Translocation (2;11)(q37;q23) in therapy-related myelodysplastic syndrome after treatment for acute promyelocytic leukemia

CPX-351 and allogeneic stem cell transplant for a therapy-related acute myeloid leukemia that developed after treatment of acute promyelocytic leukemia: a case report and review of the literature

Therapy-related myeloid neoplasms (t-MNs), which develop after cytotoxic, radiation, or immunosuppressive therapy for an unrelated disease, account for 7%-8% of acute myeloid leukemia (AML). Worse outcomes and consequently shortened survival are associated with t-MNs as compared with de novo AML. Therapy-related MNs are being reported with increasing frequency in successfully treated acute promyelocytic leukemia (APL), in particular, before the introduction of all-trans retinoic acid (ATRA) plus arsenic trioxide (ATO). Considering the high curability of APL, t-MNs represent one of the prognosis-limiting factors in this setting of leukemia. We report our experience with a patient who developed t-AML 15 years after treatment for APL. Treatment included three cycles of chemotherapy with CPX-351 (Vyxeos, Jazz Pharmaceuticals) followed, as in remission, by an allogeneic hematopoietic stem cell transplant. A review of available literature was also included.

BCR-ABL1-positive acute lymphoblastic leukemia following successful treatment of acute promyelocytic leukemia: case report

Acute promyelocytic leukemia (APL) is currently considered a disease with a higher cure rate. And cases of secondary malignant tumors following successful APL treatment are rare. Here we described a rare case of a 29-year-old man who was treated for APL in 2019 and developed BCR-ABL1-positive acute lymphoblastic leukemia 2 years later. The patient responded well to tyrosine kinase inhibitors and chemotherapy, and achieved a molecular remission. Although APL usually has a good prognosis, the prognosis of its secondary malignancies is uncertain. There are no effective measures to prevent the occurrence of secondary tumors. Continuing to increase the monitoring frequency of laboratory tests, especially the molecular biomarkers, is essential for the diagnosis and treatment of secondary malignancies after the patients achieving complete remission.

Novel MLL/KMT2A-MON2 fusion in a child with therapy-related acute myeloid leukemia after treatment for acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML), which is characterized by the reciprocal t (15;17) (q24; q21) translocation, resulting in PML-RARA gene fusion. Therapy-related AML (t-AML) is a serious complication after cytotoxic and/or radiation therapy in many malignant diseases. In this report, MLL/KMT2A-MON2, with balanced chromosomal translocation t (11;12) (q23; q14), was identified as a novel fusion in a child transformed to t-AML after successful treatment of APL. This study emphasized that clinical monitoring with an integrated laboratory approach is essential for the diagnosis and treatment of t-AML.

[Therapy-related myeloid neoplasms after successful treatment for acute promyelocytic leukemia: a report of four cases and literature review]

目的

探讨急性早幼粒细胞白血病（APL）患者继发治疗相关性髓系肿瘤（t-MN）的临床特点、诊断、治疗及预后。

方法

回顾性分析中国医学科学院血液病医院2012年10月至2019年1月收治的4例APL继发t-MN患者的临床资料，并进行相关文献复习。

结果

4例APL继发t-MN患者均为女性，中位年龄42（40~53）岁，3例接受了以维甲酸（ATRA）+亚砷酸（ATO）为基础联合蒽环/蒽醌类药物±阿糖胞苷的前期诱导缓解及巩固治疗方案，1例采用了ATRA联合蒽环/蒽醌类药物±阿糖胞苷的治疗方案，均没有使用烷化剂。在APL获得完全缓解（CR）后40~43个月出现t-MN，其中治疗相关性骨髓增生异常综合征（t-MDS）1例，治疗相关性急性髓系白血病（t-AML）3例，出现t-MN时PML-RARα融合基因均为阴性。3例t-AML患者接受了2~4个疗程再诱导治疗，其中有1例t-AML患者在获得CR后行异基因造血干细胞移植（allo-HSCT），1例t-MDS患者接受了去甲基化治疗。中位随访54.5（48~62）个月，2例t-AML患者死亡，出现t-MN后中位生存期为12（5~18）个月。1989至2018年文献共报道63例APL继发t-MN病例，与本次报道的4例汇总分析，67例患者中男27例，女40例；中位年龄为52.5（15~76）岁；中位潜伏期39（12~168）个月，确诊t-MN后中位生存时间为10（1~39）个月。

