The outcome of patients with chronic myeloid leukemia (CML) has improved dramatically following the introduction of tyrosine kinase inhibitor (TKI) therapy.1With TKI treatment, most patients with CML, chronic phase (CML-CP) can achieve complete cytogenetic response (CCyR) within 12 months after initial diagnosis of CML. Thanks to the high sensitivity of molecular methods to detect BCR-ABL1transcripts, deeper molecular responses can now be ascertained, including major molecular response (MMR), MR4 or MR4.5 (4 and 4.5- log reduction of BCR-ABL1fusion transcripts, respectively), and molecularly undetectable leukemia (MUL).2, 3It seems intuitive that the deeper the treatment response, the better the survival of patients with CML-CP is.4, 5 However, multiple studies have shown that deeper responses beyond CCyR confer no survival benefit. Patients with CML-CP who achieve CCyR have a very favorable survival similar to that of the general population.6, 7 In contrast, CML-CP patients who are unable to achieve CCyR have a significantly poorer survival, suggesting that achieving CCyR is essential for predicting a favorable outcome.
https://www.nature.c.../bcj20174a.html
