Philadelphia-like acute lymphoblastic leukemia: Characterization in a pediatric cohort in a referral center in Colombia.

BACKGROUND: Philadelphia-like (Ph-like) acute lymphoblastic leukemia (ALL) is a subtype of pediatric leukemia with high risk factors and poor outcome. There are few reports of its prevalence in Latin America. AIM: This study evaluated the frequency and clinical and biological characteristics of Ph-like ALL in a pediatric cancer center in Colombia. METHODS: The Ph-like genetic profile was analyzed by a low-density array (LDA). Samples from patients with Ph-like ALL were analyzed by fluorescent in situ hybridization for cytokine receptor like factor 2 (CRLF2) and ABL proto-oncogene 1, non-receptor tyrosine kinase (ABL1) rearrangements. Copy number variations were assessed by multiplex ligation probe amplification. RESULTS: Data from 121 patients were analyzed. Fifteen patients (12.4%) had Ph-like ALL, and these patients had significantly higher leukocyte counts at diagnosis and higher levels of minimal residual disease on days 15 and 33 of induction than patients without the Ph-like subtype. There were no significant differences in sex, age, or response to prednisone at day 8 between the two groups. CRLF2 rearrangements were identified in eight patients, and ABL1 rearrangements were identified in two patients. Other genetic alterations alone or in combination were identified in 77% of patients, including deletions in cyclin dependent kinase inhibitor 2 A/B (46.2%), IKAROS family zinc finger 1 (38.3%), and paired box 5 (30.8%). CONCLUSIONS: Ph-like ALL had a 12.4% prevalence in our cohort of patients with pediatric ALL. The identification of this group of patients has importance for risk stratification and future targeted therapy.

Malignant bone tumors in Pediatrics. Five year experience in a pediatric referral center / Tumores óseos malignos en pediatría. Experiencia de cinco años en un centro de referencia pediátrico

Abstract Background: Osteosarcoma (OS) and Ewing's Sarcoma (ES) are the two most common malignant bone tumors in children. A retrospective review of the records of children diagnosed in a pediatric hospital over a five year period (2008-2013) was performed. Objective: To present the experiences acquired during the treatment of these types of tumors and to compare the results obtained with those reported in the literature. Methodology: The database of the Oncology and Pathology Service of Fundación Hospital de la Misericordia (HOMI) was reviewed to identify patients with primary bone tumors referred for histopathology analysis. Results: 22 patients were diagnosed with OS, with a mean age of 11.9 years. 96% of cases were located in the lower extremities. All patients received neoadjuvant chemotherapy and 86% underwent surgical treatment; 13% survived. 15 patients were diagnosed with ES, with a mean age of 12.4 years. 67% of cases were located in flat bones, 53% of patients had metastasis when diagnosed, and all received neoadjuvant chemotherapy. 40% of patients received surgical intervention and 20% received radiotherapy. Survival at the completion of the reseearch was 33%. Conclusions: Cure and survival rates are lower than those reported in the literature despite efforts to improve treatments.

Resumen Introducción. El osteosarcoma (OS) y el sarcoma de Ewing (SE) son los tumores óseos malignos más frecuentes en edad pediátrica. En el presente estudio se realiza la revisión de los tumores malignos primarios de hueso diagnosticados en un hospital pediátrico de referencia en un período de cinco años (2008-2013). Objetivos. Mostrar la experiencia en el tratamiento de osteosarcomas y sarcomas de Ewing y comparar los resultados con lo reportado en la literatura. Materiales y métodos. Se revisó la base de datos del Servicio de Oncología y Patología de la Fundación Hospital de la Misericordia (HOMI) para identificar los pacientes con tumores primarios de hueso remitidos para estudio histopatológico. Resultados. 22 pacientes con edad promedio de 11.9 años tuvieron diagnóstico de OS; 96% de los casos se localizaron en la extremidad inferior, 100% de los pacientes recibieron quimioterapia neoadyuvante, 86% recibieron manejo quirúrgico y 13% sobrevivieron. 15 pacientes con edad promedio de 12.4 años tuvieron diagnóstico de SE; 67% de los casos se localizaron en huesos planos, 53% de los pacientes presentaron metástasis al diagnóstico, 100% recibieron quimioterapia neoadyuvante, 40% fueron llevados a cirugía y 20% recibieron radioterapia. La sobrevida fue de 33% al finalizar esta investigación. Conclusiones. Las tasas de curación y sobrevida son menores a las reportadas en la literatura a pesar de esfuerzos en mejorar los tratamientos.