EORTC Bladder Cancer Recurrence and Progression Calculator

Estimate the risk of bladder cancer recurrence and progression using the EORTC risk tables.

Tumor Characteristics

Number of Tumors Tumor Diameter T Category Tumor Grade (WHO 1973) Concurrent Carcinoma in Situ (CIS)

Patient History Prior Recurrence Rate

Recurrence Risk

15%

1-Year

31%

5-Year

Recurrence Score: 0

Progression Risk

0.2%

1-Year

0.8%

5-Year

Progression Score: 0

Clinical Context: These probabilities are based on the EORTC risk tables for patients with Ta/T1 NMIBC. Higher scores indicate greater risk of recurrence or progression. Always interpret results within the full clinical picture.

Disclaimer: This tool is for clinical reference only and does not replace professional medical judgment. The EORTC tables apply strictly to Ta/T1 NMIBC and not to muscle-invasive disease or primary CIS alone.

What This Calculator Does

This tool calculates the probability of bladder cancer recurrence and disease progression in patients with non-muscle-invasive bladder cancer (NMIBC). It uses the validated EORTC (European Organisation for Research and Treatment of Cancer) risk scoring system, which assigns points based on established clinical and pathological factors to produce 1-year and 5-year risk estimates.

How the EORTC Risk Score Works

The EORTC risk tables were developed from a large cohort of NMIBC patients and are widely used in clinical practice to guide treatment decisions and follow-up schedules. The scoring system evaluates six key factors:

Number of tumors — Single vs. multiple tumors
Tumor size — Diameter less than 3 cm vs. 3 cm or greater
Prior recurrence rate — Number of recurrences per year before the current episode
T category — Ta vs. T1 (depth of invasion)
Grade — WHO 1973 grading (G1, G2, G3) or WHO 2004/2016 grading (low-grade, high-grade)
Carcinoma in situ (CIS) — Presence or absence of CIS

Each factor contributes a specific number of points. The total score corresponds to a risk category (low, intermediate, or high) and provides estimated probabilities for recurrence and progression at 1 and 5 years.

How to Use the Calculator

Select the appropriate values for each clinical factor based on the patient's pathology report and history.
Choose the grading system used in your institution (WHO 1973 or WHO 2004/2016).
Review the calculated total score and the corresponding risk percentages for recurrence and progression.
Use the results alongside clinical judgment and patient preferences when planning surveillance and treatment.

Understanding Your Results

The output displays two separate risk estimates:

Recurrence risk — The probability that the tumor will return within the bladder after initial treatment.
Progression risk — The probability that the disease will advance to muscle-invasive bladder cancer (stage T2 or higher).

Both are presented as percentages for 1-year and 5-year timeframes. Higher total scores indicate greater risk. The EORTC system categorizes patients into three risk groups, which can help determine the appropriate intensity of follow-up cystoscopy and the potential benefit of intravesical therapy.

Important Limitations

The EORTC risk tables were developed from patients treated in the 1980s and 1990s, before the widespread use of modern treatments such as second-generation BCG strains and maintenance BCG therapy. Actual outcomes may differ in contemporary practice.
The model does not account for all prognostic factors, such as lymphovascular invasion, variant histology, or molecular markers.
Risk estimates apply to populations, not individuals. Individual outcomes can vary significantly.
The calculator is a decision-support tool and should not replace clinical evaluation by a urologist or oncologist.

Common Clinical Applications

Determining follow-up cystoscopy frequency (e.g., every 3 months for high-risk patients vs. annually for low-risk patients)
Assessing the need for adjuvant intravesical therapy (BCG or chemotherapy)
Counseling patients about their long-term prognosis
Stratifying patients in clinical trial eligibility assessments

FAQ

What is the difference between recurrence and progression?

Recurrence refers to the return of non-muscle-invasive bladder cancer in the bladder after treatment. Progression means the cancer has advanced to a higher stage, specifically to muscle-invasive disease (T2 or higher), which carries a worse prognosis and typically requires more aggressive treatment such as cystectomy.

Can I use this calculator for muscle-invasive bladder cancer?

No. The EORTC risk tables were designed and validated only for non-muscle-invasive bladder cancer (stages Ta, T1, and CIS). They are not applicable to muscle-invasive or metastatic disease.

Why do I need to choose a grading system?

Pathologists may report tumor grade using either the older WHO 1973 system (G1, G2, G3) or the newer WHO 2004/2016 system (low-grade, high-grade). The EORTC scoring assigns different point values depending on which grading system was used, so selecting the correct one is essential for an accurate risk estimate.

How accurate are the EORTC risk predictions?

The EORTC risk tables are among the most widely validated tools for NMIBC prognosis, but they have limitations. The original study population predates modern BCG maintenance protocols, so the progression risk may be overestimated in patients receiving contemporary treatment. The recurrence risk estimates remain reasonably accurate in most settings.

What should I do if my calculated risk is high?

A high-risk score typically warrants more intensive surveillance and consideration of intravesical BCG therapy. Discuss the results with your urologist, who can interpret them in the context of your overall health, tumor characteristics, and treatment history to develop an appropriate management plan.