Iman Sidhom

False-positive F-18 FDG uptake in PET/CT studies in pediatric patients with abdominal Burkittʼs lymphoma

IntroductionIn pediatric patients with abdominal Burkitts lymphoma, the involvement of the gastrointestinal tract and abdominal lymph nodes are the main presenting feature of the disease. Chemotherapy is the main treatment modality and could be preceded by surgical excision of the abdominal masses. To achieve cure or long-term disease-free survival a balance has to be struck between aggressive chemotherapy and the probability of tumor necrosis secondary to treatment complicated by acute infections, perforation or intestinal bleeding. F-18 fluorodeoxyglucose-positron emission tomography/computed tomography (F-18 FDG-PET/CT) has been recommended over conventional imaging modalities for the follow-up of these patients and for monitoring treatment response. As the incidences of postchemotherapy complications are high, the positive predictive value of PET/CT studies in these patients is very low and the false-positive rate is high from acute infections and tumor necrosis. Accordingly, histopathological confirmation of positive lesions on F-18 FDG-PET/CT studies is essential. This is especially important as post-therapy complications might present with nonspecific and nonurgent symptoms. At the same time initiating a second course of salvage chemotherapy is risky. Aim of studyRetrospectively reviewed F-18 FDG-PET/CT studies for 28 pediatric patients with abdominal Burkitts lymphoma and diffuse large B-cell lymphoma after their treatment with chemotherapy or surgery. ResultsFour positive studies were found. All had pathological verification and were because of acute inflammation and tumor necrosis and there was no evidence of viable tumor cells. One patient had multiple recurrent lesions in the abdomen after the initial surgical excision and before starting chemotherapy. The incidence of acute complications in this series is 10.7%. ConclusionThis study confirms the high incidence of tumor necrosis and inflammation after chemotherapy for the abdominal Burkitts lymphoma and consequently, the incidence of true-positive F-18 FDG studies is low. This necessitates the need for histopathological confirmation of positive studies.

NKX2‐5, SIL/TAL and TLX3/HOX11L2 expression in Egyptian pediatric T‐cell acute lymphoblastic leukemia

Cohorts of T‐cell acute lymphoblastic leukemia (T‐ALL) patients show regional geographic differences in incidence, biological features and clinical outcome, implying that in different populations, cases may harbor different genetic lesions than those reported elsewhere. In this study, we prospectively evaluated the frequency and the clinical relevance of NKX2‐5, TLX3/HOX11L2 and SIL/TAL expression in Egyptian childhood T‐ALL.

Clinical significance of anaplasia in childhood rhabdomyosarcoma.

BACKGROUND The presence of anaplastic features has been known to correlate with poor clinical outcome in various pediatric malignancies, including Wilms tumor and medulloblastoma but not in rhabdomyosarcoma. AIM Aim was to study the frequency of anaplasia at presentation in childhood rhabdomyosarcoma and its relationship to clinical and pathological characteristics as well as to outcome. PATIENTS AND METHODS Anaplasia was retrospectively assessed in 105 consecutive pediatric rhabdomyosarcoma patients who were registered at the Childrens Cancer Hospital in Egypt (CCHE) during the period from July 2007 till the end of May 2010. RESULTS Anaplasia was diagnosed in 18 patients (17.1%), focal in 10 (9.5%) and diffuse in 8 (7.6%). The distribution of anaplasia was found to be more common in older patients having age⩾10 years. Also it was more likely to occur in the high risk group and in tumors with unfavorable histology (alveolar subtype), and stage IV. The 3-year failure free survival rates for patients with and without anaplasia were 27.8±10.6% and 53.4±5.8%, respectively (p=0.014) and the 3-year overall survival rates were 35.3±11.6% and 61±6%, respectively (p=0.019). CONCLUSIONS The frequency of anaplasia in pediatric patients with rhabdomyosarcoma in our study was 17.1%. The presence of anaplasia had statistically significant worse clinical outcome.

Osteonecrosis in children with acute lymphoblastic leukemia: A report from Children's Cancer Hospital Egypt (CCHE)

As survival rates for children with acute lymphoblastic leukemia (ALL) improve, awareness of treatment complications becomes important. Osteonecrosis (ON) is a serious disabling complication in treated ALL patients. The aim of the study was to define the frequency of ON identified by magnetic resonance imaging (MRI) and to study the risk factors for ON.

