Detection of circulating melanoma cells in choroidal melanocytic lesions.

Manuel F Bande,Manuel F Bande,Manuel F Bande,Purificacion Mera,Maria Santiago,Carmela Capeans,Antonio Piñeiro,Antonio Piñeiro,Antonio Piñeiro,Laura Muinelo-Romay,Maria Pardo,Maria Jose Blanco

doi:10.1186/s13104-015-1420-5

Abstract

PurposeTo detect and quantify circulating tumour cells (CTCs) in peripheral blood of patients with uveal melanoma primary non-metastatic tumours, and to analyze the possible relationship between CTCs and clinical risk factors.MethodsProspective study with two clinical groups: 4 patients diagnosed with choroidal nevus and 8 patients with choroidal melanoma prior to treatment. A single sample of 7.5 mL of peripheral blood was taken and the CTCs were isolated using a CellSearch system that captures positive cells for the CD146 antigen (MUC18).ResultsNone of the patients with choroidal nevus showed CTCs in peripheral blood. More than one CTC/7.5 mL was detected in 50 % of patients with choroidal melanoma prior to treatment. The higher level of CTC cells in peripheral blood (3/7.5 mL) was detected in the patient with the larger choroidal melanoma which also presented extrascleral extension and epithelioid pathology.ConclusionPerforming an analysis with the CellSearch system allows to quantify the choroidal melanoma CTCs in peripheral blood. This finding highlights the potential usefulness of this technique to achieve the correct stratification and monitoring of the treatment.

Highlights

Despite the successful treatment of uveal melanoma (UM) primary tumors, patients remain at risk of developing metastases for more than 20 years after the initial diagnosis
The CD146-expressing cells were stained with the fluorescent nucleic acid dye 4′,6-diamidino-2-phenylindole dihydrocloride (DAPI) and with a combination of fluorescent antibodies against high-molecular-weight melanoma-associated antigen (MEL), CD34 and CD45 to distinguish melanoma cells from leukocytes and endothelial cells (Fig. 1)
Among the eight patients with non-treated choroidal melanoma, 50 % displayed more than one circulating tumour cells (CTCs) per

Summary

Introduction

Despite the successful treatment of uveal melanoma (UM) primary tumors, patients remain at risk of developing metastases for more than 20 years after the initial diagnosis. In the Collaborative Ocular Melanoma Study (COMS), Kaplan–Meier analyses estimated that the 2-, 5-, and 10-year metastasis rates were 10, 25, and 34 %, respectively. Only 0.24 % of patients exhibited detectable metastases at the time of diagnosis [1]. The CellSearch system (Veridex) was developed to identify and quantify CTCs in the peripheral blood by immunomagnetic isolation and inmunohistochemical detection. This platform obtained the Food and Drug Administration (FDA) clearance for the CTC enumeration in patients with breast, colon, or prostate cancers [2, 3].

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Conclusion