Incidences and outcomes of therapy-related chronic myeloid leukemia in the era of tyrosine kinase inhibitors: Surveillance of the CML Cooperative Study Group

- The clinical entity of therapy-related CML (TR-CML) is investigated.
- Patient characteristics between de novo CML and TR-CML groups are similar.
- Patients with TR-CML could achieve good treatment response with TKI.
- Clinical outcome is favorable when treated with TKI.

This study was performed to investigate the features and outcome of patients with therapy-related chronic myeloid leukemia (TR-CML) who were treated with tyrosine kinase inhibitors (TKIs). The analysis included 308 patients with CML in the chronic phase who were extracted from the CML Cooperative Study Group database. Of these patients, 11 (3.6%) were identified as having TR-CML. No differences in age, sex, white blood cell count, hemoglobin level, platelet count, or European Treatment and Outcome Study risk were observed between patients with TR-CML vs. de novo CML. However, the responses of TR-CML patients to TKIs (6, 3, and 2 received imatinib, nilotinib, and dasatinib, respectively) were excellent; all achieved major or deep molecular response. Furthermore, the outcomes of TR-CML patients were relatively favorable; the 3-year event-free survival rates in the TR-CML and de novo CML patients were 100% and 94%, respectively; the difference was not statistically significant. In conclusion, our study showed that TR-CML patients could achieve a good clinical course with TKI therapy. Detailed investigations of TR-CML may provide new insights into CML biology.