Introduction:
T-cell acute lymphoblastic leukemia (T-ALL) accounts for 15% of newly
diagnosed cases of childhood acute lymphoblastic leukemia (ALL).
Historically, T-ALL has had inferior event-free survival (EFS) and
overall survival (OS) compared with precursor B-cell ALL (B-ALL).
Patients with T-ALL often present with unfavorable clinical features,
including older age, higher white blood cell count (Wbc), and
extramedullary disease, especially in the central nervous system.
Additionally, T-ALL was reported to have increased risk of induction
failure.
[1-4]
Outcomes for T-ALL have improved with contemporary risk and
response-based treatment protocols: Early intensified therapy, with a
4-drug induction containing dexamethasone and an anthracycline followed
by augmented BFM-like consolidation containing cyclophosphamide,
asparaginase and methotrexate (MTX), but relapse rates remain higher and
relapses often unsalvageable. [5-13]
The outcome of children and adolescents with T-ALL treated at our center
per modified St. Jude total XV regimen was reported in 2014; the
5-year-OS and EFS for Early T-cell precursor acute lymphoblastic
leukemia (ETP)were 77.1% and 79.6%; while for non-ETP, these estimates
were 78.5% and 65.2%,
respectively.[14]
In an attempt to improve the outcome of our patients we modified our
regimen by using an early intensive post-induction chemotherapy composed
of fludarabine, high dose cytarabine and etoposide. This approach was
inspired by the augmented therapy in European protocols for high-risk
leukemia.
[7,
15]
We report here our results using both regimens (standard and augmented)
in children and adolescents who presented to our center with untreated
T-ALL over a period of over 16 years.