ALBERT

Description: INTRODUCTION. Continously improving results have been obtained during the last two decades in the control of Philadelphia chromosome (Ph’) positive chronic myeloid leukemia (CML). However, the final goal of molecular remission remains difficult to be obtained, even in the imatinib era. AIMS: Evaluation of the rate of long lasting molecular remission (undetectable p210 transcript at RQ-PCR confirmed by NESTED/RT-PCR in at least two subsequent tests performed over a period of 12 months or more) in response to imatinib or to imatinib-IFNa combination employed as first, second or subsequent line of therapy. PATIENTS. Imatinib alone or in combination with IFNa was given as first, second or subsequent line of therapy to a total of 47 patients. In particular, twenty-one patients were treated at the time of diagnosis with imatinib alone (18,G1) or imatinib-pegilated IFN combination (3,G2). Twenty-three additional patients (G3) received imatinib as second line therapy. Finally, 11 patients were treated with the imatinib-IFNa combination as second (5,G4) or third (6,G5) line therapy. In details, G4 consisted of three patients in cytogenetic relapse (3) or no response (2) after first line imatinib (1)or IFNa-ARA-C(1)therapy. All six patients included in G5 were complete kariotypic, but not molecular responder to imatinib given as second line treatment. METHODS. Molecular response was evaluated by NESTED/real-time-PCR (Guo JQ et al.; Leukemia : 2002; 15:2447–53) and real-time quantitative-PCR (Gabert J et al. Leukemia : 2003; 17: 2318–57) time intervals of 3–6 months from the beginning of therapy. RESULTS. A complete molecular remission lasting 12 months or more was obtained in 11 of 42 evaluable patients(therapy duration ≥ 18 mths).The response rate was higher in patients receiving the imatinib-IFNa combination(6/14) than in those given imatinib in monotherapy (5/36).In details, 4/14 and 1/3 patients respectively receiving early imatinib or imatinib-IFNa combination achieved a stable molecular remission. Two to four consecutive negative tests were documented in all five cases over a period ranging from 12 to 19 mths with 4 patients still in continous remission. Furthermore, 1/22 and 5/11 patients obtained a complete molecular response to imatinib given as second line therapy or imatinib-IFNa combination employed as second (4) or third (1) line therapy. Five negative tests were documented over a period of 12 mths in the patient responsive to imatinib monotherapy. Three to 7 negative consecutive tests were obtained during a period of 12 to 36 mths in the remaining five cases while receiving the imatinib-IFN-a combination. At the present time, 5 of these 6 patients are in continous molecular remission. In all molecularly responsive patients, stable molecular remission was usually preceded by a period of fluctuating negative-positive results of NESTED-PCR tests. CONCLUSIONS. It is not possible to achieve any firm conclusion regarding the effect of the imatinib-INFa combination on molecular response because of the small sample size of treated patients. However, our findings suggest an additive effect of imatinib and IFNa in Ph’ clone control as indicated by the improvement of the quality of remission in long lasting kariotypically, but not molecularly responsive patients when this combination therapy was utilized.

Description: Fifty-two kariotypic abnormalities additional to Philadelphia chromosome (Ph’) were documented at the time of diagnosis or during the course of the disease in 114 CML patients. Five were evaluated only once at the time of diagnosis, while 109 were repeatedly studied overtime during a median period of 138 (1–275)months. A clonal evolution was already present at diagnosis (early clonal evolution) in 12, while in 23 patients, it was documented in the course of the disease (late clonal evolution). Simultaneous appearence of multiple chromosome abnormalities (4/12 and 4/23) and a tendency to acquire further alterations (5/12 and 2/23, respectively) were associate with both early and late secondary clones. Partial or complete chromosome losses (-1, -6, 6q-, 7p-, 11q-, 12p-, -14, -16, -17,-18, -21) other than -Y (11 events), + 8 (9) and loss of Y chromosome (8) were the most commonly cytogenetic abnormalities, irrespective of the time of their occurrence. Translocations other than Ph’ (5 events), complex Ph’ translocations (5), duplication of Ph’ (5), single iso(Ph’) (4), duplication of iso(Ph’) (1) or iso17q (2) were found with a decreasing frequency. The type of kariotypic alteration varied with the time of onset. In fact, partial or complete chromosome monosomies and duplication of iso(Ph’) never represented early, but only late events. Duplication of Ph’ was a late (4/5) rather than an early event (1/5). Similarly, the presence of the iso(Ph’) was documented either in early or late clonal evolution in 1 and 3 instances respectively. Furthermore, +8 developed several months after diagnosis in all, but 2 cases. Complex Ph’ translocations or loss of Y chromosome do not correlate with any specific phase of the leukemic course. Cytogenetic abnormalities neither correlated with Sokal risk nor with the type of break-points (b3a2,b2a2) documented at diagnosis. However all 3 clones bearing p230 chimeric protein showed early cytogenetic evolution. Secondary clones seem to have different impact on disease history. The occurrence of partial or complete deletions, the iso17q and the late, but not early, loss of Y chromosome were all predictive of a rapid disease progression. Early secondary clones with additional translocations had no effect on the chronic behaviour of the disease, while such clones were associated with a rapid progression (2/3) to blastic phase when they occurred during the course of disease. The presence of +8 as the sole cytogenetic abnormality and complex translocations, irrespective of the time of their onset, did not correlate with leukemia evolution. Finally,simple Ph’ duplication of or single and double iso(Ph’), when not associated with other cytogenetic abnormalities, did not correlate with an aggressive course, even if it can be assumed that these cytogenetic events are responsible for an increased concentration of the p210 oncoprotein. In conclusion, regardless of whether bcr/abl has a direct or an indirect role in promoting genomic instability, in our cohort of CML patients additional non random chromosomal abnormalities frequently characterize both early and late phase of the disease and some of them may represent crucial steps in development and progression of leukemia.