Study of Circulating Tumoral DNA in Metastatic Choroidal Melanoma

• Assessment and development of circulating tumor DNA detection techniques [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  Quantification of circulating tumor DNA in blood samples. Results expressed in number of samples where circulating DNA is present.
  
  

• Detection technique comparison (PAP (pyrophosphorolysis activated polymerisation), BEAMing, NGS(next sequencing generation)) in terms of feasibility, robustness, sensitivity and cost. [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  The methods of detection which will be used such as the BEAMing, the PAP (Pyrophosphorolysis-activated polymerization) and NGS (next sequencing generation)is techniques of a big specificity capable of detecting a mutant copy among 1.104 wild copies for the BEAMing, 2.109 for the PAP and 1.105 for the NGS. The sensibility of these techniques is limited by the quantity of genomic DNA which we can extract from the sample of blood.
  
  

Biological: Blood sampling
30ml of patient peripherical blood will be collected

Technique development: In first step, the different available techniques will be evaluated for specificity and sensibility using serial dilutions of cell lines with or without GNAQ mutation.

Validation: The tumor DNA detection rate will be estimated from metastatic uveal patient's blood. The investigators will study 40 patients to obtain at least 15 patients bearing a GNAQ mutation in the primitive tumor or in metastasis. With those 15 patients, the investigators will determinate the most sensitive technique and the best cost/efficiency ratio.