Inclusion Criteria:

• Males and females, age 18 years or older.
• Clinical diagnosis of localized (clinical AJCC stage Ta-T4N0M0) low- and high-grade UC of the renal pelvis and/or ureter.
• Plan to undergo RNU.
• Adequate bone marrow, renal and hepatic function:
  • Creatinine < 2.2 mg/dL (194 mmol/L);
  • Adequate hematologic function (hemoglobin > 9 g/dL; white blood cell count ≥ 3000/μL; platelet count >75,000/μL and <500,000/μL);
  • Serum bilirubin, alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase levels below 2 times the institution’s upper limits of normal.
• Easter Cooperative Oncology Group (ECOG) performance status score 0 - 2.
• Suitable candidate for surgery at the discretion of the investigator.
• Patient must be capable of giving appropriate approved informed consent or have an appropriate representative available to do.
• Patient with a prior malignancy allowed if adequately treated > 3 years ago with no current evidence of disease.
• Patient with any current malignancy except for basal or squamous cell skin cancers, noninvasive cancer of the cervix, or any other cancer deemed to be of low-risk for progression or patient morbidity during the trial period (i.e. Gleason 6 prostate cancer, renal mass < 3 cm).
• Women of childbearing potential (WOCBP) must have a negative pregnancy urine test within 28 days of registration, and be using an adequate method of contraception to avoid pregnancy prior to and for at least 6 months after gemcitabine instillation to minimize the risk of pregnancy.
• Male patient who has a partner that is a WOCBP must agree to use physician-approved contraceptive methods (e.g., abstinence, condoms, vasectomy) and should avoid conceiving children prior to and for 6 months following gemcitabine instillation.

Exclusion Criteria:

• Pure non-urothelial histology; urothelial carcinoma with differentiation allowed.
• Evidence of nodal or distant metastases; enlarged retroperitoneal lymph nodes > 2cm or histologically positive lymph nodes.
• History of UC of the bladder within 12 months preceding RNU, or receipt of intravesical therapy within 6 months.
• History of or current prostatic urethral, urethral, or contralateral upper tract UC.
• History of radical cystectomy or partial cystectomy.
• Planned radical cystectomy at time of RNU.
• Symptomatic urinary tract infection of bacterial cystitis (once satisfactorily treated, patients can enter the study).
• Women who are pregnant or breastfeeding.
• Prisoners or subjects who are involuntarily incarcerated.
• Subjects who are involuntarily incarcerated.
• Inability for adequate follow-up, including concerns for patient compliance or geographic proximity.