Pre-operative Immuno-Nutrition in Radical Cystectomy

Inclusion Criteria:

* Surgical indication to radical cystectomy with diagnosis of muscle invasive bladder cancer (any N, any M), BCG (Bacillus Calmette-Guerin)-unresponsive non-muscle invasive bladder cancer or extensive non-muscle invasive bladder cancer that cannot be treated with endoscopic surgery alone;
* Willingness to participate by signing written informed consent.

Exclusion Criteria:

* Age \< 18 years;
* Pregnant or lactating women;
* Participation in another study with nutritional supplements within the 30 days preceding and during the present study
* Known hypersensitivity or allergy to components of immunonutrition or standard high-calorie high-protein oral nutritional supplement;
* Need for artificial nutrition support due to totally compromised spontaneous food intake;
* Diarrhoea with suspected malabsorption syndrome;
* Inability to consume oral supplements as a consequence of pre-existing disease (e.g. dysphagia) or other factors (e.g. language barrier, psychological disorders, absence of a home caregiver in dependent or elderly patients);
* Kidney failure with need for renal replacement therapy;
* Type 1 diabetes mellitus;
* Type 2 diabetes mellitus requiring insulin therapy and/or inadequate glycaemic control (glycosylated haemoglobin ≥7% and/or fasting plasma glucose ≥150 mg/dL);
* Inability to give an informed consent.