Background
Acute lymphoblastic leukemia (ALL) is a malignant blood disorder with a
high prevalence in childhood, particularly in pediatric patients with
B-cell ALL (B-ALL)[1]. Due to the continuous
improvement in MICM precise staging and multi-drug combination
chemotherapy regimens, the 5-year overall survival rate (OS) of
pediatric patients with ALL has reached over 90% and the 5-year
event-free survival rate (EFS) has reached
80%[2]. However, conventional chemotherapy has
been shown to be ineffective for very high-risk pediatric patients.
Philadelphia chromosome (Ph)-positive ALL was historically associated
with very poor outcomes before the advent of tyrosine kinase inhibitors
(TKIs)[3]. The long-term survival of pediatric
patients with Ph+ ALL has significantly improved with
the use of regimens combining TKI with chemotherapy. The CCCG-ALL-2015
study showed that the 4-year EFS and OS were 71.0% and 88.4%,
respectively, for pediatric Ph+ ALL patients treated
with TKI[4]. Nevertheless, while severe and
life-threatening cardiovascular events, such as pulmonary arterial
hypertension (PAH), have been reported in adults with chronic myeloid
leukemia (CML) and Ph+ B-ALL patients receiving
long-term TKI therapy[5], they have been rarely
reported in pediatric patients.
This study reports the clinical findings for two pediatric
Ph+ ALL patients who showed PAH as a result of
long-term dasatinib therapy at our department, and also reviews the
relevant literature on the incidence of PAH during the course of
dasatinib treatment.