METHODS
We gathered medical records of a total of 101 patients with BL who were treated in our center retrospectively
and assessed for laboratory findings, clinical characteristics, prognostic factors and treatment
protocols.
RESULTS
We found that, nowadays, intra-abdominal presentation of BL was seen more frequently than past at our
center in Turkey. However, there was no statistically significant difference. BL was numerically meaningful.
Murphy"s treatment protocol was more satisfactory compared to past treatment protocols.
CONCLUSION
Our comparison of the previous and present features of patients showed that there is a shift away from the
jaw to mostly intra-abdominal disease presentation at our center, like Uganda, in the course of time. And
we also have a large number of patients and the follow-up period is very long (median 111 months for all
patients) in the literature. We think that the intra-abdominal component is seen more in our geography with
time, but it should be evaluated with more studies in other geographies, especially in Europe and America.
Keywords: Burkitt lymphoma; childhood; epidemiology; treatment
Previous studies from Turkey showed that Turkish
BL appears in a form that is between the endemic and
the sporadic form. A recent study showed that there
are some changes in the endemic form in Uganda over
time.[
We considered complete remission (CR) as the disappearance
of all tumor masses confirmed by clinical
examination and imaging investigations. Progressive
disease (PD) was defined as the tumor site and other
pathological findings showed no decrease after the initiation
of treatment. The reappearance of lymphoma
with the same histological or immunophenotypic features
after achieving CR or PR was considered as Relapse.
Event-free survival (EFS) was defined as the time
from the initial treatment to the time of progression,
relapse, death or the recent follow-up examination. The
overall survival (OS) was considered from the initiation
of treatment to death or the last follow-up examination.[
Statistical Methods
χ2 test or Fisher's Exact Test were used to examine the
differences in the distribution of individual parameters
among patients. The prognostic factors were assessed
using the Kaplan-Meier method. Statistical significance
between treatment protocols was assessed using the
Anova test. Mann-Whitney U and T-tests were used to
compare nonparametric continuous variables. Survival
analyses were compared using the log-rank test and
survival curves were generated with the Kaplan-Meier
method. Multivariate analysis using Cox proportional
hazard regression method was completed to determine
the independent prognostic factors influencing EFS.
All calculations were obtained using SPSS version 15.0
statistical software.
The mean age was 6.5 years (range of 2.6-14 years) and 6.2 years (range of 2.7-14.3 years) in the GRAB group and Murphy group, respectively. The male-to-female ratio was 3.7:1 and 1.8:1 in the the GRAB group and Murphy group, respectively. The most common primary tumor site was abdomen in two groups (42 patients, 80.7% in the GRAB group and 43 patients, 87.8 % in the Murphy group). While 10 of the 52 patients had combined jaw and abdomen presentation in the GRAB group, three of 49 patients had combined jaw and abdomen presentation in the Murphy group. Just one patient had only jaw involvement and he is in the Murphy group. Considering 14 patients with jaw presentation in all patients, no BM involvement was present in them and five of them (35.7%) had a detectable CNS involvement. In addition, four of five patients who had CNS involvement were in the GRAB group, so they had been diagnosed in former times.
While there was no bone marrow (BM) involvement and four patients (7.7%) had CNS involvement in the GRAB therapy group, there were three patients (6.1%) who had BM involvement and four patients (8.2%) had CNS involvement in the Murphy therapy group. According to the St. Jude staging system, 46 patients (88.4%) and 45 patients (91.8%) were in advanced stages (III-IV), in GRAB and Murphy group, respectively.
In the GRAB group, 17 patients died due to progressive disease (n=12), tumor lysis (n=2), sepsis (n=2), and Steven Johnson Syndrome (n=1). Also, in Murphy group, eight patients died due to progressive disease (n=6), sepsis (n=1), and measles pneumonia (n=1). While the follow-up period was 0.5-249 months (median 156 months) for the GRAB group, the followup period was 4-152 months (median 85 months) for the Murphy group.
