Upper Urinary Tract Tumors

• Urothelial tumors are neoplastic growths that affect the lining of the urinary tract from the calyces to the distal ureter

Key Features of Upper Urinary Tract TCCs

• Multiplicity
• Recurrent and Metachronous tumors
• Common with poor survival
• Synchronous or metachronous tumor of the ipsilateral or contralateral collecting system are also common

Epidemiology

• 5-10% of urothelial carcinomas are upper tract tumors
• Pyelocaliceal tumors are twice as common as ureteral tumors
• Concurrent bladder cancer occurs in 8-13% of cases
• Recurrence of disease in bladder after UUT-UC is 30-51%
• UUT-UC recurrence in contralateral UT is 2-6%
• Peak age of onset: 70-80 years
• Mean age of presentation: 65 years
• Male-to-female ratio is 3:1
• More common in White individuals than Black individuals by 2:1

Risk Factors Specific to UUT-UC

• Analgesic Abuse: 3.6X risk, with a 2-year latency period; etiology includes Phenacetin, Aspirin, Codeine, P’mol. Histologic findings are B. Membrane thickening (pathognomonic) and Papillary Scarring
• Balkan Nephropathy: Degenerative interstitial nephropathy in Balkan countries like Serbia, Croatia, Romania, and Bulgaria, increases UUT-UC risk by 100-200X, tumors typically are low grade, multiple or multifocal, and bilateral; Etiology: Aristolochic acid is the carcinogenic agent in Aristolochia fangchi and Aristolochia clematis, causes a specific mutation in the p53 gene at codon 139, poorer outcomes are seen with women, Size > 3 cm and Stage T3 or T4 disease
• Papillary Necrosis: 6.9X risk, Synergistic with Analgesic Abuse (20X risk)
• Chinese Wt Loss Herb: Aristolochic acid in Aristolochia fangchi plant, similar nephropathy to Balkan's
• Arsenic Exposure (Blackfoot Disease): Excess arsenic in drinking water in southwestern Taiwan is associated with peripheral vascular disease like Blackfoot disease that causes dry gangrene, also associated with female predominance inhaling cooking fumes
• Previous Bladder UC: 2-4% lifetime risk UUT-UC, high risk if recurrent CIS or CIS refractory to BCG, Multiple Tumours (Multifocal), Vesicoureteral Reflux, High Tumour Stage/Grade or Invasive Dx, Tumours close to ureteric orifice

Other Risk Factors

• Smoking: Principal exogenous risk factor that increases the relative risk of developing a UUT-UC from 2.5 to 7, declines partially after smoking ceases, smoking leads to ureteral tumors rather than renal pelvic tumors
• Contralateral UUT-UC: 1.6-6% risk, risk factors shared with bladder cancer
• Occupational Exposure increases risk of UUT-UC "amino tumours" from occupational exposure (coal, petroleum, asphalt, or tar industries) to certain aromatic amines including Benzidine, β-Naphthalene, and Aniline dyes, Average duration of exposure needed to develop UUT-UC is around 7 years, Latency period of about 20 years after termination of exposure, increased risk with aromatic amines exposure is 8.3.
• Cyclophosphamide Therapy is an increased risk with alkylating agents, Mesna (Uroprotectant) co-administration neutralizes Acrolein
• Chronic Inflammation / Infection Development of Squamous Cell Cancer and adenocarcinoma relate to bacterial infection with urinary stones and obstruction, Epidermoid carcinoma is associated with chronic inflammatory and infectious disease from stones in the UUT

Genetics of UUT-UC

• SULT1A12: Differences in the ability to counteract carcinogens may contribute to host susceptibility to urothelial carcinomas; genetic polymorphisms increase cancer risk or faster disease progression; variability among people; A variant allele, SULT1A12, reduces sulfotransferase activity
• Lynch II Syndrome (HNPCC) is an autosomal-dominant syndrome and Lynch I Syndrome is familial colon cancer, patients are younger than 60 years typically, more likely to be female, and has a personal or any family history of an HNPCC, in HNPCC, an inherited mutation of MMR genes is a critical factor, genetic counselling is advocated

Associated Conditions

• Bladder TCC develops after UUT-UC in 30-51% of cases
• Inverted Papilloma carries a 18% risk of malignancy

