The rate of complete karyotypic remission (CKR) and complete molecular remission (undetectable BCR/ABL specific transcript by real-time quantitative-PCR (
Gabert J et al.) and NESTED/real-time-PCR (
Guo JQ et al.;)) to various therapies was analysed in 35, of the 114 CML patients observed in our institution, who showed cytogenetic clonal evolution. Overall, 52 karyotypic abnormalities additional to Ph’ were documented at the time of diagnosis (early clonal evolution) or late in the course of the disease (late clonal evolution). Seven of 12 patients with early clonal evolution achieved one (5 pts) or more (2 pts) CKRs, for a total number of 9, in response to IFNα (2 CKRs), IFNα plus ARA-C (1 CKR), imatinib (5 CKRs) or imatinib-IFNα combination (1 CKRs). Six of the 23 patients with late clonal evolution achieved one or more CKRs during the course of their disease after treatment with IFNα (2), IFNa plus ARA-C (1) or imatinib (5). In addition, 7 of the 13 CK responders reached a complete molecular remission in response to IFNa (1), IFNa plus ARA-C (1) imatinib (1), or imatinib plus IFNa (4). The 5 complete molecular remissions documented in patients with early clonal evolution, were observed following treatment with IFNα plus ARA-C (1), imatinib (1), or imatinib plus IFNα (3). Two patients with late clonal evolution obtained complete molecular remission in response to IFNα and imatinib plus IFN therapy, respectively. Cytogenetic and molecular response rates were higher in patients with early (58%, 57%) than in patients with late secondary clones (26%, 33%), while there were no significant differences in time to achieve cytogenetic (2–20 months vs 1–25 months) or molecular (3–26 months vs 13–52 months) remission and the duration of response (11 months, range 4–42 vs 10 months, range 7–46 and 2–19 vs 3–13+ months, respectively) between the two groups. Finally, no relationship was evident between the type of additional karyotypic anomalies and sensitivity to treatment. In fact, clones bearing complex translocations (2), isoPh’ (2), trisomy 8 (2), translocations other than Ph’ (2), partial chromosome monosomy (11-q, 1) or loss of chromosome Y alone (1) or associated with other anomalies (−6 and −14 or −21 or isoPh’) (3) all responded to therapy. In conclusion, although the small sample size, these findings suggest that the presence of karyotypic abnormalities additional to Ph’ in CML is not associated to disease resistance to therapy.
Disclosure: No relevant conflicts of interest to declare.
2006, The American Society of Hematology