Testing the Addition of MEDI4736 (Durvalumab) to Chemotherapy Before Surgery for Patients With High-Grade Upper Urinary Tract Cancer

Inclusion Criteria: * STEP 1 REGISTRATION AND RANDOMIZATION * Patients must be \>= 18 years of age * Patient must have the ability to understand and the willingness to sign a written informed consent document. Patients with impaired decision-making capacity (IDMC) who have a legally authorized representative (LAR) or caregiver and/or family member available will also be considered eligible * Patient must have a diagnosis of high grade upper tract urothelial carcinoma expected within 14 weeks (98 days) prior to registration/randomization with one of the following: * Biopsy (gold standard, preferred) and either upper urinary tract mass on cross-sectional imaging or tumor directly visualized during upper urinary tract endoscopy * High grade cytology and clinically estimated invasive upper urinary tract mass on cross-sectional imaging (e.g., including presence of tumor-related hydronephrosis) or tumor directly visualized during upper urinary tract endoscopy * NOTE: Universal histologic testing of UTUC with additional studies, such as immunohistochemistry and/or microsatellite instability, is strongly recommended to identify patients with high probability of Lynch-related or other germline mutation related cancers whom clinicians should refer for genetic counseling and germline testing (this is not required for eligibility) * Due to the anatomy of upper urinary tract and lack of muscularis propria, pathologic evidence of cT2 on biopsy is usually not possible * Pa…