چکیده (انگلیسی):

Acute lymphoblastic leukemia (ALL) accounts for about
25% of all childhood ALL. The incidence of ALL is about 4/
100,000 children, 85% of childhood ALL originate from B cell
precursors, and 15% are of T-cell origin. The incidence of
early T cell leukemia (ETCL), a subclass of T-cell acute lymphoblastic
leukemia, varies from 5.5%, as reported by the
Tokyo children cancer study group L99-15 study, to about
16% in the AIEOP-BFM ALL2009 study and the UKALL 2003
protocol [1–3]. Several reports have shown conflicting
results regarding the prognosis of this subtype. Children
with ETCL were treated as T-cell ALL by all groups that
reported on the outcome [1–6].
We retrospectively reviewed 559 pediatric patients with
ALL diagnosed between Jan 2003 and December 2014. T cell
ALL accounted for 82 cases (14.7%). Complete immunophenotypic
data was available for 63 (76.8%). ETCL accounted
for 20.6% (n = 13), and they form the study group (Table 1).
In the non ETCL group; the median age was 9.25
(range 0.58–17.7 years). Males accounted for 70%
(n = 35). Median WBC at presentation was 128.1
103
(range 0.9–467
103). Four patients had CNS II status,
and one patient had CNS III. Forty two patients (84%)
were in remission at day 15 and 49 (98%) were in remission
at end of induction; one patient had undetermined
status. With a median follow up of 21.6 months (range,
0.83–121.9), 5 had relapsed and died because of their
disease, 2 died because of sepsis ,and one due to
unknown cause.
The ETCL group had a median age of 10.8 (range 3.3–
14.4 years). Males accounted for 69% (n = 9). Median WBC
at presentation was 117.6
103 (range 2.7–240
103).
Four patients had CNS II status, and two had CNS III 3.
MRD, status of remission and therapy was administered
according to a modified St. Jude total XV protocol,
detailed of which were published earlier [7]. Nine
patients (69.2%) were in remission at day 15 and twelve
patients (92.3%) were in remission at end of Induction.
At a median follow up of 27.6 months (range 13.9–
93.7), two patients (15.4%) relapsed and died of their
disease (one with BM and CNS relapse, and the second
with BM relapse only. 11 patients (84.6%) remain in
remission.