Prognosis of Second Primary Malignancies in Pediatric Acute Lymphoblastic Leukemia Survivors: A Multicenter Study by the Turkish Pediatric Hematology Society.

The improved survival rates of childhood cancers raise the long-term risk of second primary malignancy (SPM) in childhood and adolescent cancer survivors. The intensity of the treatment protocol used, the use of some groups of chemotherapeutics, and radiotherapy were found to be risk factors for the development of second primary malignancies (SPMs). Forty-one patients who developed acute myelocytic leukemia or any solid organ cancer within 25 years of follow-up, after completion of pediatric acute lymphoblastic leukemia (ALL) treatment, were included in the study. The mean duration of initial ALL diagnosis to SPM was 9.3 ± 6.1 years. The 3 most common SPMs were acute myelocytic leukemia, glial tumors, and thyroid cancer. Thirteen (81%) of 16 patients exposed to cranial irradiation had cancer related to the radiation field. In total 13/41 (32%) patients died, and the 5-year overall survival rate was 70 ± 8%. Patients older than 5 years old at ALL diagnosis had significantly worse overall survival than cases younger than 5 years old. In conclusion, children and adolescents who survive ALL have an increased risk of developing SPM compared with healthy populations, and physicians following these patients should screen for SPMs at regular intervals.

The Outcome of Modified St. Jude Total XV Protocol in Turkish Children with Newly Diagnosed Acute Lymphoblastic Leukemia: A Single-Center Retrospective Analysis.

Objective: This study examines the prognostic factors and outcomes of Turkish children with newly diagnosed acute lymphoblastic leukemia (ALL) who were treated with Modified St. Jude Total XV Protocol, which was modified by adding high-dose methylprednisolone (HDMP) before induction in the original protocol. Materials and Methods: A cohort of 183 newly diagnosed ALL patients aged 1-18 years received Modified St. Jude Total XV Therapy between January 1, 2008 and January 30, 2016. HDMP was administered for 7 days, with randomized doses at 10 or 20 mg/kg/d, tapered during the subsequent 7 days to 5 and 10 mg/kg/d, followed by 2 mg/kg/d for 2 weeks. Absolute blast count in peripheral blood and minimal residual disease (MRD) in bone marrow were assesses at the end of the initial HDMP treatment (Day 7). MRD in the bone marrow was measured on day 15 and at the end of the induction period. These patients were followed until July 15, 2019. Results: The five-year event-free (EFS) and overall survival (OAS) rates for all patients were 85.6±2.6% and 89.2±2.3%, respectively. The steroid good responder rate (<1 000/mm3 absolute blast count in peripheral blood on Day 7) was 88%, with 97% of children achieving complete remission post-induction. No significant differences were observed between the two groups in survival rate and infection frequency. EFS and OAS correlated with initial leukocyte count, age 10-18 years at diagnosis, CD20 positivity at diagnosis, and gram-negative bacterial infection during remission induction. Conclusion: The notable response rates on day 7 and 15, along with encouraging EFS and OAS outcomes with Modified St. Jude Total XV in childhood ALL patients underscore the early and high response effect of HDMP. Short-term HDMP can be initiated at the onset of induction, administered at 10 mg/kg/day for the initial 7 days, aiming to minimize potential side effects.

Myeloid sarcoma with RBM15::MRTFA (MKL1) mimicking vascular neoplasm.

Extramedullary involvement of acute myeloid leukemia (AML), aka myeloid sarcoma, is a rare phenomenon in acute megakaryoblastic leukemia with RBM15:: MRTFA(MKL1) fusion, which might mimic non-hematologic malignancies. A 7-month-old infant presented with leukocytosis, hepatosplenomegaly, multiple lymphadenopathies, and a solid mass in the right thigh. Initially, the patient was diagnosed with a malignant vascular tumor regarding the expression of vascular markers from the biopsy of the right thigh lesion that was performed after the inconclusive bone marrow biopsy. The second bone marrow biopsy, which was performed due to the partial response to sarcoma treatment, showed hypercellular bone marrow with CD34 and CD61-positive spindle cell infiltration and > 20% basophilic blasts with cytoplasmic blebs. RNA sequencing of soft tissue biopsy revealed the presence of RBM15::MRTFA(MKL1) fusion. Based on these findings, myeloid sarcoma/AML with RBM15::MRTFA(MKL1) fusion diagnosis was made. AML with RBM15::MRTFA(MKL1) fusion can initially present as extramedullary lesions and might cause misdiagnosis of non-hematologic malignancies.