Is EUTOS Score Predictive Of Outcome In Patients With Early Chronic Phase Chronic Myeloid Leukemia Treated With Imatinib? Preliminary Data From The National Protocol Of The Chilean Cooperative Group Panda

Before the Tirosine Kinase Inhibitors (TKI) era, the SOKAL and HASFORD scores have been used to predict outcome in chronic myeloid leukemia (CML) patients. The recently reported European Treatment and Outcome Study (EUTOS) score is a simple formula created to identify patients with significantly lower probabilities of responding to therapy and survival. The MD Anderson group didn´t validate this score.

To validate the EUTOS score in our population treated in the public health hospitals in Chile with a single protocol of the cooperative group PANDA.

Patients were selected from the data base of the CML 2007 PANDA protocol. All patients were adults (>15 years old) in early chronic phase and received first-line treatment with imatinib-based regimes and had a minimal follow up of twelve months. Event was defined as not reaching complete cytogenetic response in the first year of treatment, death from any cause at any time, loss of complete hematologic response, loss of major cytogenetic response, or progression to accelerated or blast phase. Overall survival (OS) was defined as death of any cause at any time. Event free survival (EFS) was defined as time from diagnosis to any event.

A total of 78 patients were selected from the 330 patients of the data base. The rest had incomplete data. The median age was 48 (range 16 to 79 years old), 47 men and 31 women. Patients with low EUTOS score were 49 (63%) and 29 (37%) were high. The sensitivity of EUTOS was 46% , the specificity was 71% and the negative predictive value was 68%. There was no significative difference in EFS and OS in both EUTOS groups.

EUTOS score was not predictive of outcome in our patient population. Nevertheless it showed a good negative predictive value meaning that it can only identify low risk patients. This could be used in developing countries to select patients that could use lower cost TKI in first line treatment.

No relevant conflicts of interest to declare.