Tumor Location and Distribution

• Located more commonly in the Renal Pelvis instead of Ureter in ratio of 3:1
• Renal TCC arises in the extrarenal part of the pelvis, then the infundibulocaliceal region
• Equal distribution b/n left and right kidneys, 2–4% of cases occur bilaterally
• Ureteral tumors: 70% occur in distal ureter, 25% in the mid-ureter, 5% in the proximal
• 30-50% risk of developing bladder TCC after UUT-UC (metachronous bladder involvement)
• Theories for metachronous bladder involvement : Downstream seeding, Exposure to carcinogens, Greater number of urothelial cells in the bladder are subject to random carcinogenic events
• Upper tract urothelial cancers occur as frequently invasive and poorly differentiated compared to bladder

Muscle Invasion Progression

• A thin muscle layer of the renal pelvis and ureter probably allows early penetration of invasive tumors
• Renal parenchyma may be a barrier to the spread of stage T3 cancers
• Periureteral tumor extension is a risk factor for early tumor dissemination
• 60% of UUT-UCs are invasive at diagnosis compared with 15% of bladder tumours

Patterns of Spread

• Direct Invasion into the renal parenchyma or surrounding structures
• Epithelial Spread is the clonal nature of urothelial tumors of the bladder and upper tract is explained via monoclonality or field theory, with evidence supporting monoclonality; Epithelial spreading occurs in both antegrade (most common) and retrograde manners
• Lymphatic Spread: Para-aortic, Paracaval, Ipsilateral Common Iliac, and Pelvic Lymph Nodes
• Haematogenous Spread: Most common sites are the liver, lung, and bone, Direct extension into renal veins and IVC may occur in renal pelvic tumors (very rare)

Histological Subtypes

• Urothelial Carcinoma: >85% tumours; papillary or sessile lesions; may be unifocal or multifocal
• Squamous cell cancers are associated with chronic inflammation/infection; 6X more frequent in renal pelvis than the ureter; moderately/poorly differentiated and invasive
• Adenocarcinomas associated with obstruction, inflammation, or calculi; present at advanced stages in the ureter
• Epidermoid carcinomas represent 10cm

Lymph Nodes:

• NX: nodes cannot be assessed
• N0: No regional lymph node metastasis
• N1: Metastasis ≤2cm
• N2: Metastasis in a single lymph node measuring 2-5cm or multiple ≤5 cm
• N3: Metastasis measures greater than 5 cm

Metastasis:

• M0: No distant metastasis
• M1: Distant metastasis

WHO Grading

WHO 1973:

• Gx: Grade can't be assessed
• G1: Well differentiated, G2: Moderately differentiated, G3: Poorly differentiated or undifferentiated

WHO 2004:

• Papillary urothelial neoplasia of low malignant potential, Low-grade carcinomas, High-grade carcinomas
• There are almost no tumours of low malignant potential in the upper urinary tract

Prognostic Factors

• Tumour architecture is papillary vs sessile with prognosis after RNU, a sessile growth pattern is associated with worse outcomes
• There is Associated CIS in patients that presents poorer outcomes of UUT-UC, similar to bladder carcinoma, predicts of worse outcomes
• Lymphovascular Invasion is present in 20% of UUT-UCs, predictor of survival, in patients with negative lymph nodes, LVI provides prognostic information

Other prognostic factors include:

• Tumour Necrosis
• Patient Age
• Molecular Markers
• Microsatellite Instabilities (MSIs)
• E –cadherin
• Hypoxia-inducible factor (HIF)-1α and telomerase RNA component
• p53

Clinical History

15% of instances are Asymptomatic

• Localized symptoms include Gross/Microhematuria (70%), Dysuria, Flank Pain (20%) and Lumbar Mass (10%)
• Advanced symptoms include Weight loss, Fatigue, Anemia, Bone pain, Anorexia, Malaise, Fever, Night sweats, or Cough

Imaging

• Ultrasound (USS) to confirm presence of solid mass
• C. Urography (CT IVP) for calculi detection, TCC identification
• MRI usage for patients that cannot take MDCTU

Diagnostic Procedures

• Cystoscopy and Urine Cytology for Concomitant bladder TCC
• Retrograde Pyelogram (RP) to identify tumors and collection of urine
• Ureteroscopy with Biopsy to explore ureter and take sample for diagnosis

Treatment

Conservative Treatment:

• Indications are small unifocal grade tumours

Ureteroscopy / Ureteropyeloscopy:

• Lower morbidity and shorter hospital stay
• Limitations in size and sampling

Percutaneous Approach

Indications:

• upper tract access when prior treatments have failed