# Upper Tract Urothelial Carcinoma ## Overview Upper tract urothelial carcinoma (UTUC) management involves a combination of diagnostic ureteroscopy, selective cytology, radical nephroureterectomy with bladder cuff excision, and kidney-sparing approaches. Neoadjuvant chemotherapy plays an important role in high-risk cases, while mitomycin gel instillation offers a novel kidney-sparing treatment option for low-grade tumors. --- ## Epidemiology UTUC accounts for approximately 5-10% of all urothelial carcinomas, making it relatively uncommon. The annual incidence ranges from 1 to 2 cases per 100,000 individuals. It predominantly affects males, with a male-to-female ratio of about 3:1, and typically presents in patients aged 70 to 80 years. The renal pelvis is the most common site of involvement, comprising about 65% of cases, while the ureter accounts for the remaining 35%. Smoking is the most significant risk factor, along with exposure to occupational carcinogens and aristolochic acid, which is implicated in Balkan endemic nephropathy and Chinese herb nephropathy. Genetic predisposition is also important, particularly Lynch syndrome associated with MSH2 mutations, which increases the risk of UTUC by 10 to 20 times. Approximately 17% of patients with UTUC develop subsequent bladder cancer, and conversely, 2-6% of bladder cancer patients develop UTUC. Bilateral disease occurs in 2-5% of cases. --- ## Presentation The most common presenting symptom of UTUC is hematuria, which can be gross or microscopic and occurs in 70-80% of patients. Flank pain due to obstruction is reported in 20-30% of cases. Some patients are diagnosed incidentally during imaging studies such as CT urograms, which may reveal filling defects or hydronephrosis. Constitutional symptoms typically arise only in advanced disease. --- ## Diagnostic Workup ### Imaging The initial imaging modality of choice is the CT urogram, which has a sensitivity of approximately 90-95% for detecting upper tract tumors. It can demonstrate filling defects, wall thickening, or hydronephrosis, with the delayed excretory phase being essential to visualize urothelial details. MRI urogram serves as an alternative for patients with contrast allergies or renal insufficiency. When CT findings are inconclusive, retrograde pyelography can be employed to better define filling defects and strictures. ### Ureteroscopy Ureteroscopy is both diagnostic and potentially therapeutic. Using a flexible ureteroscope, direct visualization of the tumor is possible, allowing for biopsy with cup forceps or basket devices, although the samples tend to be small. This procedure helps assess tumor grade, size, multifocality, and location. However, biopsies underestimate tumor grade in up to 30% of cases and cannot determine the depth of invasion or stage. ### Selective Cytology Selective cytology is obtained during ureteroscopy or retrograde catheterization by washing the renal pelvis or ureter with saline. It has high specificity for detecting high-grade tumors but low sensitivity for low-grade lesions. When positive cytology is combined with a filling defect on imaging, it provides strong evidence for UTUC. ### Cystoscopy Cystoscopy is mandatory to exclude concurrent bladder cancer, which is present in 8-13% of patients at the time of UTUC diagnosis. --- ## Risk Stratification ### Low-Risk UTUC Low-risk UTUC is characterized by a unifocal tumor smaller than 2 cm, low-grade histology on biopsy, absence of invasive features on imaging such as hydronephrosis or wall thickening, and normal or low-grade cytology. ### High-Risk UTUC High-risk disease includes multifocal tumors, lesions larger than 2 cm, high-grade histology on biopsy or cytology, sessile tumor architecture observed during ureteroscopy, presence of hydronephrosis, variant histology, or a history of radical cystectomy for bladder cancer. | Feature | Low-Risk | High-Risk | |---|---|---| | Size | <2 cm | ≥2 cm | | Focality | Unifocal | Multifocal | | Grade | Low-grade | High-grade | | Architecture | Papillary | Sessile | | Imaging | No hydronephrosis or wall thickening | Hydronephrosis or wall thickening | | Cytology | Normal or low-grade | High-grade | | Management | Kidney-sparing (ureteroscopy, instillation) | Radical nephroureterectomy +/- neoadjuvant