结论

APL继发t-MN较为少见，目前缺乏有效的防治措施，预后不佳，在随访过程中（尤其是获得CR后39个月左右）若出现病情变化，应警惕t-MN的发生，对此类患者应尽快明确疾病的变化，给予合理的治疗。

Secondary clonal hematologic neoplasia following successful therapy for acute promyelocytic leukemia (APL): A report of two cases and review of the literature

Although rare, secondary clonal hematologic neoplasia may occur after successful therapy for acute promyelocytic leukemia (APL). These secondary clonal events may be considered therapy-related, but may also be due to an underlying background of clonal hematopoiesis from which both malignancies may develop. In this manuscript, we describe two patients with secondary clones after APL therapy characterized in one patient by deletion of chromosome 11q23 and, in the other, by monosomy of chromosome 7, and also provide a review of all secondary clonal disorders described after APL therapy. We suggest that since most reports identify karyotypic abnormalities not typically associated with chemotherapy, there may be another mechanism underlying secondary clonal development after complete response to initial APL therapy.

A complex MLL rearrangement identified five years after initial MDS diagnosis results in out-of-frame fusions without progression to acute leukemia

Chromosomal rearrangements of the MLL gene are uncommon in myelodysplastic syndromes (MDSs), and few studies of their molecular structures and oncogenic mechanisms exist. Here, we present a case of de novo MDS with a normal karyotype at initial diagnosis and a mild clinical course. Five years after the initial diagnosis, investigators identified a complex rearrangement of the MLL gene without progression to acute leukemia. The 5' part of the MLL gene is fused out of frame with the LOC100131626 gene, and the 3' part of the MLL gene out of frame with the TCF12 gene. Rapid amplification of complementary DNA 3' ends yielded two main fusion transcripts, which is in concordance with the two described isoforms of the LOC100131626 gene. For both isoform-fusion transcripts, the open reading frame terminates shortly after the breakpoint that is predicted to form two de facto truncated MLL proteins and disrupts the open reading frame of the LOC100131626, TCF12, and UBE4A genes. Neither dimerization nor a transcriptional activation domain, each of which is causally linked to MLL protein-mediated transformation, is present. This and other unusual MLL rearrangements probably represent a subclass of MLL gene abnormalities that have intrinsically no ability or only a weak ability to transform hematopoeitic cells and are identified only in the context of other hematopoetic malignancies.

MLL-SEPTIN gene fusions in hematological malignancies

The mixed lineage leukemia (MLL) locus is involved in more than 60 different rearrangements with a remarkably diverse group of fusion partners in approximately 10% of human leukemias. MLL rearrangements include chromosomal translocations, gene internal duplications, chromosome 11q deletions or inversions and MLL gene insertions into other chromosomes, or vice versa. MLL fusion partners can be classified into four distinct categories: nuclear proteins, cytoplasmatic proteins, histone acetyltransferases and septins. Five different septin genes (SEPT2, SEPT5, SEPT6, SEPT9, and SEPT11) have been identified as MLL fusion partners, giving rise to chimeric fusion proteins in which the N terminus of MLL is fused, in frame, to almost the entire open reading frame of the septin partner gene. The rearranged alleles result from heterogeneous breaks in distinct introns of both MLL and its septin fusion partner, originating distinct gene fusion variants. MLL-SEPTIN rearrangements have been repeatedly identified in de novo and therapy related myeloid neoplasia in both children and adults, and some clinicopathogenetic associations are being uncovered. The fundamental roles of septins in cytokinesis, membrane remodeling and compartmentalization can provide some clues on how abnormalities in the septin cytoskeleton and MLL deregulation could be involved in the pathogenesis of hematological malignancies.

