RT-PCR tyrosinase expression in the peripheral blood of melanoma patients.

Controversial data are reported in the literature concerning the role of peripheral blood tyrosinase messenger RNA reverse transcription PCR analysis in melanoma patient management. Some papers assess the clinical relationship between tyrosinase expression and disease outcome, while others address the high degree of variability in the positive rate percentage and demonstrate the transient shedding of melanoma cells in the bloodstream. An overview of the current knowledge about the applications and limitations of tyrosinase analysis compared with other biologic markers is presented herein. Tyrosinase expression should not be considered as a tumor burden-related marker in the peripheral blood, but rather as a measure of the potential increased risk of metastatic spreading. In this view, reverse transcription PCR gains a clinical significance when sequential determinations are performed during follow-up, whereas the evaluation of a single sample, either positive or negative, does not bring any additional clinical information.