chemo | --- ## Surgical Management ### Radical Nephroureterectomy (RNU) with Bladder Cuff Radical nephroureterectomy with bladder cuff excision remains the gold standard treatment for high-risk UTUC. This procedure involves removal of the entire kidney, ureter, and a cuff of bladder tissue at the ureteral orifice. Excision of the bladder cuff is critical to prevent tumor recurrence at the distal ureteral stump. Open cuff excision, which entails direct cystotomy and circumferential excision of the ureteral orifice, is preferred due to superior oncologic outcomes. Endoscopic approaches such as ureteral stripping (intussusception) or transurethral resection of the orifice (pluck technique) are alternatives but generally less favored. Surgical approaches include open surgery with two incisions (flank plus lower midline or Gibson incision) or a single midline incision, laparoscopic or robotic nephroureterectomy combined with open bladder cuff excision, and fully robotic techniques which are emerging but require careful planning for specimen extraction. Template lymph node dissection is increasingly recommended for high-risk disease. The dissection template depends on tumor location: for renal pelvis and upper ureter tumors, lymph nodes include hilar, paracaval (right side), and para-aortic (left side); for mid-ureter tumors, the ipsilateral common iliac nodes are targeted; and for distal ureter tumors, pelvic lymph nodes including obturator, internal iliac, and external iliac nodes are removed. ### Kidney-Sparing Surgery Kidney-sparing surgery is indicated for low-risk UTUC, patients with a solitary kidney (imperative indication), bilateral disease, chronic kidney disease, or comorbidities that preclude radical surgery. Options include ureteroscopic ablation using laser energy (holmium or thulium lasers) with follow-up ureteroscopy every 3 to 6 months, segmental ureterectomy with ureteral reimplantation for low-risk distal ureteral tumors, and percutaneous approaches which are rarely used but may be considered for large renal pelvis tumors in imperative settings. Endoscopic management requires that complete tumor ablation is achievable, low-grade histology is confirmed, and the patient is compliant with intensive surveillance involving ureteroscopy every 3 to 6 months for the first two years, then every 6 to 12 months thereafter. Recurrence rates with endoscopic management range from 30 to 50%, but most recurrences can be managed with repeat treatment. --- ## Instillation Therapy ### Mitomycin Gel (UGN-101 / Jelmyto) Mitomycin C formulated in a reverse thermal gel, which is liquid at room temperature and gels at body temperature, was FDA-approved in 2020 for low-grade UTUC. The OLYMPUS trial demonstrated a complete response rate of 59% for low-grade tumors in the renal pelvis. The gel is administered via retrograde ureteral catheter or nephrostomy tube in six weekly instillations. This therapy enables a kidney-sparing approach for low-grade tumors that are difficult to access endoscopically. The most significant side effect is ureteral stricture, occurring in up to 40% of patients, along with flank pain and urinary tract infections. Strictures are managed with stenting or balloon dilation. ### Adjuvant Intravesical Chemotherapy (Post-RNU) A single postoperative intravesical instillation of pirarubicin or mitomycin C reduces bladder recurrence after radical nephroureterectomy. This approach is supported by the ODMIT-C and POUT trial substudy data and is typically administered during the first postoperative catheterization, within 2 to 10 days after surgery. --- ## Neoadjuvant and Adjuvant Systemic Therapy ### Neoadjuvant Chemotherapy Neoadjuvant chemotherapy is rationalized by the fact that glomerular filtration rate (GFR) declines after nephroureterectomy due to loss of ipsilateral kidney function, reducing eligibility for cisplatin-based chemotherapy postoperatively. Administering cisplatin-based chemotherapy while the patient still has two functioning kidneys improves tolerability and efficacy. Although prospective data are limited, emerging evidence supports neoadjuvant chemotherapy for high-risk UTUC, with regimens including dose-dense MVAC (methotrexate, vinblastine, doxorubicin, cisplatin) and gemcitabine-cisplatin. ### Adjuvant