Overall survival and time to progress will be presented as Kaplan-Meier curves together with median survival time and time to progression, respectively. The estimates for cumulative 1- and 5-year overall survival will be compared between pts given sevoflurane or propofol. In a next step, Cox Proportional hazard models will be calculated to assess the risk of death adjusted for potential effect modifiers and confounders. There will also be stratifications for different types of tumors, cardio-pulmonary status, ASA-class etc. Hazard ratios with 95 % confidence intervals will be presented for all models.