EORTC Bladder Cancer Calculator (recurrence & progression risk tables, Ta/T1)

Understanding the EORTC bladder cancer risk calculator — concept and principle

The EORTC risk tables estimate the chance that a non-muscle-invasive bladder cancer (stage Ta or T1) will come back (recurrence) or grow into the bladder muscle (progression) within 1 and 5 years. Urologists use them to choose follow-up intervals and decide on extra treatment after removal of the tumour.

Two separate point totals: with the default inputs the result is 24% / 1% (recurrence / progression, 1 yr).

How it is calculated

Recurrence score (0–17): number of tumours (1 = 0, 2–7 = 3, 8 or more = 6) + diameter 3 cm or more (3) + prior recurrence rate (1 or fewer per year = 2, more than 1 per year = 4) + T1 (1) + concomitant CIS (1) + grade (G2 = 1, G3 = 2).

Progression score (0–23): 2 or more tumours (3) + diameter 3 cm or more (3) + recurrent tumour (2) + T1 (4) + CIS (6) + G3 (5).

Recurrence groups are 0, 1–4, 5–9 and 10–17 points; progression groups are 0, 2–6, 7–13 and 14–23. The calculator shows each group's published probabilities.

The principle

The tables come from 2,596 patients in seven EORTC trials. Each factor received a weight according to how strongly it predicted the outcome. Recurrence depends mostly on how many tumours there are and how often they came back, while progression depends most on CIS, T1 stage and high grade, the signs of aggressive disease.

Worked example

Default inputs: 2 to 7 tumours, under 3 cm, primary, Ta, no CIS, G2.

Recurrence = 3 + 0 + 0 + 0 + 0 + 1 = 4 → group 1–4: 24% at 1 year, 46% at 5 years.
Progression = 3 + 0 + 0 + 0 + 0 + 0 = 3 → group 2–6: 1% at 1 year, 6% at 5 years.

How to read the result

Where does your result fall?

Higher scores mean more frequent cystoscopy and stronger additional treatment are usually considered. Most patients in the original trials did not receive maintenance BCG, so the tables tend to overestimate risk for those who do. Current EAU guidelines also use newer risk groups based on WHO 2004/2016 grading.

Common mistakes

Using the WHO 2004 low/high grade instead of the 1973 G1–G3 grade.
Applying the tables to muscle-invasive (T2 or higher) cancer.
Reading group averages as an exact personal risk.

Keep in mind: This is not a diagnosis or a treatment recommendation. Decisions belong to the urology team, who weigh pathology, treatment and patient factors.

Frequently asked questions

What is carcinoma in situ (CIS)?

A flat, high-grade cancer confined to the bladder lining. It strongly raises the risk of progression.

Why does recurrence matter if it is not invasive?

Each recurrence needs another procedure and may carry a higher grade or stage.

Is there an updated model?

Yes. In 2021 the EAU guidelines panel published new prognostic risk groups that include WHO 2004/2016 grading, and the CUETO score was built in BCG-treated patients.

Sources: Sylvester RJ, van der Meijden APM, Oosterlinck W, et al., "Predicting recurrence and progression in individual patients with stage Ta T1 bladder cancer using EORTC risk tables", Eur Urol 2006;49:466–477

Checked 9 Nov 2026. Sylvester RJ, van der Meijden APM, Oosterlinck W, et al., “Predicting recurrence and progression in individual patients with stage Ta T1 bladder cancer using EORTC risk tables”, Eur Urol 2006;49:466–477 — factor weights as reproduced in Int Braz J Urol (recurrence) and Cent European J Urol (progression); group probabilities (1 and 5 years) as reproduced in Pillai et al., ScientificWorldJournal 2011, Table 4.

Your numbers