Prospective Multicentre Study of the Use of Ketamine in the Treatment of Refractory Chronic Pain in the French CLCC

Inclusion Criteria: * Patient at least 18 years old at the day of consenting to the study * Patient followed for a solid tumour or a hematological malignancy (treated or under treatment) * Patient presenting cancer chronic pain or post cancer treatment pain * Patient followed by a CLCC's intractable chronic pain consultation or centre * Patient with an indication of 1st Ketamine course: * Analgesic treatment of cancer chronic pain * Analgesic treatment for a post-cancer treatment chronic pain * Help for withdrawal from opioid treatment prescribed for a chronic cancer pain * Patient not previously treated by Ketamine * Patient covered by a medical insurance * Patient and/or family did not decline data collection after complete information (information sheet) Exclusion Criteria: * Patient presenting chronic pains not related to cancer or its treatments * Patient with a proven psychotic history * Patient who is not fluent enough in French