EUTOS score predicts long-term outcome but not optimal response to imatinib in patients with chronic myeloid leukaemia

Abstract

To test the recently developed EUTOS score in predicting optimal response to imatinib and the long-term outcome, 265 patients with early chronic phase chronic myeloid leukaemia treated with standard dose imatinib were analysed. Achievement of optimal response endpoints were higher in low-risk patients, though the difference was not statistically significant: PCyR at 6th month 86% vs 67% (p=0.06), CCyR at 12th month 80% vs 63% (p=0.09), MMR at 18th month 61% vs 36% (p=0.11). However, EUTOS score was predictive for the long-term response. With a median follow-up of 61 months, 53% high-risk patients experienced imatinib failure, compared to 23% in the low-risk group (p=0.013). Among high-risk patients, 4/17 (23%) progressed to accelerated/blastic phase or died, compared to 11/248 (5%) low-risk patients, with 5-year progression-free survival rates of 84±10% and 96±1%, respectively (p=0.04). Our data confirm that EUTOS score envisions the long-term outcome of imatinib therapy.

Keywords: Chronic myeloid leukaemia; EUTOS score; Imatinib; Prognosis.