EUTOS Score Calculator

Prognostic score for chronic myeloid leukemia treated with imatinib

Applies at the time of CML diagnosis, before starting treatment.

1. Calculate EUTOS score

2. Determine risk category and imatinib response rates

EUTOS scoreRisk category18 month CCyR rate*5 year PFS*
≤ 87Low86%90%
> 87High66%82%
* Response rates apply to imatinib treatment


The European Treatment and Outcome Study (EUTOS) risk score for chronic myeloid leukemia (CML) was derived from multivariate analysis of response of 2060 patients treated with imatinib for CML between 2002 and 2006. The score is applied at diagnosis, before starting therapy.1

The EUTOS score is calculated as (7 x basophil) + (4 x spleen), where “basophil” is basophils as a percentage of peripheral blood leukocytes and “spleen” is spleen size palpable below left costal margin.

The EUTOS publication1 also provides the following formula to predict the probability of no CCgR at 18 months: exp(−2.1007 + (0.0700 x basophils) + (0.0402 x spleen size))/(1 + exp(−2.1007 + (0.0700 x basophils) + (0.0402 x spleen size)).