This is a biological study in patients with advanced Ewing Sarcoma who received, according, clinical practice, temozolomide and irinotecan.~The MGMT methylation status will be correlated with the disease clinical data and with the disease response also in term of metabolic activity (if data will be available) The MGMT methylation analysis will be performed extracting from fresh tumor sample, the DNA on the basis of the standard protocols.
This is a biological study in patients with advanced Ewing Sarcoma who received, according, clinical practice, temozolomide and irinotecan The O6-methylguanine-DNA methyltransferase (MGMT) methylation status, will be correlated with the disease clinical data and with the disease response