Chemotherapy The POUT trial established that adjuvant platinum-based chemotherapy after radical nephroureterectomy improves disease-free survival in patients with pT2-T4 or node-positive UTUC. The preferred regimen is gemcitabine-cisplatin, or gemcitabine-carboplatin for cisplatin-ineligible patients. This trial has changed clinical practice, making adjuvant chemotherapy the standard of care for high-risk UTUC following surgery. Additionally, adjuvant immunotherapy with nivolumab has shown benefit in high-risk urothelial carcinoma, including UTUC, as demonstrated in the CheckMate 274 trial. ### Lynch Syndrome Considerations All patients with UTUC should be screened for Lynch syndrome using immunohistochemistry for mismatch repair proteins or germline genetic testing. MSH2 mutations are most commonly associated with UTUC. Lynch-associated UTUC may respond favorably to checkpoint inhibitors due to microsatellite instability-high (MSI-high) status. Identifying Lynch syndrome has important implications for cancer surveillance and family member screening. --- A diagram showing the upper urinary tract with the renal pelvis, ureter, and bladder. The locations of UTUC are highlighted (renal pelvis, proximal/mid/distal ureter) with relative frequency percentages. The radical nephroureterectomy specimen is shown en-bloc with bladder cuff, and the lymph node dissection templates are mapped by tumor location (hilar/para-aortic/paracaval for renal pelvis; common iliac for mid-ureter; pelvic for distal ureter). Surgical anatomy illustration with template color-coding. A treatment algorithm for UTUC stratified by risk. Low-risk UTUC branches to kidney-sparing options (ureteroscopic ablation, mitomycin gel instillation, segmental ureterectomy) with intensive surveillance. High-risk UTUC branches to neoadjuvant cisplatin-based chemotherapy (if eligible) followed by radical nephroureterectomy with bladder cuff and lymph node dissection, then adjuvant therapy (POUT trial-based chemotherapy or nivolumab for high-risk pathology). Decision nodes include cisplatin eligibility assessment and Lynch syndrome screening. Clinical algorithm format. --- ## Clinical Pearls During radical nephroureterectomy, excision of the bladder cuff is essential because leaving the distal ureteral stump is associated with high recurrence rates ranging from 30 to 60%. Open bladder cuff excision remains the gold-standard technique due to superior oncologic outcomes. Neoadjuvant chemotherapy should be strongly considered before nephroureterectomy in high-risk UTUC, as cisplatin eligibility significantly declines after removal of the ipsilateral kidney. The POUT trial is a landmark study establishing adjuvant platinum-based chemotherapy as the standard of care for patients with pT2 or higher stage or node-positive UTUC, making it a high-yield topic for board examinations. Mitomycin gel (Jelmyto) facilitates kidney-sparing management of low-grade UTUC but carries a substantial risk of ureteral stricture, occurring in approximately 40% of cases; patients should be counseled accordingly. Screening all UTUC patients for Lynch syndrome, particularly for MSH2 mutations, is critical due to implications for both patient management and family member surveillance. Diagnostic ureteroscopy may underestimate tumor grade in up to 30% of cases; therefore, if clinical suspicion for high-grade disease remains despite a low-grade biopsy, the tumor should be treated as high-risk. Finally, a single intravesical chemotherapy instillation after radical nephroureterectomy reduces the risk of subsequent bladder cancer recurrence and should be incorporated into the perioperative management pathway. --- ## References - Roupret M, et al. EAU Guidelines on Upper Urinary Tract Urothelial Carcinoma. Eur Urol. 2023;83(1):49-64 - Birtle A, et al. Adjuvant chemotherapy in upper tract urothelial carcinoma (POUT). Lancet. 2020;395(10232):1268-1277 - Kleinmann N, et al. Primary chemoablation of low-grade UTUC using UGN-101 (mitomycin gel — OLYMPUS). J Urol. 2020;203(6):1084-1090 - Margulis V, et al. Outcomes of radical nephroureterectomy: a series from the UTUC Collaboration. Cancer. 2009;115(6):1224-1233 - NCCN Clinical Practice Guidelines in Oncology: Bladder Cancer (includes UTUC), Version 3.2024