MRD LEVEL ANALYSIS IN ADULT ALL PATIENTS. ANALYSIS OF THE CZECH LEUKEMIA STUDY GROUP–FOR LIFE (CELL)

Konference: 2013 18th Congress of the European Hematology Association - účast ČR

Kategorie: Maligní lymfomy a leukémie

Téma: Acute myeloid leukemia - Clinical

Číslo abstraktu: P623

Autoři: MUDr. Mgr. Cyril Šálek, Ph.D.; MUDr. František Folber; MUDr. Eva Froňková, Ph.D.; RNDr. Bohumír Procházka; doc. MUDr. Petr Cetkovský, Ph.D.; prof. MUDr. Jiří Mayer, CSc.; prof. MUDr. Michael Doubek, Ph.D.

Background:

Ninety-two patients with adult ALL were treated in two major centres in the Czech Republic in 2007–2012. Median age at diagnosis was 37.8 mos. Patients ≤55 yrs. of age were treated according to GMALL 07/2003 protocol, treatment of older patients was not standardised. MRD levels were monitored in bone marrow at clearly defined timepoints.

Aims:

o evaluate prognostic impact of MRD load at different timepoints of the therapy on overall suvival (OS).

Methods:

The search for PCR target was performed in 85 pts. PCR marker was found in 78/85 (92%) pts. In 30/85 (35.5%) pts. a fusion gene was found (BCR/ABL in 24 pts., MLL/AF4 in 6 pts.), Ig/TCR rearrangements were monitored in 48/85 (56.5%) pts.. The search for Ig/TCR was undertaken in the group without fusion gene only; the success rate for Ig/TCR detection was 87% (48/55 pts.). MRD negativity (MRDneg) was defined as whatever value <10-4 when outside of quantitative range.

Results:

Patients reaching MRDneg after the first course of chemotherapy (day 26) had 3 yrs. OS 78%, n=30 (vs. 52%, n=37) with median survival not reached (vs. 52 mos.) (P=0.036), median time to relapse was not reached (NR) (vs. 34 mos.) (P=0.012). Patients reaching MRDneg after the second induction therapy (day 46) had 3 yrs. OS 77%, n=44 (vs. 46%, n=24) with median survival not reached (vs. 30 mos.) (P=0.023), median time to relapse was NR (vs. 34 mos.) (P=0.066). Patients who were MRDneg at the beginning of consolidation therapy (after previous 2 induction cycles, week 11) had 3 yrs. OS 80%, n=40 (vs. 48%, n=15) with median survival not reached (vs. 30 mos.) (P=0.007), median time to relapse was NR (vs. 10 mos.) (P<0.001). Of 34 pts. who were indicated to alo-HSCT, 24 pts. were MRDneg prior to HSCT. Three-year-OS in MRDneg group was 82% (vs. 45%), median survival NR (vs. 24 mos.) (P=0.034), median time to relapse was NR (vs. 10 mos.) (P=0.005). All 4 pts. who remained MRDpos after the alo-HSCT relapsed in median of 7 mos (P<0.001); median OS was 22 mos. (P=0.005). The mean time to MRD negativity was significantly longer in BCR/ABL+ ALL (105 days) than in other types of B-ALL (44 days) and T-ALL (56 days) (P=0.002).

Summary and Conclusions:

MRD load after the first induction cycle and at the beginning of consolidation therapy has prognostic significance regarding OS and relapse free survival. MRD load prior to alo-HSCT is of prognostic impact as well. MRDpos status within 3 months after the HSCT defines the group with especially unfavorable prognosis. MRD response in BCR/ABL+ ALL is significantly slower than in other adult ALL subgroups.

Abstrakta v časopise Haematologica 2013, Suppl1

Online Program

Datum přednesení příspěvku: 15. 6. 2013