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Recurrence After Endoscopic Management of Upper Tract Urothelial Carcinoma: Incidence, Predictors, and Clinical Consequences in an International Multicenter Cohort

In an international multicenter cohort of 277 patients, high-grade biopsy histology was identified as the strongest independent predictor of recurrence following endoscopic management of upper tract urothelial carcinoma, occurring in 34.7% of cases and guiding the need for intensified surveillance and potential delayed radical nephroureterectomy.

Original authors: modassar awan, maida bada, mohammad jaabou, osama zaytoun, ahmed rabie, dovey zachary, paolo gontero, ryan stevens, luca sarcinelli, rocco papalia, stefano signore, alberto martini, massimiliano di ma

Published 2026-06-30

📖 4 min read☕ Coffee break read

CC BY 4.0

Original authors: modassar awan, maida bada, mohammad jaabou, osama zaytoun, ahmed rabie, dovey zachary, paolo gontero, ryan stevens, luca sarcinelli, rocco papalia, stefano signore, alberto martini, massimiliano di marco, roberto giulianelli, alberto pansadoro, rosario leonardi, maurizio buscarini

Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

The Big Picture: Saving the Kidney vs. The "Weed" Problem

Imagine your body is a garden, and the Upper Tract Urothelial Carcinoma (UTUC) is a specific type of stubborn weed growing in the pipes that drain your kidney.

For a long time, the standard way to get rid of this weed was to pull out the entire pipe and the flower pot (the kidney) attached to it. This is called a Radical Nephroureterectomy. While it guarantees the weed is gone, you lose a kidney, which is a big deal if you only have one, or if you are older and need to save your kidney function for other treatments later.

In recent years, doctors have started using a "gardening tool" approach instead. They use a flexible scope (like a tiny camera on a snake) to go inside the pipe and zap the weed with a laser. This is Endoscopic Management. It saves the kidney, but the paper asks a crucial question: Does the weed grow back?

What the Study Did

The researchers gathered data from 277 patients across five different hospitals (in Italy, Spain, and the US) who had this "laser gardening" treatment between 2019 and 2023. They followed these patients for about four years to see what happened.

Think of this study as a long-term observation of a garden where they tried to just trim the weeds instead of ripping out the whole plant.

The Main Findings

1. The Weed Does Come Back (But It's Not a Disaster)

The study found that 35% of the patients (about 1 in 3) saw the weed grow back in the same pipe, the bladder, or the other side.

The Analogy: If you have a garden and you spray weeds, about one-third of the time, a new sprout appears later.
The Good News: Just because the weed came back, it didn't mean the garden was ruined. Most of the time, the doctors could just go back in with the laser and trim it again. Only 11% of patients (about 1 in 9) eventually needed to have the whole pipe and kidney removed.

2. The "High-Grade" Warning Sign

The researchers looked at many factors to see what predicted the weed coming back: How big was the weed? Was there more than one? Was the patient sick with other things? Did the pipe look swollen?

They found that only one thing really mattered: The biopsy grade (what the weed looked like under a microscope).

The Analogy: Imagine you are looking at a dandelion. Some dandelions are just fluffy and harmless (Low Grade). Others are aggressive, deep-rooted monsters (High Grade).
The Result: If the initial biopsy showed the weed was "High Grade" (aggressive), the patient was 3 times more likely to see it come back.
What didn't matter as much: Surprisingly, the size of the weed or having multiple weeds didn't predict the return as strongly as the type of weed did.

3. Recurrence $\neq$ Failure

A major point of the paper is changing how we think about the weed coming back.

Old Thinking: "Oh no, the weed grew back. The treatment failed. We must cut out the whole kidney."
New Thinking: "The weed grew back. That's common. Let's just trim it again."
The Takeaway: The paper argues that recurrence is not a failure. It is a common event that can often be managed without losing the kidney. It's like a garden that needs a little more maintenance, not a garden that needs to be bulldozed.

The Conclusion in Plain English

If you have a specific type of kidney cancer and your doctor suggests using a laser to save your kidney instead of removing it:

Be prepared: There is a good chance (about 1 in 3) that the cancer will show up again later.
Check the "Type": The most important thing to know is whether the cancer cells look "aggressive" (High Grade) under a microscope. If they do, you need to be extra careful and watchful.
Don't Panic: If it comes back, it usually doesn't mean you lose your kidney. Most people can be treated again with the same laser method.

In short: Saving the kidney is a great option, but it requires a "gardener's mindset"—you have to be ready to do a little weeding now and then, especially if the weed is the aggressive kind.

Technical Summary: Recurrence After Endoscopic Management of Upper Tract Urothelial Carcinoma

Problem Statement
Upper tract urothelial carcinoma (UTUC) represents 5–10% of urothelial cancers and carries inherent risks of recurrence, progression, and cancer-specific mortality. While radical nephroureterectomy (RNU) with bladder cuff removal has historically been the standard of care, it results in the loss of a renal unit, potentially compromising renal function and limiting eligibility for systemic therapies in patients with comorbidities, solitary kidneys, or bilateral disease. Consequently, kidney-sparing endoscopic management (ureteroscopic or percutaneous) has gained adoption, particularly for low-risk disease and imperative indications. However, recurrence remains the primary limitation of this approach, with reported rates ranging from 25% to 60%. A critical gap exists in defining the predictors of recurrence and understanding the clinical consequences of recurrence in contemporary practice. Specifically, it is unclear whether recurrence should be viewed as a treatment failure or a manageable event, and which clinicopathologic variables most robustly predict recurrence-free survival (RFS) in a multicenter setting.

