EORTC Bladder Cancer Calculator — NMIBC Recurrence & Progression Risk
Score six pathological features of a non-muscle-invasive bladder cancer (NMIBC) to estimate 1-year and 5-year probabilities of recurrence and progression to muscle-invasive disease, based on the EORTC risk tables published by Sylvester et al. in 2006.
Number of tumors
Largest tumor diameter
Prior recurrence rate
T category (stage)
Concurrent CIS
Tumor grade (WHO 1973)
Low recurrence risk — 1-yr: 15%, 5-yr: 31%
- 1
Count + size + prior recurrence
0 + 0 + 0 = 0Tumor count (0/3/6), largest diameter (0/3), prior recurrence rate (0/2/4). - 2
T-stage + CIS + grade
0 + 0 + 0 = 0T category (0/1), concurrent CIS (0/1), grade G1/G2/G3 (0/1/2). - 3
EORTC recurrence score
0 + 0 = 0
How does this calculator work?
Six pathological factors (tumour count, size, prior recurrence rate, T stage, CIS, grade) are weighted and summed to produce an EORTC recurrence score (0–17) and progression score (0–23). Scores stratify 1-year and 5-year recurrence and progression-to-MIBC rates for NMIBC patients. Based on Sylvester et al. 2006 EORTC trial data (n = 2,596).
Formula
How this is calculated
The European Organisation for Research and Treatment of Cancer (EORTC) published risk tables in 2006 (Sylvester et al., BJU International 98:1078-1086) derived from 2,596 patients with Ta and T1 NMIBC enrolled in seven EORTC trials. Six pathological and clinical factors are weighted and summed to generate two separate scores: a recurrence score (0–17) and a progression score (0–23). The recurrence score stratifies patients into four groups with 1-year recurrence rates of approximately 15%, 24%, 38%, and 61%, respectively; the corresponding 5-year rates are 31%, 46%, 62%, and 78%. The progression score groups patients with 1-year muscle-invasive progression rates of 0.2%, 1%, 5%, and 17%.
The weighting differs between scores. For recurrence, tumour count and prior recurrence rate carry the largest weights (up to 6 and 4 points, respectively). For progression, concurrent carcinoma in situ (CIS) dominates (6 points), followed by T1 stage (4 points) and G3 grade (5 points) — reflecting the known aggressiveness of these features for disease advancement. Prior recurrence rate contributes to the progression score only if greater than 1 per year (2 points).
These risk scores were developed on patients treated predominantly with intravesical chemotherapy before the BCG era, so they may overestimate risk in patients receiving optimal BCG treatment. The 2006 EORTC tables remain the most widely cited reference tool for NMIBC risk stratification, but are intended as clinical decision support — individual patient management should always incorporate endoscopic findings, histopathology details, and specialist judgment.
Frequently asked questions
A recurrence score of 5–9 is classified as high risk (~38% 1-year and ~62% 5-year recurrence rate). A score of 10–17 is very high risk (~61% at 1 year, ~78% at 5 years). Scores of 0 or 1–4 represent low and moderate risk respectively.
The factors that best predict recurrence are not the same ones that best predict progression to muscle-invasive disease. For example, the number of tumours and prior recurrence rate strongly predict recurrence but contribute modestly to progression; concurrent CIS and T1 stage are the strongest drivers of progression risk.
No. The EORTC 2006 tables apply specifically to non-muscle-invasive papillary urothelial carcinoma (stages Ta and T1) without prior muscle-invasive disease or upper-tract involvement. They do not apply to T2 or higher stage, pure CIS, or variant histologies. The model predates widespread BCG use, which may affect calibration in BCG-treated cohorts.
Also known as
TG we-Calculate Editorial Team. (2026). EORTC Bladder Cancer Calculator — NMIBC Recurrence & Progression Risk [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/eortc-bladder-cancer-calculator
TG we-Calculate Editorial Team. "EORTC Bladder Cancer Calculator — NMIBC Recurrence & Progression Risk." TG we-Calculate. 2026. https://we-calculate.com/calculator/eortc-bladder-cancer-calculator.
TG we-Calculate Editorial Team, "EORTC Bladder Cancer Calculator — NMIBC Recurrence & Progression Risk," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/eortc-bladder-cancer-calculator
@misc{wecalculate_eortc_bladder_cancer_calculator, title = {EORTC Bladder Cancer Calculator — NMIBC Recurrence & Progression Risk}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/eortc-bladder-cancer-calculator}}, year = {2026}, note = {TG we-Calculate} }
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