LONG-TERM OUTCOMES OF CHILDHOOD ACUTE LYMPHOCYTIC LEUKEMIA (ALL) TREATED
WITH MODIFIED BERLIN-FRANKFURT-MÜNSTER (BFM) PROTOCOLS IN RIO DE
JANEIRO, BRAZIL: A MULTICENTRIC HOSPITAL-BASED SURVIVAL ANALYSIS STUDY
Abstract
Background/Objectives Acute lymphocytic leukemia (ALL) is the
most common pediatric cancer, more incident in Hispanics. The
Berlin-Frankfurt-Münster (BFM) protocol for ALL began to be used in
hospitals from Rio de Janeiro in the 1980’s. The aim of this study was
to determine survival probabilities and prognostic factors for children
and adolescents with ALL in the state of Rio de Janeiro (RJ) and to
compare these results with other BFM studies. Design/Methods We
conducted a survival analysis study with a retrospective cohort of 695
patients aged from zero to 19 years treated with a modified BFM
protocols between 1998 and 2018 in four reference hospitals in RJ.
Prognostic factors included age, sex, leukocyte count, early response to
treatment and cytogenetic risk. The cohort was divided into two periods.
We calculated the five- and ten-years event-free survival (EFS), the
overall survival (OS) and performed a multivariate analysis using Cox
proportional hazards models. Results In the 1
st period the five-year EFS was 50.3% (±3.0) and the
OS was 61.5 (±2.9). These rates for high-risk patients (HR) were 33.4%
and 47.7%, respectively. In the 2 nd period, the
five-year EFS was 61.6% (±2.8) and the OS was 70.5% (±10.6). These
rates for HR patients were 57.9% and 63.8%. In the cohort, 51.2% of
patients were HR based on BFM classification, 54.7% were HR based on
the National Cancer Institute classification, 27.1% had a leukocyte
count greater than 50,000 and 28.6% were aged less than one or greater
than 10 years. Conclusions Our results led us to hypothesize
that delays in treatment, overestimated risk classification on the 8
th day of treatment and/or unique genetic features of
our population may be causing a higher leukocyte count at the time of
diagnosis and an increased prevalence of HR classification compared to
other BFM studies mainly composed by Caucasians.