Methodology
This study employed a retrospective multicenter cohort design involving 277 consecutive patients treated with primary endoscopic management for localized UTUC between January 2019 and December 2023. The cohort was drawn from five tertiary referral institutions: three in Italy, one in Spain, and one in the United States.

Inclusion/Exclusion: Patients were included if they had pathologically confirmed UTUC treated with kidney-sparing endoscopic management and at least one postoperative follow-up. Exclusion criteria included metastatic disease at presentation, prior RNU, immediate salvage RNU within three months, or missing baseline characteristics.
Data Harmonization: A single locked dataset was created after data harmonization and quality control.
Variables: Baseline variables included age, sex, BMI, Charlson Comorbidity Index (CCI), eGFR, smoking status, history of bladder cancer, tumor size, location, multifocality, hydronephrosis, urinary cytology, and biopsy grade.
Outcomes: The primary endpoint was any recurrence (ipsilateral upper tract, bladder, or contralateral upper tract). Secondary endpoints included clinical progression, delayed RNU, metastatic progression, overall survival, and cancer-specific survival.
Statistical Analysis: Continuous variables were reported as medians with interquartile ranges (IQR); categorical variables as frequencies. Comparisons utilized Mann–Whitney U tests, $\chi^2$ , or Fisher's exact tests. Recurrence-free survival (RFS) was estimated via Kaplan–Meier analysis with log-rank statistics. Univariable and restricted multivariable Cox proportional hazards models were performed. The multivariable model was restricted to clinically relevant baseline variables (biopsy grade, tumor size, multifocality, hydronephrosis, symptomatic presentation, and prior bladder cancer) to prevent overfitting. Analyses were conducted using STATA version 18.0.

Key Contributions
The study provides a contemporary, international assessment of recurrence patterns and predictors following endoscopic UTUC management. Its primary contributions include:

Quantification of Recurrence: Establishing a recurrence rate of 34.7% over a median follow-up of 48.5 months.
Predictor Validation: Identifying high-grade biopsy histology as the dominant and strongest independent predictor of recurrence, outperforming other variables such as tumor size, multifocality, and hydronephrosis in multivariable analysis.
Clinical Consequence Analysis: Demonstrating that while recurrence increases the likelihood of progression and delayed RNU, the majority of recurrent cases remain amenable to further kidney-sparing treatment, challenging the notion that recurrence equates to treatment failure.
Methodological Rigor: Utilizing a single locked dataset across five international centers to ensure reproducible analyses and focusing on clinically relevant endpoints like delayed RNU rather than just recurrence incidence.

Results

Cohort Characteristics: The median age was 73.6 years; 62.5% were male. High-grade biopsy histology was present in 33.2% of cases, 27.8% had multifocal tumors, and 52.0% exhibited hydronephrosis.
Recurrence Incidence: Recurrence occurred in 96 patients (34.7%). The most common phenotype was ipsilateral upper tract recurrence.
Oncologic Outcomes: Progression of grade/stage occurred in 10.8% of patients. Delayed RNU was required in 11.2% (31 patients). Metastatic progression occurred in 3.2% (9 patients), and there were 3 cancer-specific deaths.
Predictive Analysis:
- Univariable Analysis: High-grade biopsy pathology was strongly associated with recurrence (HR 3.27, 95% CI 1.91–5.60; p<0.001). Positive high-grade cytology, multifocality, tumor size >2 cm, and symptomatic presentation were also significant.
- Multivariable Analysis: High-grade biopsy histology remained the only robust independent predictor of recurrence (adjusted HR 3.27, 95% CI 1.91–5.60; p<0.001). While tumor size, multifocality, and hydronephrosis showed trends toward significance in univariable analysis, they did not remain independently predictive after adjustment.
Survival Curves: Kaplan–Meier analysis showed a significant separation in RFS curves based on biopsy grade (log-rank p<0.001), with high-grade tumors demonstrating inferior RFS. Differences based on tumor size and multifocality were numerically present but less distinct and showed significant overlap in confidence intervals.

Significance and Claims
The paper claims that recurrence following endoscopic management of UTUC is common but heterogeneous and should not be synonymous with treatment failure. The authors assert that:

Recurrence is Manageable: Despite a ~35% recurrence rate, only 11.2% of patients required delayed RNU, and most recurrent tumors could be successfully managed with repeat endoscopic interventions without immediate loss of renal function.
Biopsy Grade is Paramount: High-grade biopsy histology is the dominant predictor of recurrence and adverse outcomes. This finding suggests that biopsy grade should guide surveillance intensity and patient counseling more heavily than other factors like tumor size or multifocality.
Re-evaluation of Risk Stratification: The study suggests that current risk stratification schemes relying heavily on tumor size (>2 cm) may be insufficient for predicting recurrence in kidney-sparing contexts, as biopsy grade proved significantly more predictive.
Clinical Implication: Clinicians should anticipate recurrence when offering kidney-sparing management to appropriate patients but should counsel them that recurrence does not inevitably lead to cancer-specific mortality or the loss of the renal unit. The findings support the continued use of kidney-sparing strategies, provided that high-risk features (specifically high-grade histology) are identified and managed with appropriate surveillance.

The authors acknowledge limitations including the retrospective nature of the study, potential selection bias, lack of standardized surveillance protocols across centers, absence of central pathology review, and the unavailability of molecular biomarkers. They conclude that while recurrence is frequent, it is a manageable aspect of the disease course rather than a definitive failure of the endoscopic approach.