Peculiarities of abnormal karyotypes formation in therapy-related acute leukemias.

AIM: To determine ways of formation of abnormal karyotypes in two clinical cases of secondary acute leukemias of myeloid and lymphoid lineages. MATERIAL AND METHODS: Bone marrow cells of one patient with therapy-related acute monoblastic/monocytic leukemia and one patient with therapy-related acute lymphoblastic leukemia were examined by cytogenetic GTG banding technique. RESULTS: An unusually large number of quantitative and structural anomalies of chromosomes in therapy-related acute monoblastic/monocytic leukemia have been established, which have many features in common with chromothripsis, namely instability of clones that manifested itself through quantitative anomalies (trisomy, monosomy, marker chromosomes, including chromosome 5), structural - t(9;11), deletions of the long arm of chromosomes 8 and 14, derivatives of chromosomes 3 and 7, ring chromosomes. In case of secondary acute lymphoblastic leukemia, the anomalous clone with balanced translocation in all 20 metaphase plates 46,XX,t(1;15)(p21;q24) has been registered, which is not described in the literature. Therefore, the diagnostic and prognostic value of such anomaly is unknown. CONCLUSIONS: Rearrangement with the involvement of the locus 11q23 was recorded in the case of chemotherapy treatment without topoisomerase II inhibitors. The complex karyotype formed after chemotherapy and radiotherapy, which is a criterion for an unfavorable prognosis of the disease, is considered as the equivalent of chromothripsis. t(1;15) is considered as an abnormality that can be attributed to the group of favorable secondary acute lymphoblastic leukemia prognosis.

Treatment-related acute granulocyte-monocytic leukemia from multiple myeloma: A case report and literature review.

RATIONALE: To investigate the clinical features of treatment-related acute granulocyte-monocytic leukemia (t-AML) from multiple myeloma (MM) thereby improving the understanding of this disease. PATIENT CONCERNS: A 72-year-old woman patient was initially diagnosed as MM. Two years and 7 months after treatment, this patient developed AML M4 as confirmed by the analyses from clinical features, bone marrow morphology, flow cytometry, and cytogenetic examination. DIAGNOSIS: Treatment-related acute myeloid leukaemia (t-AML). INTERVENTIONS: Due to lack of the ability to pay the cost, she declined our recommendation to accept therapy as an inpatient and was discharged. LESSONS: The reported case was a rare t-AML, which is resistant to currently available treatments and has a poor prognosis.

[A case of therapy-related acute monocytic leukemia following low-dose of etoposide treatment for hemophagocytic lymphohistiocytosis].

We report a case of therapy-related acute myeloid leukemia after low-dosed topoisomerase II inhibitor (etoposide) treatment for hemophagocytic lymphohistiocytosis (HLH). A 62-yr-old female patient had previously been treated with a HLH-94 protocol containing a low-dose of etoposide (total dose of 300 mg/m2). Thirty-one months later, the patient was admitted to the hematology department with general weakness and upper respiratory infection symptoms. Peripheral blood smear and bone marrow study revealed acute monocytic leukemia. There was no evidence of myelodysplastic syndrome, and a cytogenetic study showed no chromosomal abnormalities.

A Case of Therapy-Related Acute Monocytic Leukemia following Low-dose of Etoposide Treatment for Hemophagocytic Lymphohistiocytosis / 대한진단검사의학회지

We report a case of therapy-related acute myeloid leukemia after low-dosed topoisomerase II inhibitor (etoposide) treatment for hemophagocytic lymphohistiocytosis (HLH). A 62-yr-old female patient had previously been treated with a HLH-94 protocol containing a low-dose of etoposide (total dose of 300 mg/m2). Thirty-one months later, the patient was admitted to the hematology department with general weakness and upper respiratory infection symptoms. Peripheral blood smear and bone marrow study revealed acute monocytic leukemia. There was no evidence of myelodysplastic syndrome, and a cytogenetic study showed no chromosomal abnormalities.

Acute promyelocytic leukemia with PML-RARA fusion on i(17q) and therapy-related acute myeloid leukemia.

