EUTOS score is not predictive for survival and outcome in patients with early chronic phase chronic myeloid leukemia treated with tyrosine kinase inhibitors: a single institution experience.

To validate the recently reported European Treatment and Outcomes Study (EUTOS) score, we applied it to 465 patients with early chronic phase chronic myeloid leukemia treated with standard-dose imatinib (n=71), high-dose imatinib (n=208), or second-generation tyrosine kinase inhibitors (n=186), and assessed its ability to predict event-free survival (EFS), transformation-free survival (TFS), and overall survival (OS). The median follow-up was 69 months. The overall complete cytogenetic response and major molecular response rates were 92% and 85%, respectively. The 3-year EFS, TFS, and OS rates were 86%, 95%, and 97%, respectively. Of the 465 patients, 427 (92%) were in low EUTOS score category. There was no difference in the major molecular response, TFS, EFS, and OS rates between patients with low and high EUTOS score, overall and within specific therapies. In conclusion, 8% of patients with chronic phase chronic myeloid leukemia treated at our institution are in the high EUTOS score; in this population, the EUTOS score was not predictive for outcome.