How this instrument works
This calculator implements the EORTC risk tables for non-muscle-invasive (Ta/T1) bladder cancer, published by Sylvester and colleagues in European Urology in 2006 from a combined analysis of 2,596 patients across seven EORTC trials. Six clinical factors — number of tumors, tumor size, prior recurrence rate, T category, concurrent carcinoma in situ, and tumor grade — are scored twice, once against a recurrence point table (0 to 17) and once against a separate progression point table (0 to 23), because the same six factors predict recurrence and progression to a more advanced stage with different strength. Concurrent CIS, for example, adds only 1 point toward the recurrence score but 6 points toward the progression score, since carcinoma in situ is a comparatively weak recurrence predictor but a much stronger predictor of progression specifically.
One thing worth stating plainly: the exact point values used here were cross-checked across multiple secondary clinical sources — published guideline summaries and derivative calculators that reproduce the EORTC tables — rather than transcribed directly from Sylvester et al.'s original paywalled European Urology article, which this project could not access in full. The six-factor structure, the two separate point tables, and the resulting risk tiers all match the widely-cited 2006 tables as reproduced in the secondary literature, but anyone using this for clinical decisions should cross-reference against a current guideline source rather than treating this page as the primary citation.
In 2021, the EAU Non-Muscle-Invasive Bladder Cancer Guidelines Panel published an updated prognostic factor risk-group system (Sylvester et al., European Urology, 2021) that some clinicians now use instead of, or alongside, the original 2006 EORTC tables — it isn't implemented here, but it's worth knowing a more current alternative exists. This calculator is a clinical reference tool meant for urologists and oncology teams counseling patients on follow-up cystoscopy schedules and treatment intensity for non-muscle-invasive bladder cancer, not a self-assessment tool for patients to interpret without a clinician.
- Select Number of tumors: 1 tumor, 2-7 tumors, or 8 or more tumors.
- Select Tumor size: less than 3cm or 3cm or more.
- Select Prior recurrence rate: primary (first occurrence), ≤1 recurrence per year, or >1 recurrence per year.
- Select T category: Ta or T1.
- Set Concurrent carcinoma in situ (CIS) to Yes or No.
- Select Tumor grade (G1, G2, or G3), then read the recurrence score and tier and the progression score and tier.
Worked example — three tumor profiles
A single tumor under 3cm, a first occurrence (no prior recurrence), Ta stage, no concurrent CIS, and grade 1: every factor scores 0 on both tables, giving a recurrence score of 0 and a progression score of 0 — the lowest tier (tier 0 of 3) on both scales.
Eight or more tumors, 3cm or larger, more than one recurrence per year, T1 stage, concurrent CIS, and grade 3 scores 6+3+4+1+1+2 = 17 on the recurrence table (the maximum) and 3+3+2+4+6+5 = 23 on the progression table (also the maximum) — the highest tier, tier 3, on both scales. Notice the CIS weight differs: 1 point toward recurrence versus 6 points toward progression, since CIS predicts progression far more strongly.
A moderate case — 2 to 7 tumors, 3cm or larger, up to one recurrence per year, Ta stage, no CIS, and grade 2 — scores 3+3+2+0+0+1 = 9 for recurrence (tier 2 of 3) and 3+3+2+0+0+0 = 8 for progression (also tier 2), even though grade 2 itself contributes 1 recurrence point but 0 progression points, since only grade 3 counts toward the progression table.
Questions
Why are there two separate scores instead of one?
Because recurrence (the tumor coming back) and progression (the tumor advancing to a more invasive stage) are different clinical events with different underlying risk factors, even though both are predicted from the same six inputs. The EORTC tables weight each factor differently for each outcome — concurrent CIS, for instance, adds only 1 point toward recurrence risk but 6 points toward progression risk — so a patient can land in a low recurrence tier while sitting in a higher progression tier, or vice versa.
Where do these exact point values come from?
They're drawn from Sylvester et al.'s 2006 European Urology paper, a combined analysis of 2,596 non-muscle-invasive bladder cancer patients across seven EORTC trials. The specific point values used here were cross-checked against multiple secondary clinical sources and guideline summaries that reproduce the original EORTC tables, since the primary journal article itself sits behind a paywall this project could not access directly — worth knowing if you want to trace the numbers back to the original publication yourself.
Is there a more current version of this risk tool?
Yes. In 2021, the EAU Non-Muscle-Invasive Bladder Cancer Guidelines Panel published an updated prognostic factor risk-group system that some clinicians now use instead of, or alongside, the original 2006 EORTC tables. That 2021 revision is not implemented in this calculator, which reproduces the original 2006 tables — worth flagging as a caveat if you're using this for a current clinical decision rather than as a reference point.
Can a patient use this tool to assess their own bladder cancer risk?
This is built as a clinical reference tool for urologists and oncology teams discussing follow-up cystoscopy schedules and treatment intensity with a patient, not a self-assessment tool for patients to interpret on their own. The six inputs — tumor count, size, prior recurrence pattern, T category, CIS status, and grade — come from pathology and cystoscopy findings a clinician would document, not information a patient would typically self-report accurately.
What do the four risk tiers mean?
Each of the two scores (recurrence 0-17, progression 0-23) maps to its own four-tier risk band, from tier 0 (lowest) to tier 3 (highest). The tier boundaries differ between the two scales — recurrence tiers break at 0, 1-4, 5-9, and 10-17, while progression tiers break at 0, 1-6, 7-13, and 14-23 — because the two outcomes were derived and calibrated separately in the original EORTC analysis.
What six inputs does the calculator use?
Number of tumors (1, 2-7, or 8 or more), tumor size (under 3cm or 3cm or more), prior recurrence rate (primary, up to 1 per year, or more than 1 per year), T category (Ta or T1), concurrent carcinoma in situ, and tumor grade (G1, G2, or G3). All six feed into both the recurrence and progression point tables.
References
- Sylvester RJ, et al. — EORTC risk tables for stage Ta T1 bladder cancer, Eur Urol, 2006;49(3):466-477
- Sylvester RJ, et al. — 2021 EAU prognostic factor risk groups for NMIBC, Eur Urol, 2021;79(4):480-488
Read this first: This instrument computes a screening figure from population formulas — it is not a diagnosis, and it cannot see the whole picture a clinician can. Use it to inform a conversation, not to replace one.