Περίληψη:
Purpose: Even though acute lymphoblastic leukemia (ALL) responds well to
chemotherapy, relapse remains the major problem. This study documents
relapse and survival rates in 85 consecutive children (33 at good risk,
52 at high risk) with ALL diagnosed in 1991 to 1996.
Patients and Methods: Until 1993, the New York II protocol for the
high-risk group and a combination of UKALL XI (induction) and R blocks
of ALL-REZ BFM-87 (intensification) regimens for patients at good risk
were used. To reduce toxicity, the protocols were subsequently modified.
Consolidation treatment was the same for both groups, consisting of a
lower cytarabine dose and methotrexate removal, whereas intensification
was changed only for the high-risk group using the BB block of the
NHL-BFM-90 protocol. The bone marrow clearance of leukemia was assessed
on day 22, and minimal residual disease was detected using polymerase
chain reaction analysis of Ig heavy-chain gene rearrangements.
Results: Seventy patients had common precursor B lineage ALL, six had
pre-B-ALL, eight had T-ALL, and one had B-ALL. Two patients never
achieved remission and died. Six patients died of consolidation-related
complications. Four more patients died, two during induction and two
during maintenance therapy. Two other children had relapse (2.3%), both
of whom were treated with the earlier protocols and then underwent bone
marrow transplantation. Four more children with morphologically complete
remission showed minimal residual disease (which reached the levels of I
leukemic cell among 10(2)-10(4) normal cells) with the use of
clone-specific probes at several points of the study intervals, but
never had relapse. The 5-year overall and event-free survival rates were
86% and 83%, respectively. The 5-year overall survival rates for
good-risk and high-risk groups were 94% and 81%; the corresponding
event-free rates were 91% and 78%. The 5-year event-free survival rate
in the patients at high risk was significantly higher after the protocol
change (90% vs. 65%, P = 0.04).
Conclusions: The modification proved to be effective in diminishing the
therapeutic toxicity and improving the efficacy, mainly for the
high-risk group.
Συγγραφείς:
Tzortzatou-Stathopoulou, F
Papadopoulou, AL
Moschovi, M and
Botsonis, A
Tsangaris, GT
