Combined Treatment With Capecitabine and Immunotherapy Versus Immunotherapy Alone in Advanced Renal Cell Carcinoma

Inclusion Criteria: * Histologically confirmed renal cell carcinoma (primary tumour or biopsy/surgery of metastases) * Radiologically confirmed metastatic disease * Surgically removed primary tumour so feasible (nephrectomy or nephron-sparing surgery as indicated) * Karnofsky-Performance Status \>70% * Age 19-75 years * Life expectancy of at least 3 months * Adequate bone marrow function (i.e. white blood cell count above 3000/μL, platelet count above 75 000 /μL, hemoglobin above 9 mg/dl) * Adequate organ function (i.e. serum creatinine, bilirubin and AST below 1.25 x the upper limit of the institutions' normal range) * Negative pregnancy test for female patients * Written informed consent Exclusion Criteria: * Age \<19 or \>75 years * Karnofsky-Performance Status \< 70% * Untreated or uncontrolled brain metastases * Second neoplasia * Primary tumour surgically removable * Solitary, surgically removable metastases * Major concomitant diseases of the cardiovascular, respiratory or renal systems, as well as active systemic infections * Severe renal disease or liver insufficiency or myeloid dysfunction (including patients with a history of a disease that is likely to interfere with the metabolism or excretion of the test medication) * Other less common diseases as peptic ulcer disease, inflammatory bowel disease, autoimmune disease (severe known psoriasis, idiopathic thrombocytopenic purpura, lupus erythematosus, autoimmune hemolytic anemia, scleroderma, rheumatoid arthritis etc.) * Drug addiction (including excessive alcohol consumption) within 1 year prior to study start. * History of other conditions consistent with decompensated liver disease or other evidence of bleeding form esophageal varices. * History of chronic hepatitis and immunsupressiva * Known HIV Infection * Evidence of allergy or hypersensitivity against recombinant Interferon alfa-2a or other components of preparation. * History of severe psychiatric disease, especially depression. Severe psychiatric disease is defined as treatment with an antidepressant medication or a major tranquilizer at therapeutic doses for major depression or psychosis, respectively, for at least 3 months at any previous time or any history of the following: a suicidal attempt, hospitalization for psychiatric disease, or a period of disability due to a psychiatric disease. * Seizure disorders and /or compromised central nervous system function. * History of evidence of severe retinopathy * Patient unwilling or unable to give informed consent * Pregnancy or breastfeeding