Immunophenotypic and age patterns of childhood acute lymphoblastic leukemia in Saudi Arabia

Improved Outcomes of Childhood Acute Lymphoblastic Leukemia: A Retrospective Single Center Study in Saudi Arabia

Objective:

Understanding the clinical and genetic characteristics of pediatric acute lymphoblastic leukemia (ALL) patients may help assigning the appropriate treatment. This study aims to understand patients’ characteristics, “real-world” treatment practice and outcomes of pediatric ALL.

Methods:

A cohort of 213 pediatric ALL patients, treated at (King Faisal Specialist Hospital and Research Center –Jeddah branch) KFSH and RC-J during the period of January 2002 to December 2015 were analyzed retrospectively. Statistical analyses were performed on patients’ demographic, clinical and genetics characteristics and outcomes of different treatment protocols. Survival was evaluated using Kaplan-Meier method, and differences in survival were tested using Log-Rank. Significance was set at 0.05 level.

Results:

Median age of the study cohort was 5 years (range 0.5–15 years) with 55.4% of male population. Majority of the patients had pre-B-cell ALL (88.7%), WBC count <50, 000/µL at diagnosis (76.1%, median = 13.5/µL with a range of 0.51–553.0/µL) with involvement of central nervous system (CNS) disease in 8.5%patients.Different common chromosomal anomalies or abnormalities, including t(12, 21) translocation, MLL genre arrangements, trisomy (4, 10, 17)and others, were detected. Early response to the risk-directed treatment received by the patients (91.1% achieving <5% blast in the bone marrow) as well as the end of induction outcome (96.2%) was encouraging.

Conclusion:

We found that the patients’ clinical characteristics and distribution of genetic abnormalities were similar to those of the western countries. Our findings show that the earlier gap between the western countries and KSA in terms of survival has been closed and that competitive outcomes can be achieved with local infrastructure.

Improved outcome for children with acute lymphoblastic leukemia after risk-adjusted intensive therapy: a single-institution experience

BACKGROUND AND OBJECTIVE

Because of the need for more comprehensive information on the least toxic and most effective forms of therapy for children with acute lymphoblastic leukemia (ALL), we reviewed our experience in the treatment of children with ALL at King Faisal Specialist Hospital and Research Centre (KFSH&RC) and King Fahad National Center for Children's Cancer and Research (KFNCCC&R) over a period of 18 years with a focus on patient characteristics and outcome.

METHODS

During the period of 1981 to 1998, records of children with ALL were retrospectively reviewed with respect to clinical presentation, laboratory findings, risk factors, stratification, therapy and outcome. The protocols used in treatment included 4 local protocols (KFSH 81, 84, 87 and 90), and subsequently, Children's Cancer Group (CCG) protocols, and these were grouped as Era 1 (1981-1992) and Era 2 (1993-1998).

RESULTS

Of 509 children with ALL treated during this period, 316 were treated using local protocols and 193 using CCG protocols. Drugs used in Era 1 included a 4-drug induction using etoposid (VP-16) instead of L-asparaginase. Consolidation was based on high dose methotrexate (MTX) 1 g/m(2) and maintenance was based on oral mercaptopurine (6-MP) and MTX with periodic pulses using intravenous teniposide (VM-26), Ara-C, L-asparaginase, adriamycin, prednisone, VP-16 and cyclophosphamide. International protocols were introduced in Era 2, which was also marked by intensification of early treatment, a wider selection of cytoreductive agents, and the alternating use of non-cross-resistant pairs of drugs during the post-remission period. The end-of-induction remission rate improved from 90% in Era 1 to 95% in Era 2, which was of borderline statistical significance (P=.049). The 5-year event-free survival (EFS) improved from 30.6% in Era 1 to 64.2% in Era 2 (P<.001). Improvement in outcome was achieved without any significant increase in morbidity or mortality, due to improvement in both systemic therapy and supportive care. The most important independent prognostic factors were intensity of therapy, poor risk category assignment and CNS disease at diagnosis.

CONCLUSION

Outcome in children with ALL has improved because of intensification of treatment protocols and better supportive care.

Immunological subtypes of childhood acute lymphoblastic leukemia in Bulgaria

With regards to the geographical variation in acute lymphoblastic leukemia (ALL) distribution, we present data from the immunophenotyping of 171 newly diagnosed cases of childhood ALL in Bulgaria during a 4 year period (1990-1994). On the basis of 17 phenotypic markers the distribution of immunological subtypes was as follows: AUL 4%; Pro-B ALL 13%; common ALL 42%; Pre-B ALL 11%; B-ALL 1%; T-ALL 28% and unclassified 2%. Most of the cases were between 2 and 5 years of age. Common ALL was predominant (53%) in this age group. The male:female ratio was 1.7:1. The frequency of T-ALL (28%) was significantly higher (P < 0.01; t = 3.49) in comparison to that reported for the U.S.A. and West European countries (mean 13%). It was close to the frequency reported by some authors for France (20%), Greece (26%) and south Italy (28.1%). These countries and Bulgaria might form an environmental area with a moderate frequency of T-ALL.

Immunophenotyping of acute leukemia at King Faisal Specialist Hospital and Research Centre

During a 20 month period, 133 bone marrow samples from an equal number of patients with acute leukemia were immunophenotyped. Patients ranged in age from two to 68 years with a mean of 23 years. Eighty-four (63.2%) were classified as acute lymphocytic leukemia (ALL) with the following immunologic subclassification: common ALL 83.3%, T-cell ALL 11.9%, null-cell ALL 2.4% and 2.4% differentiated B-cell ALL. Twenty-eight cases (21%) were classified as acute myeloid leukemia (AML) and 16 cases (12%) demonstrated biphenotypic features. Concordance with morphology and cytochemistry was observed in 129 cases (97%). Four cases (3%) manifested discrepancy between immunophenotyping, morphology and cytochemistry. We conclude that immunophenotyping by flow cytometry is a useful and reliable method for classification of acute leukemia, especially when interpreted in the light of morphology and cytochemistry.

Immunophenotyping of childhood acute lymphoblastic leukemia in Saudi Arabia: second look

Geographical variations in the incidence of disease are of considerable theoretical and practical importance. It has been claimed that the distribution of acute lymphoblastic leukemia (ALL) phenotypes in Saudi Arabia is different from that recorded in the Western literature. One hundred and twelve (112) patients under 15 years of age, diagnosed as ALL between January 1992 and May 1994 had immunophenotypes performed on their blast cells. Common ALL (cALL) together with pre-B-ALL, formed 86.5% of the total; B-cell 3%, T-cell 6% and null cell 4.5%. These figures are not significantly different from the Western literature. A previous claim from this institution in 1990, that both null and B-cell ALL were significantly increased compared with elsewhere, is not supported by the present figures. Age and sex distribution, and FAB classification, L1 77%, L2 20% and L3 3%, were also of the same order as described elsewhere and, in particular, there was no increase in the frequency of L3 subtype.