What is the difference between Cx bladder (Cytosponge-based urine test) triage and Cx bladder monitoring for a patient with suspected bladder cancer, history of hematuria, previous bladder cancer, or exposure to carcinogens?

CxBladder Triage vs CxBladder Monitor: Key Differences

CxBladder Triage is used for initial evaluation of patients with hematuria to determine who needs cystoscopy, while CxBladder Monitor is used for surveillance of patients with a history of bladder cancer to detect recurrence.

CxBladder Triage: Initial Diagnostic Evaluation

Primary Indication

• CxBladder Triage is specifically designed for patients presenting with microhematuria who have never had bladder cancer 1
• The test helps risk-stratify patients to determine whether cystoscopy can be safely avoided 1

Clinical Performance

• Negative predictive value of 99-100% (95% CI: 95%-100%) in microhematuria populations, representing the highest quality evidence (AUA Strength of Evidence: Grade A) 1
• This was the only urine-based tumor marker evaluated in a randomized controlled trial comparing marker-based approach versus standard cystoscopy 1
• In intermediate-risk patients (1% pre-test probability), a negative CxBladder Triage reduces post-test probability to 0.1-0.4% 1

Appropriate Patient Population

• Should only be used in intermediate-risk patients with microhematuria 1
• Should NOT be used in low/negligible-risk patients (where cancer risk is already ~0.4% and testing would increase false positives) 1
• Should NOT be used in high-risk patients (where cancer incidence exceeds 2.5% and cystoscopy cannot be safely avoided) 1

Safety Considerations

• One subsequent pTa high-grade bladder cancer was diagnosed 13 months after initial presentation in the RCT, highlighting that negative results require follow-up 1
• Repeat urinalysis within 12 months should be considered for safety, with persistent microhematuria prompting cystoscopy 1
• Must be combined with renal and bladder ultrasound imaging 1

CxBladder Monitor: Surveillance for Recurrence

Primary Indication

• CxBladder Monitor is designed for patients with a history of treated bladder cancer who are undergoing surveillance for recurrence 2
• Used to determine whether surveillance cystoscopy can be safely deferred 2

Clinical Performance

• Negative predictive value of 95.16% in surveillance populations 2
• The test is non-invasive, accurate, and reproducible for ruling out urothelial carcinoma recurrence 2

Appropriate Patient Population

• Patients with previous bladder cancer diagnosis who have been treated 2
• Particularly useful for low-risk patients in surveillance protocols 2
• Should be used in conjunction with upper tract imaging as part of routine surveillance 2

Distinction from Other Surveillance Markers

• Unlike CxBladder Resolve (which has 99.8% NPV but was tested in mixed microhematuria and gross hematuria populations), CxBladder Monitor is specifically validated for the surveillance setting 1, 2
• CxBladder Monitor accounts for different risk factors than Triage, including date of last recurrence rather than type of hematuria 2

Critical Algorithmic Differences

When to Use CxBladder Triage

1. Patient presents with NEW microhematuria (no prior bladder cancer history) 1
2. Risk stratification places patient in intermediate-risk category 1
3. Renal and bladder ultrasound has been performed 1
4. Goal: Determine if initial cystoscopy can be avoided 1

When to Use CxBladder Monitor

1. Patient has HISTORY of treated bladder cancer 2
2. Patient is in surveillance phase 2
3. Upper tract imaging is part of routine protocol 2
4. Goal: Determine if surveillance cystoscopy can be deferred 2

Common Pitfalls to Avoid

Do Not Confuse the Populations

• Never use CxBladder Triage in patients with prior bladder cancer—this is the wrong test for surveillance 1, 2
• Never use CxBladder Monitor for initial hematuria evaluation—it is not validated for this indication 2

Do Not Use as Standalone Tests

• Neither test replaces cystoscopy entirely; they help determine who can safely avoid or defer cystoscopy 1, 2
• Both require imaging (ultrasound for Triage, upper tract imaging for Monitor) 1, 2
• Negative results still require follow-up urinalysis within 12 months for Triage patients 1

Do Not Use in Wrong Risk Categories

• CxBladder Triage should not be used in low-risk or high-risk microhematuria patients 1
• In low-risk patients, the test increases false positives without benefit 1
• In high-risk patients, cystoscopy cannot be safely avoided regardless of test results 1

Evidence Quality Comparison

CxBladder Triage has the strongest evidence base of any urine-based tumor marker, being the only one evaluated in a randomized controlled trial (AUA Grade A evidence) 1. CxBladder Monitor has been validated in prospective single-center studies with excellent negative predictive value 2. However, cystoscopy remains the gold standard with sensitivity of 87-100% and specificity of 64-100% 1, and neither urine test can completely replace it 1, 3, 4.