Abstract B07: Prevalence of the most common fusion gene transcripts in 1080 Egyptian pediatric acute lymphoblastic leukemia patients: Children Cancer Hospital Egypt (CCHE) experience.

Introduction: Childhood acute lymphoblastic leukemia (ALL) is a highly heterogeneous disease with distinct biological subgroups. Objective: To detect the incidence of the most common fusion gene transcripts in a large cohort of de novo Egyptian pediatric precursor B-ALL as well as relapsed cases for the first time in Egypt. To compare our results with other Western and Eastern countries to see if there is ethnic variation. Procedure: The study included 1080 consecutive patients with de novo precursor B-ALL and 58 relapsed cases with age ≤ 18 years that were admitted and treated at Children Cancer Hospital Egypt (CCHE) from July 2007 till December 2013. Diagnosis was established by morphological examination and immunophenotyping. All cases were subjected to cytogenetic and molecular analysis. RT-PCR was carried out to test for the most common fusion gene transcripts t(12;21) ETV6/RUNX1, t(1;19) TCF3/PBX1, t(9; 22) BCR/ABL and t(4; 11) MLL/AF4. Results: Out of 1080 newly diagnosed cases, ETV6-RUNX1 was found in 165 (15.3%), E2A-PBX1 in 74 (6.9 %), BCR-ABL in 41 (3.9%) and MLL-AF4 in 20 (1.9 %). The incidence in relapsed cases was 6.7%, 6.7%, 1.7% and 5.1% respectively. As regards immunophenotyping, ETV6-RUNX1 was highly correlated with CALL, E2A-PBX to Pre-B and MLL-AF4 to Pro-B (p 0.0001, 0.0001, 0.0001) while BCR-ABL was not related to any phenotype. As regarding age, all fusion genes were highly correlated to the age group 1-10 years (p 0.0001, 0.007, 0.0001) except MLL-AF4 was correlated to 0-1 age group (p 0.0001). As regards total leucocytic count (TLC), E2A-PBX1 and BCR-ABL were correlated to 100x103/µl while ETV6-RUNX1 showed no correlation. ETV6-RUNX1 (15.3%) was much lower than that reported by United States and Western Europe that have range 19-26% with a median of 23% while it is nearly comparable with Far East range of 13.4-17.5%. BCR-ABL (3.9%) is a little bit higher than western 2% while lower than Far East 6.65%. E2A-PBX1 (6.9%) was little higher than Western 3-5% and Far East 4.9%. MLL-AF4 1.9% was comparable with both Western and Far East (2-3%). Comparison with Middle East which is of limited number of studies; ETV6-RUNX1 was higher than Iraq, Kuwait, and Jordan 12.1%, 11.7%, 12% but much lower than Saudi Arabia 21%. E2A-PBX1 was much higher than Kuwait, Iraq and Saudi Arabia (1.8%, 4.2%, and 4.2%). BCR-ABL was comparable.MLL-AF4 was comparable with Saudi Arabia (2.5%) but lower than Kuwait and Iraq (3.6%, 4.2%). About relapsed cases, ETV6-RUNX1, BCR-ABL and MLL-AF4 were much lower than Western Europe and Far East. Conclusion: These frequency differences of molecular markers in childhood ALL confirm the Ethnic and geographic variation. Other factors may play a role such as exposure to environmental oncogenic factors and of course differences among laboratories may play part in this difference. So we should put into consideration that this frequency difference may have important implication for prognosis, drug selection and treatment outcome. Citation Format: Dina Yassin, Sonya Soliman, Khaled Shaaban, Sherine Salem, Nayera Hamdy, Hala Reda, Iman Sidhom, Abeer Mokhles, Nesreen Aly, Amr EL Nashar, Wafaa Rashed, Mai Mahmoud, Sarah Hesham, Alaa ELHaddad. Prevalence of the most common fusion gene transcripts in 1080 Egyptian pediatric acute lymphoblastic leukemia patients: Children Cancer Hospital Egypt (CCHE) experience. [abstract]. In: Proceedings of the AACR Special Conference on Hematologic Malignancies: Translating Discoveries to Novel Therapies; Sep 20-23, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(17 Suppl):Abstract nr B07.