Fecal Microbiota Transplantation in Diarrhea Induced by Tyrosine-kinase Inhibitors

Inclusion Criteria: * 18 years old or older * treatment with pazopanib or sunitinib for metastatic RCC diagnosed at histology and measurable according to RECIST criteria version 1.1 * development of diarrhea of 2-3 grade according to Common Terminology Criteria (CTC) for Adverse Events (AE) version 4.0 induced by these drugs. * execution of a CT scan no earlier than 4 weeks before enrollment * good or intermediate prognostic assessment (according to criteria of the prognostic system of the International Metastatic RCC Database Consortium) * performance status equal or lower than 2 * blood count, hepatic and kidney testing within normal limit * ability to give their consent to be included in the study. Exclusion criteria: * another known cause of diarrhea (e.g. infectious gastroenteritis. Clostridium difficile infection, celiac disease, inflammatory bowel disease, irritable bowel syndrome, chronic pancreatitis, biliary salt diarrhea) * previous colorectal surgery or cutaneous stoma * food allergies * recent (\<6 weeks) therapy with drugs that could possibly alter gut microbiota (e.g. antibiotics, probiotics, proton pump inhibitors, immunosuppressants, metformin) * another cancer (except for surgically treated basocellular carcinoma) * brain metastases * decompensated heart failure or heart disease with ejection fraction lower than 30% * severe respiratory insufficiency * psychiatric disorders * pregnancy * unable to give informed consent.