Clinical and genetic features of therapy-related myeloid neoplasms after chemotherapy for acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a highly curable disease with excellent complete remission and long-term survival rates. However, the development of therapy-related myeloid neoplasms (t-MN) is being reported with increasing frequency in patients successfully treated for APL. We attempted to clarify the different clinical features and hematologic findings between t-MN and relapse cases, and to identify gene alterations involved in t-MN. We compared 10 relapse and 11 t-MN cases that developed in 108 patients during their first complete remission from APL. At APL diagnosis, t-MN patients had lower white blood cell counts than did relapse patients (P = .048). Overall survival starting from chemotherapy was significantly worse in t-MN patients than in relapse patients (P = .022). The t-MN cases were characterized as CD34(+)/HLA-DR(+) and PML-RARA(-), and 4 RUNX1/AML1 mutations were detected. T-MN is easily distinguished from APL relapse by evaluating these hematologic features, and it may originate from primitive myeloid cells by chemotherapy-induced RUNX1 mutations.

Secondary clonal cytogenetic abnormalities following successful treatment of acute promyelocytic leukemia

To identify patients who developed secondary clonal cytogenetic aberrations (CCA) following therapy for acute promyelocytic leukemia (APL), we retrospectively analyzed cytogenetic results from 123 patients diagnosed with APL between 1995 and 2007, who had ongoing cytogenetic analysis undertaken in our laboratory. During follow-up for APL we identified 12 patients (9.8%) who developed CCA, not detected at diagnosis of APL and unrelated to their original APL karyotype. All patients had received all-trans retinoic acid (ATRA) and chemotherapy and were in complete remission for APL when secondary CCA were identified. The median latency period between diagnosis of APL and emergence of secondary CCA was 27.5 months (range: 2-54 months). To date, four patients with CCA have been diagnosed with therapy-related myelodysplastic syndrome (t-MDS)/acute myeloid leukemia (t-AML), giving a median t-MDS/AML free survival of 78 months, with follow-up ranging between 20 and 136 months from APL diagnosis. Three patients have died: two patients died of t-AML and another developed relapsed APL with persistence of his secondary clone but no diagnosis of t-MDS/AML and died from transplant-related complications. Two patients are alive with t-MDS. Seven patients with CCA are alive with no morphological evidence of MDS at the time of their last known follow-up; thus median survival has not been reached. The appearance of these abnormalities in the absence of morphological evidence of MDS in the majority of patients is unusual, and highlights the importance of continued cytogenetic follow-up in these patients. Am. J. Hematol., 2009. (c) 2009 Wiley-Liss, Inc.

Both SEPT2 and MLL are down-regulated in MLL-SEPT2 therapy-related myeloid neoplasia

Background

A relevant role of septins in leukemogenesis has been uncovered by their involvement as fusion partners in MLL-related leukemia. Recently, we have established the MLL-SEPT2 gene fusion as the molecular abnormality subjacent to the translocation t(2;11)(q37;q23) in therapy-related acute myeloid leukemia. In this work we quantified MLL and SEPT2 gene expression in 58 acute myeloid leukemia patients selected to represent the major AML genetic subgroups, as well as in all three cases of MLL-SEPT2-associated myeloid neoplasms so far described in the literature.

Methods

Cytogenetics, fluorescence in situ hybridization (FISH) and molecular studies (RT-PCR, qRT-PCR and qMSP) were used to characterize 58 acute myeloid leukemia patients (AML) at diagnosis selected to represent the major AML genetic subgroups: CBFB-MYH11 (n = 13), PML-RARA (n = 12); RUNX1-RUNX1T1 (n = 12), normal karyotype (n = 11), and MLL gene fusions other than MLL-SEPT2 (n = 10). We also studied all three MLL-SEPT2 myeloid neoplasia cases reported in the literature, namely two AML patients and a t-MDS patient.

Results

When compared with normal controls, we found a 12.8-fold reduction of wild-type SEPT2 and MLL-SEPT2 combined expression in cases with the MLL-SEPT2 gene fusion (p = 0.007), which is accompanied by a 12.4-fold down-regulation of wild-type MLL and MLL-SEPT2 combined expression (p = 0.028). The down-regulation of SEPT2 in MLL-SEPT2 myeloid neoplasias was statistically significant when compared with all other leukemia genetic subgroups (including those with other MLL gene fusions). In addition, MLL expression was also down-regulated in the group of MLL fusions other than MLL-SEPT2, when compared with the normal control group (p = 0.023)

Conclusion

We found a significant down-regulation of both SEPT2 and MLL in MLL-SEPT2 myeloid neoplasias. In addition, we also found that MLL is under-expressed in AML patients with MLL fusions other than MLL-SEPT2.