Chromosomal abnormalities in childhood acute lymphoblastic leukemia (ALL) are well-established prognostic markers and useful tools for minimal residual disease (MRD) assessment. This study aimed to stratify high-risk precursor B-childhood ALL (pre-B-ALL) patients according to standard prognostic factors (age and total leucocytic count), fluorescence in situ hybridization (FISH) analysis for these cytogenetic abnormalities [t (9;22) BCR/ABL, t(1;19)TCF3/PBX1, and 11q23 MLL gene rearrangement], and MRD status at day 15. Besides, we aimed to demonstrate the relation of these prognostic factors (standard and cytogenetic risk groups) to patients’ outcome at day 15 of induction therapy as well as exploring the impact of early MRD assessment during remission induction compared to other prognostic factors together with the ability to tailor investigations as needed especially in places with limited health resources without compromising the outcome. Seventy-two newly-diagnosed Egyptian children with pre-B-ALL, aged 6 months to 15.5 years, registered from February 2016 to February 2018 were included. They were treated according to the modified Children’s Oncology Group (COG) protocol. Patients were classified into (a) standard and high-risk groups according to standard prognostic factors. (b) Patients with the studied cytogenetic abnormalities and patients without the studied cytogenetic abnormalities. (c) Good outcome (negative MRD) and bad outcome (positive MRD) groups according to day 15 MRD status. The studied cytogenetic abnormalities were identified in 22.2% of patients, all of them were in the high-risk group, and 75% of them had a bad outcome (positive MRD) at day 15 of induction therapy. Patients with favorable presenting features (standard risk) and undetectable MRD after 2 weeks remission induction therapy would not be in need to advanced molecular studies, while these studies should be considered for patients with high-risk presenting features and high levels of MRD after 2 weeks remission induction therapy. Therefore, this could provide a cost-effective guideline in countries suffering from financial challenges without affecting the outcome

中文翻译：

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早期 B 型儿童急性淋巴细胞白血病第 15 天早期微小残留病检测的临床影响：埃及经验

儿童急性淋巴细胞白血病 (ALL) 的染色体异常是公认的预后标志物，也是评估微小残留病 (MRD) 的有用工具。本研究旨在根据标准预后因素（年龄和总白细胞计数）、荧光原位杂交 (FISH) 分析对这些细胞遗传学异常 [t (9 ;22) BCR/ABL、t(1;19)TCF3/PBX1 和 11q23 MLL 基因重排]，以及第 15 天的 MRD 状态。此外，我们旨在证明这些预后因素（标准和细胞遗传学风险组）与诱导治疗第 15 天患者结果的关系，并探讨与其他预后因素相比，缓解诱导期间早期 MRD 评估的影响以及根据需要调整调查，尤其是在卫生资源有限的地方，而不影响结果。包括 72 名新诊断的埃及前 B-ALL 儿童，年龄 6 个月至 15.5 岁，登记时间为 2016 年 2 月至 2018 年 2 月。他们根据修改后的儿童肿瘤学组 (COG) 协议进行治疗。根据标准预后因素将患者分为（a）标准组和高危组。(b) 具有研究的细胞遗传学异常的患者和没有研究的细胞遗传学异常的患者。（ c ）根据第 15 天 MRD 状态的良好结果（阴性 MRD）和不良结果（阳性 MRD）组。在 22.2% 的患者中发现了所研究的细胞遗传学异常，他们都属于高危组，其中 75% 的患者在诱导治疗的第 15 天出现不良结果（阳性 MRD）。具有良好表现特征（标准风险）且在 2 周诱导缓解治疗后检测不到 MRD 的患者不需要进行高级分子研究，而对于具有高风险表现特征和 2 周后 MRD 水平高的患者，应考虑进行这些研究缓解诱导治疗。所以，