Relevance of micrometastases detected by reverse transcriptase-polymerase chain reaction for melanoma recurrence: systematic review and meta-analysis

Abstract

CONTEXT: Cutaneous melanoma presents significant morbidity and mortality. Nowadays, about 90% of them are diagnosed by clinical examination and most are localized melanomas. Sentinel node biopsy has brought about a new and interesting approach towards localized cutaneous melanoma. The meaning of micrometastases in sentinel nodes diagnosed by the reverse transcriptase-polymerase chain reaction is not well established. OBJECTIVE: To define the real value of micrometastases diagnosed by the reverse transcriptase-polymerase chain reaction in relation to melanoma recurrence. METHODS: Systematic literature review and meta-analysis. The Cochrane Library, Medline, Embase and Lilacs were the databases searched. We used the following key words: sentinel node and melanoma; sentinel node and reverse transcriptase-polymerase chain reaction; melanoma and reverse transcriptase-polymerase chain reaction. Cohort studies enrolling localized cutaneous melanoma patients who underwent sentinel node biopsy were selected. Sentinel node evaluations included hematoxylin and eosin, immunohistochemistry and reverse transcriptase-polymerase chain reaction. RESULTS: Out of the 1,542 studies evaluated, four were eligible. The four studies, when combined, were statistically homogeneous. The sample totaled 450 patients grouped as follows: 163 with a sentinel node negative to hematoxylin eosin and immunohistochemistry and positive to the reverse transcriptase-polymerase chain reaction; 192 with a sentinel node negative to hematoxylin eosin, immunohistochemistry and the reverse transcriptase-polymerase chain reaction and 95 patients with a sentinel node positive to hematoxylin eosin and/or immunohistochemistry. We analyzed the first two groups. The meta-analysis for the random model showed an increased effect from a positive reverse transcriptase-polymerase chain reaction on the recurrence rate. A similar result occurred in the meta-analysis for the fixed effect model. CONCLUSION: Patients with a positive reverse transcriptase-polymerase chain reaction had a greater recurrence rate than those with a negative reverse transcriptase-polymerase chain reaction. This suggests an important role for the reverse transcriptase-polymerase chain reaction in sentinel node examinations. In view of the small sample, a clinical trial could better evaluate this question.

Recorrência em pacientes portadores de melanoma cutâneo submetidos a biópsia de linfonodo sentinela: seguimento mediano de 37 meses

“…A relevância das micrometástases detectadas por RT-PCR na recorrência do melanoma não está ainda bem estabelecida. Uma revisão sistemática da literatura médica com metanálise mostrou que o diagnóstico de micrometástase por RT-PCR exclusivo tem valor de pior prognóstico para estes pacientes 19 . O inconveniente desta técnica é que ainda apresenta altos índices de fal- so-positivos o que pode ser diminuído pela utilização de múltiplos marcadores 20,21 .…”

Pesquisa do linfonodo sentinela em pacientes com melanoma: experiência com fitato marcado com Tecnécio-99m e revisão da literatura

“…6,12,13 In a recent review of 1,135 24 The clinical significance of a micrometastasis (mainly when detected only by PCR) and its impact on survival rates, however, remain controversial. 32,33 The infiltration of SNL 36,37,38,39 Regional recurrence among SNL Uma biópsia negativa do LNS, entretanto, não é garantia de que o paciente não irá apresentar recorrências no futuro. Vários autores relatam recorrência entre um e 6% dos pacientes com LNS negativo.…”

Equipamento brasileiro de detecção gama intra-operatória para biópsia de linfonodo sentinela

“…O procedimento de BLS envolve a linfocintilografia pré-operatória, o mapeamento linfático intra-operatório com corante vital, a DGI e o exame histopatológico do LS [6][7][8] .…”