Determinants of lenalidomide response with or without erythropoiesis-stimulating agents in myelodysplastic syndromes: the HOVON89 trial.

A randomized phase-II study was performed in low/int-1 risk MDS (IPSS) to study efficacy and safety of lenalidomide without (arm A) or with (arm B) ESA/G-CSF. In arm B, patients without erythroid response (HI-E) after 4 cycles received ESA; G-CSF was added if no HI-E was obtained by cycle 9. HI-E served as primary endpoint. Flow cytometry and next-generation sequencing were performed to identify predictors of response. The final evaluation comprised 184 patients; 84% non-del(5q), 16% isolated del(5q); median follow-up: 70.7 months. In arm A and B, 39 and 41% of patients achieved HI-E; median time-to-HI-E: 3.2 months for both arms, median duration of-HI-E: 9.8 months. HI-E was significantly lower in non-del(5q) vs. del(5q): 32% vs. 80%. The same accounted for transfusion independency-at-week 24 (16% vs. 67%), but similar in both arms. Apart from presence of del(5q), high percentages of bone marrow lymphocytes and progenitor B-cells, a low number of mutations, absence of ring sideroblasts, and SF3B1 mutations predicted HI-E. In conclusion, lenalidomide induced HI-E in patients with non-del(5q) and del(5q) MDS without additional effect of ESA/G-CSF. The identified predictors of response may guide application of lenalidomide in lower-risk MDS in the era of precision medicine. (EudraCT 2008-002195-10).

Bortezomib before and after high-dose therapy in myeloma: long-term results from the phase III HOVON-65/GMMG-HD4 trial.

The Dutch-Belgian Cooperative Trial Group for Hematology Oncology Group-65/German-speaking Myeloma Multicenter Group-HD4 (HOVON-65/GMMG-HD4) phase III trial compared bortezomib (BTZ) before and after high-dose melphalan and autologous stem cell transplantation (HDM, PAD arm) compared with classical cytotoxic agents prior and thalidomide after HDM (VAD arm) in multiple myeloma (MM) patients aged 18-65 years. Here, the long-term follow-up and data on second primary malignancies (SPM) are presented. After a median follow-up of 96 months, progression-free survival (censored at allogeneic transplantation, PFS) remained significantly prolonged in the PAD versus VAD arm (hazard ratio (HR)=0.76, 95% confidence interval (95% CI) of 0.65-0.89, P=0.001). Overall survival (OS) was similar in the PAD versus VAD arm (HR=0.89, 95% CI: 0.74-1.08, P=0.24). The incidence of SPM were similar between the two arms (7% each, P=0.73). The negative prognostic effects of the cytogenetic aberration deletion 17p13 (clone size ⩾10%) and renal impairment at baseline (serum creatinine >2 mg dl-1) on PFS and OS remained abrogated in the PAD but not VAD arm. OS from first relapse/progression was similar between the study arms (HR=1.02, P=0.85). In conclusion, the survival benefit with BTZ induction/maintenance compared with classical cytotoxic agents and thalidomide maintenance is maintained without an increased risk of SPM.

Heterogeneous patterns of amplification of the NUP214-ABL1 fusion gene in T-cell acute lymphoblastic leukemia.

Episomes with the NUP214-ABL1 fusion gene have been observed in 6% of T-ALL. In this multicentric study we collected 27 cases of NUP214-ABL1-positive T-ALL. Median age was 15 years with male predominance. Outcome was poor in 12 patients. An associated abnormality involving TLX1 or TLX3 was found in all investigated cases. Fluorescent in situ hybridization revealed a heterogeneous pattern of NUP214-ABL1 amplification. Multiple episomes carrying the fusion were detected in 24 patients. Episomes were observed in a significant number of nuclei in 18 cases, but in only 1-5% of nuclei in 6. In addition, intrachromosomal amplification (small hsr) was identified either as the only change or in association with episomes in four cases and two T-ALL cell lines (PEER and ALL-SIL). One case showed insertion of apparently non-amplified NUP214-ABL1 sequences at 14q12. The amplified sequences were analyzed using array-based CGH.These findings confirm that the NUP214-ABL1 gene requires amplification for oncogenicity; it is part of a multistep process of leukemogenesis; and it can be a late event present only in subpopulations. Data also provide in vivo evidence for a model of episome formation, amplification and optional reintegration into the genome. Implications for the use of kinase inhibitors are discussed.

Hypotriploidy 68,XX: a new case report and review of earlier cases.