While there were 18 relapses and 28 remissions in
the GRAB therapy group, there were three relapses and
40 remissions in the Murphy therapy group. The situation
and survival rates of the patients are shown in
Table
Between the two groups, there was no statistically significant difference in age, gender, serum WBC and serum hemoglobin levels, stages, CNS and BM involvements. CNS and BM involvements did not have an effect on prognosis. The decrease in jaw presentation or the increase of intra-abdominal presentation was not statistically significant (p>0.5), but it was numerically meaningful. Studies with a larger number of patients are needed.
Only chemotherapy protocol was found to be a significant factor for prognosis. When chemotherapy protocol groups were compared with EFS and OS values, we found statistically significant differences (p=0.01, p=0.04). In univariate and multivariate analysis, GRAB protocol was found to be an important reverse predictor factor for OS and EFS (p=0.002). Also, at the multivariate analysis, the patients were applied GRAB protocol had seven times more death risk than the group who received Murphy's protocol.
We followed up the patients for mean 104.50±78.65 months (1-249 months) and 74.38 % of them were in remission. While the follow-up period was 0.5-249 months (median 156 months) for GRAB group, the follow- up period was 4-152 months (median 85 months) for the Murphy group.
Previous studies from Turkey showed that Turkish
BL appears in a form that is between the endemic and
the sporadic form. The study conducted by Ogwang et
al. has reported that there are some changes in the endemic
form in Uganda over time [
BL is often seen in boys. According to the literature,
the sporadic form is more prevalent in male and older
age than the endemic form. We observed that, nowadays,
there was a decrease about age and male sex while
comparing with the previous studies from our country
[
The primary intra-abdominal presentation is approximately
80% in the sporadic form [
As there was an increase in the rate of BM involvement
in time, progression to the sporadic form was observed
in our study. In the literature, it was reported that
the involvement of the jaw with CNS involvement was
more frequently in endemic form. In our study, the jaw
presentation with CNS involvement was higher in the
GRAB group, but it was decreasing in the course of time.
The majority of the patients in Murphy group
(91.8%) were detected in the advanced stage like the Burkittsporadic
form (70-78.7%) [
Initial LDH and Hgb levels (LDH>500 U/L and
Hgb<10 mg/dL) in BL are considered as poor prognostic
criteria, even affecting staging. However, in our patients,
no correlation was determined between Hgb, LDH,
WBC levels and the prognosis of patients. The LDH level
is very important. However, we did not compare LDH
levels because there were missing results about our past
data. We think that this arises from the incomplete data
of some of the patients. Patients with BL are reported to
be generally ex due to tumor lysis, renal failure, sepsis
and disease progression. Murphy treatment group"s results
were more favorable than GRAB. Thus, progression
and relapse rates were seen less frequently. The results of
our study were better than the results of Murphy"s own
study. The tumor lysis-related mortality rates were less
frequently observed, which may be due to the better
conditions of care than the previous conditions.
In the course of time, EFS and OS have increased
by the use of short-term and intensive chemotherapy
protocols.[
Limitations
We had to compare our findings only with Ogwang et
al."s study since, to our knowledge, there are no other
studies in the literature apart from Ogwang et al."s
study. Also, the LDH level is very important. However,
we did not compare LDH levels, because there were
missing results about our past data.
Previous studies from Turkey showed that Turkish
BL appears in a form that is between the endemic and
the sporadic form. A recent study conducted by Ogwang
et al. reported that there are some changes in the
endemic form in Uganda over time [
Peer-review: Externally peer-reviewed.
Conflict of Interest: No conflict of interest was declared by
the authors.
Ethics Committee Approval: Ethics committee consent
was obtained from the Dr. SUCH ethics committee.
Financial Support: The authors declared that this study has
received no financial support.
Authorship contributions: Concept - E.B.; Design - C.B.;
Supervision - N.Y.; Funding - None; Materials - E.B.; Data
collection and/or processing - E.B.; Data analysis and/or interpretation
- E.B.; Literature search - S.İ.Ö.; Writing - E.B.;
Critical review - G.Ş.