A Phase I/II Study to Determine the Safety and Efficacy of a Combination of Green Tea and Quercetin With Docetaxel in Castration-resistant Prostate Cancer Patients

Inclusion Criteria: * Signed and dated informed consent form and HIPPA (Health Insurance Portability and Accountability Act) authorization. * Stated willingness to comply with all study procedures and availability for the duration of the study. * Male patients 18 years or older * Diagnosed with metastatic prostate cancer * History of confirmed progressive disease with concurrent use of medical castration (e.g. luteinizing hormone-releasing hormone analogue), or surgical castration * Confirmed progressive disease with concurrent use of enzalutamide, apalutamide, darolutamide, and/or abiraterone acetate * Clinical decision to start doc infusion with prednisone treatment * Adequate bone marrow function (absolute neutrophil count (ANC) more than1500 cells/mm³, platelet count more than 100,000 cells/mm³) * Adequate liver function (total bilirubin less than upper limit of normal (ULN), alanine aminotransferase (ALT) less than 1.5 x ULN, aspartate aminotransferase (AST) less than 1.5 x ULN) * Adequate renal function (serum creatinine level within normal limits) * At least a 6-month or greater life expectancy * Willing to stop consuming tea or tea-containing products and quercetin supplements throughout the entire intervention period except for the green tea extract and quercetin provided during study intervention Exclusion Criteria: * Prior treatment of chemotherapy and/or radiotherapy for metastatic disease * Any comorbid condition that would preclude the administration of docetaxel/prednisone * Ongoing alcohol abuse * Significant medical or psychiatric conditions that would make the patient a poor protocol candidate * Prior allergic reaction to tea, tea products or quercetin supplements * Allergies to multiple food items or nutritional supplements