We report a prematurely born patient with a 68,XX karyotype. She presented with syndactyly of 2nd and 3rd toes, minor facial features, microcephaly, slender hands, bicuspid aortic valve, patent ductus arteriosus and hypotonia. Comparison with other reported cases is given.

Translocation t(2;3)(p15-23;q26-27) in myeloid malignancies: report of 21 new cases, clinical, cytogenetic and molecular genetic features.

Chromosomal rearrangements involving 3q26 either due to inversion or translocation with various partner chromosomes are a recurrent finding in malignant myeloid disorders. Typically, these chromosome aberrations contribute to ectopic expression of or to the formation of fusion genes involving the EVI1 proto-oncogene. Chromosomal translocations involving the short arm of chromosome 2 (p15-p23) and the distal part of the long arm of chromosome 3 (q26-q27) are a rare but recurrent finding in patients with myeloid malignancies, and are assumed to be part of this spectrum of disorders. Thus far, however, these translocations have been poorly studied. Here, we present 21 new cases with myelodysplasia, acute myeloid leukemia or CML in blast crisis, which upon karyotyping showed the presence of a t(2;3). Furthermore, an extensive literature review disclosed 29 additional cases. Morphological, clinical and cytogenetic assessment revealed the typical hallmarks of 3q26/EVI1 rearrangements, that is, trilineage dysplasia and dysmegakaryopoiesis, poor prognosis and additional monosomy 7. Molecular cytogenetic analysis and PCR in selected samples indicated that in most cases the translocation indeed targets the EVI1 locus. Mapping of the chromosome 2 breakpoints confirmed the initially suspected cytogenetic breakpoint heterogeneity at the 2p arm.

Complex chromosome 9, 20, and 22 rearrangements in acute lymphoblastic leukemia with duplication of BCR and ABL sequences.

Cytogenetic analysis was performed on bone marrow cells from a 28-year-old woman who was diagnosed with acute lymphoblastic leukemia (ALL). Her karyotype was: 46,XX,t(9;22)(q34;q11)[6]/47, XX,+8,t(9;22)(q34;q11)[4]/47,XX,+8,t(9;22)(q34;q11),del(20)(q11)[2]/46, XX,t(9;22)(q34;q11),del[20](q11)[7]/45,XX,der(9)t(9;22)(q34;q11),-20,-22 , +mar1[8]/45,XX,der(9)t(9;22)(q34;q11),-20,-22,+mar2[3]. Both marker chromosomes are dicentric and have the same size and banding pattern but different primary constrictions. Fluorescence in situ hybridization (FISH) demonstrated that both markers were derived from chromosomes 9, 20, and 22. FISH with the bcr/abl probe showed fusion of the BCR gene with the ABL gene; however, this fusion signal was present in duplicate on both marker chromosomes. To our knowledge, duplication of the BCR/ABL fusion signal on a single chromosome arm has not been reported before, except for the extensive amplification of BCR/ABL fusion signals in the leukemic cell line K-562. These data demonstrate that the marker chromosomes are the result of complex genomic rearrangements. At the molecular level, the BCR/ABL fusion gene encodes the p190 fusion protein. Similar findings have never been observed in any case of ALL.

Morphologically normal, CD30-negative B-lymphocytes with chromosome aberrations in classical Hodgkin's disease: the progenitor cell of the malignant clone?

A recent study observed that numerical chromosome abnormalities in Hodgkin's disease (HD) are detected not only in morphologically abnormal Hodgkin/Reed-Sternberg cells, but also in a fraction of morphologically normal cells. However, the phenotypic constitution of these genetically abnormal, morphologically normal cells and their relationship to the malignant Hodgkin/Reed-Sternberg cells could not be established in the earlier cases studied, because of the low frequency of these cells. The present study investigated two cases of classical Hodgkin's disease containing a relatively large population of such apparently normal cells with aberrant chromosome copy numbers. The phenotype and their position within the developmental route of the malignant compartment were examined by a combined in situ hybridization and immunocytochemistry approach. Numerical abnormalities for chromosome 1 in one case and for chromosomes X, Y, and 1 in the other case were observed not only in CD30-positive Hodgkin/Reed-Sternberg cells, but also in CD30-negative, morphologically normal cells. It was shown that these genetically aberrant cells expressed the B-cell antigen CD19, thus confirming their B-cell nature. These studies indicate a relationship between the genome aberrations in these genetically abnormal, morphologically normal B-cells and the Hodgkin/Reed-Sternberg cells, suggesting that they are progenitor cells of the malignant cell fraction.