We describe a patient with acute promyelocytic leukemia (APL) and the karyotype 46,XX,i(17)(q10) with PML-RARA fusion gene detected by fluorescence in situ hybridization (FISH) and nested reverse transcriptase-polymerase chain reaction (RT-PCR). FISH using dual-color translocation probes for PML (promyelocytic leukemia) and RARA (retinoic acid receptor-alpha) showed fusion signal for PML-RARA on both arms of i(17q). The patient attained complete remission (CR) with all-trans retinoic acid treatment and became PML-RARA negative. One year later, while PML-RARA negative on FISH and RT-PCR, the patient presented with thrombocytopenia. Bone marrow examination suggested an acute monoblastic leukemia (AML-M5a) including the karyotype 46,XX,t(8;16) (p11.2;p13.3),inv(11)(p15q22 approximately q23)[11]/47,idem,+i(8)(q10)[9]. She is currently in CR. The occurrence of therapy related acute leukemia after successful therapy for APL is an emerging problem.

Secondary acute monocytic leukemia with a translocation t(8;16)(p11;p13): case report and review of the literature.

Acute myeloblastic leukemia cases carrying the translocation t(8;16) (p11;p13) are characterized by the M4 and M5 subtypes, erythrophagocytosis by the blast cells and a poor prognosis, suggesting a new clinical entity. The t(8;16) fuses the MOZ gene which encodes a histone acetyltransferase, located on 8p11 with the CBP gene which also encodes a histone acetyltransferase, located on 16p13, and recent reports suggested that the chimeric transcription MOZ-CBP is essential for leukemogenesis. A 68-year-old woman who had been treated mainly with paclitaxel and carboplatin for preceding ovarian cancer was admitted to our hospital, complaining of right breast mass. She was diagnosed as having breast cancer and acute monocytic leukemia (M5b). Cytogenetic study with spectral karyotyping analysis revealed the development of 47 XX, + 8, t(8;16)(p11;p13). Eleven cases of therapy-related t(8;16) leukemia including the present case have been reported, but prior treatment with paclitaxel and carboplatin-based chemotherapy has never been reported. The relation of histone acetylase and therapy-related leukemia is discussed.

Erythropoietin-dependent transformation of myelodysplastic syndrome to acute monoblastic leukemia.

Acute monoblastic leukemia (acute myeloid leukemia [AML], French-American-British type M5a) with leukemia cutis developed in a patient 6 weeks after the initiation of erythropoietin (EPO) therapy for refractory anemia with ringed sideroblasts. AML disappeared from both marrow and skin after the discontinuation of EPO. Multiparameter flow cytometric analysis of bone marrow cells demonstrated coexpression of the EPO receptor with CD45 and CD13 on the surface of blasts. The incubation of marrow cells with EPO, compared to without, resulted in 1.3- and 1.6-fold increases, respectively, in tritiated thymidine incorporation and bromodeoxyuridine incorporation into CD13(+) cells. Clinical and laboratory findings were consistent with the EPO-dependent transformation of myelodysplastic syndrome (MDS) to AML. It is concluded that leukemic transformation in patients with MDS treated with EPO may be EPO-dependent and that management should consist of the discontinuation of EPO followed by observation, if clinically feasible.

Human LPP gene is fused to MLL in a secondary acute leukemia with a t(3;11) (q28;q23).

The mixed lineage leukemia, MLL, gene is frequently rearranged in patients with secondary leukemia following treatment with DNA topoisomerase II inhibitors. By FISH and Southern blot analyses we identified a rearrangement in the MLL gene due to a novel t(3;11)(q28;q23) chromosomal translocation in a patient who developed AML-M5 3 years after treatment for a follicular lymphoma. Through inverse PCR, the LPP (lipoma preferred partner) gene on 3q28 was identified as the MLL fusion partner. LPP contains substantial identity to the focal adhesion protein, zyxin, and is frequently fused to HMGIC in lipomas. The breakpoint occurred in intron 8 of MLL and LPP. Two in-frame MLL-LPP transcripts, which fuse MLL exon 8 to LPP exon 9, were detected by RT-PCR, although the smaller of these contained a deletion of 120 bp from the MLL sequence. The predicted MLL-LPP fusion protein includes the A/T hook motifs and methyltransferase domain of MLL joined to the two last LIM domains of LPP. A reciprocal LPP-MLL transcript, predicted to include the proline-rich and leucine zipper motifs, and the first LIM domain of LPP were also detected by RT-PCR. In summary, LPP is a newly identified MLL fusion partner in secondary leukemia resulting from topoisomerase inhibitors. The MLL-LPP and LPP-MLL predicted proteins contain many of the features present in other MLL rearrangements.

Genomic organization, tissue expression, and cellular localization of AF3p21, a fusion partner of MLL in therapy-related leukemia.

