Refining risk stratification in paediatric B‐acute lymphoblastic leukaemia: Combining IKZF1plus and Day 15 MRD positivity

• Published in: British journal of haematology 2024-04, Vol.204 (4), p.1344-1353
• Main Authors: Liu, Hsi‐Che, Huang, Ying‐Jung, Jaing, Tang‐Her, Wu, Kang‐Hsi, Chen, Shih‐Hsiang, Wang, Shih‐Chung, Yeh, Ting‐Chi, Hsiao, Chih‐Cheng, Chang, Te‐Kau, Yen, Hsiu‐Ju, Huang, Fang‐Liang, Lin, Pei‐Chin, Hou, Jen‐Yin, Sheen, Jiunn‐Ming, Liao, Yu‐Mei, Chang, Tsung‐Yen, Chen, Yu‐Chieh, Chiou, Shyh‐Shin, Yang, Chao‐Ping, Pui, Ching‐Hon, Liang, Der‐Cherng, Shih, Lee‐Yung
• Format: Article
• Language: English
• Subjects: Acute lymphoblastic leukemia; childhood; IKAROS; Leukemia; minimal/measurable residual disease; Pax5 protein; Pediatrics; Survival
• ISSN: 0007-1048; 1365-2141
• DOI: 10.1111/bjh.19338

Summary This study investigates the potential utility of IKZF1 deletion as an additional high‐risk marker for paediatric acute lymphoblastic leukaemia (ALL). The prognostic impact of IKZF1 status, in conjunction with minimal/measurable residual disease (MRD), was evaluated within the MRD‐guided TPOG‐ALL‐2013 protocol using 412 newly diagnosed B‐ALL patients aged 1–18. IKZF1 status was determined using multiplex ligation‐dependent probe amplification. IKZF1 deletions, when co‐occurring with CDKN2A, CDKN2B, PAX5 or PAR1 region deletions in the absence of ERG deletions, were termed IKZF1plus. Both IKZF1 deletion (14.6%) and IKZF1plus (7.8%) independently predicted poorer outcomes in B‐ALL. IKZF1plus was observed in 4.1% of Philadelphia‐negative ALL, with a significantly lower 5‐year event‐free survival (53.9%) compared to IKZF1 deletion alone (83.8%) and wild‐type IKZF1 (91.3%) (p