underwent sentinel node biopsies for melanoma between 1998 and 2000. Each sentinel node was bivalved. Half was serially sectioned and examined by routine hematoxylin and eosin (H&E) and immunohistochemistry (IHC; S100, HMB-45, melanA, and tyrosinase). The other half was analyzed by a nested RT-PCR assay for tyrosinase. RESULTS: Patients were followed for recurrence with a mean follow-up of 71.1 months. The odds ratio of recurrence for RT-PCR positive versus RT-PCR negative patients was 1.39 (0.34, 5.62; p = 0.73). Within the histology negative subgroups, the risk of recurrence in the RT-PCR positive group (26.7%) was not significantly different from the risk of recurrence in the RT-PCR negative group (22.2%) (p = 0.33 chi-squared). RT-PCR of the sentinel node was not a predictor for recurrence on multivariate analysis (p = 0.65). CONCLUSION: Sentinel node RT-PCR positivity did not risk stratify histologically negative melanoma patients beyond routine pathologic examination in this series.