A RARE CASE OF HIGH-RISK ACUTE PROMYELOCYTIC LEUKEMIA WITH T (1; 17) (Q21; Q21)

Hailong Zhai¹, Yufang Wang^{2, *}

¹School of Medicine, Hubei Polytechnic University, Huangshi, Hubei, China - ²Department of Hematology, Huangshi Central Hospital, Edong Healthcare Group(Affiliated Hospital of Hubei Polytechnic University), Huangshi, Hubei, China

Objectives: Acute promyelocytic leukemia (APL) is characterized by t (15; 17) (q24; q21). This translocation results in a PML-RARA fusion gene. To date, 16 cytogenetic variants of APL have been identified, including t (11; 17) (11q23; q12)/PLZF-RARA, t (5; 17) (5q35; q12)/NPM1-RARA, t (11; 17) (q13; q21)/NUMA-RARA, etc. Most of variant APL exhibited resistance to all-trans retinoic acid (ATRA) and arsenic trioxide. Variant APL is subject to relapse and its prognosis is poor. This study aims to present a rare case of high-risk APL with t (1; 17) (q21; q21), which is different from the above APL in karyotypes. APL is characterized by t (15; 17) (q24; q21). This translocation results in a PML-RARA fusion gene. 

Methods: A 49-year-old male suffered fever for five days, strength lacking in his right lower extremity for three days. With bone marrow (BM) aspirate, flow cytometry, RT-PCR and karyotype, the case is diagnosed with variant high-risk APL. The patient received large-dose idarubicin for induction treatment.

Results: The patient achieved complete molecular remission. However, the case relapsed 18 months later, though ARA-C+aclarubicin +granulocyte colony-stimulating factor (GCF) (CAG) +ATRA have been administered to him. CR2 wasn’t achieved. He refused to be transferred to a higher-level hospital and voluntarily gave up all the treatment, then died. 

Conclusion: The present study identified a novel t (1; 17) (q21; q21), a novel variant translocation. High-risk plus the fusion gene PML-RARa (bcr3) might partly contribute to the refractory APL. In many aspects, the high-risk APL with t (1; 17) (q21; q21) showed many characteristics invariant APL. APL with t (1; 17) (q42; q21) is ATO resistance and DNR resistance during induction therapy but can obtain CR1 with large-dose idarubicin. APL with t (1; 17) (q42; q21) is vulnerable to relapse and is hard to obtain CR2. Its prognosis was poor, probably due to its variant karyotype. After CR1 has been achieved, further chemotherapy might be unnecessary and Allo-HSCT might be the only effective therapy to treat it.