We previously identified the AF3p21 gene, a novel fusion partner of the MLL gene, in a patient who had developed therapy-related leukemia with t(3;11)(p21;q23). The AF3p21 gene encodes a protein consisting of 722 amino acids, which has an SH3 (Src homology 3) domain, a proline-rich domain, and a bipartite nuclear localization signal. The protein's SH3 domain has high homology with that of FYN. Analysis of the DNA from the patient's leukemic cells revealed that intron 6 of the MLL gene was fused at a point upstream of exon 1 in the AF3p21 gene, and that the der(11) chromosome formed an MLL-AF3p21 fusion transcript in leukemic cells, whereas the der(3) chromosome did not form any fusion transcript. The AF3p21 gene on chromosome band 3p21 is 19 kb long and consists of 13 exons. The size of the mRNA of the AF3p21 gene is approximately 3.5 kb. The AF3p21 gene is widely expressed in normal human tissues including the bone marrow, brain, liver, thymus, lung, and skeletal muscle. Western blot and immunocytochemical analyses showed that AF3p21 protein has an apparent molecular weight of 80 kDa and is localized exclusively in the cell nucleus. These results suggest the possibility that AF3p21 protein plays a role in signal transduction in the nucleus.

Novel SH3 protein encoded by the AF3p21 gene is fused to the mixed lineage leukemia protein in a therapy-related leukemia with t(3;11) (p21;q23).

The mixed lineage leukemia (MLL) gene located at chromosome band 11q23 is frequently rearranged in patients with therapy-related acute monocytic leukemia who received topoisomerase II inhibitors. We have identified a novel fusion partner of MLL (FAB M5b) in a patient who developed t-AML 9 years after treatment for acute lymphoblastic leukemia (ALL). The leukemic cells had a sole karyotypic abnormality of t(3;11) (p21;q23). Screening of a genomic DNA library, prepared from leukemic cell DNA, identified rearranged clones composed of MLL and a novel gene on chromosome 3p21 (AF3p21). The AF3p21 gene encodes a protein of 722 amino acids, which contains an Src homology 3 (SH3) domain, a proline-rich domain, and a bipartite nuclear localizing signal (NLS). RNA analysis demonstrated that exon 6 of the MLL gene fused to exon 2 of the AF3p21 gene. The resulting chimeric protein consists of AT-hooks, methyltransferase, and transcription repressor domains of MLL in addition to the AF3p21 proline-rich domain and NLS but not the AF3p21 SH3 domain.

Secondary acute myeloid leukemia following treatment with VP16-containing regimens for non-Hodgkin's lymphoma.

We report on two patients who developed a secondary acute myeloid leukemia (sAL) after treatment for non-Hodgkin's lymphoma (NHL) with regimens containing low to intermediate doses of VP16. Clinical and hematologic features in these two patients were consistent with epipodophyllotoxin-associated sAL. In one case, a rearrangement of chromosome band 11q23 was detected.

Secondary leukemia following high cumulative doses of etoposide in patients treated for advanced germ cell tumors.

PURPOSE: High cumulative epipodophyllotoxin dosages are reported to be associated with an elevated risk for secondary acute myeloid leukemia (s-AML). This study examined the risk of s-AML following cumulative etoposide doses greater than 2 g/m2 in patients with metastatic germ cell tumors (GCT). PATIENTS AND METHODS: The incidence of s-AML was retrospectively assessed in patients treated within clinical trials between January 1986 and February 1996 at four university centers. All patients received high-dose chemotherapy (HDCT) plus autologous stem-cell support for metastatic GCT, including high cumulative etoposide doses (> 2 g/m2). Minimum patient follow-up was 12 months. Standardized morbidity ratio (SMR) was calculated to estimate the risk associated with high cumulative etoposide doses, as compared with the general population. RESULTS: A total of 302 patients with a median age of 29 years (range, 15 to 55) received a median cumulative etoposide dose of 5 g/m2 (range, 2.4 to 14 g/m2). Four cases of s-AML were observed, which resulted in a cumulative incidence of 1.3% (95% confidence interval [CI], 0.38% to 3.59%) at 52 months of median follow-up (range, 12 to 198). Two cases of secondary myelodysplasia (s-MDS) developed in patients with primary mediastinal GCT. Based on the observed four cases of AML, which are most likely etoposide-related, the risk for developing s-AML (SMR, 160 [95% CI, 43.7 to 411.2]) is significantly increased in comparison to the age-matched general population. CONCLUSION: Due to the low incidence of AML in the general population, the significantly elevated risk for developing s-AML affects only 1.3% of all patients who receive etoposide doses greater than 2 g/m2. HDCT, including etoposide doses greater than 2 g/m2, is associated with an acceptably low incidence of s-AML in patients with advanced GCT.