[Chromosome 17 abnormalities in patients with primary myelodysplastic syndrome: incidence and biologic significance]

The prognostic significance of chromosome 17 abnormalities in patients with myelodysplastic syndrome treated with 5-azacytidine: Results from the Hellenic 5-azacytidine registry

In patients with myelodysplastic syndrome (MDS), the prognostic significance of chromosome 17 abnormalities has not yet been fully elucidated, except for isochromosome 17q that has been characterized as an intermediate risk abnormality in the Revised International Prognostic Scoring System (IPSS‐R). To further characterize the prognostic significance of chromosome 17 abnormalities we analyzed the hematologic and prognostic characteristics of 548 adult patients with MDS treated with 5‐azacytidine through the Hellenic 5‐azacytidine registry and found 32 patients with a chromosome 17 abnormality (6 with i[17q], 15 with ‐17, 3 with add[17p] and the rest with other rarer abnormalities, mostly translocations). The presence of a chromosome 17 abnormality was correlated with poor prognostic features (high IPSS, IPSS‐R, and WPSS scores) and a low overall survival rate (15.7 vs 36.4 months for patients without chromosome 17 abnormalities, Kaplan–Meier, Log Rank P < 0.00001), but these results were confounded by the fact that most (92.3%) of the cases with a chromosome 17 abnormality (with the exception of i(17q) that was found in all cases as an isolated abnormality) were found in the context of a complex karyotype. Nevertheless, one should not ignore the contribution of chromosome 17 abnormalities to the prognostic significance of a complex karyotype since 33.8% of complex karyotypes encompassed a chromosome 17 abnormality.

SETBP1 dysregulation in congenital disorders and myeloid neoplasms

Myeloid malignancies are characterized by an extreme molecular heterogeneity, and many efforts have been made in the past decades to clarify the mechanisms underlying their pathogenesis.

In this scenario SET binding protein 1 (SETBP1) has attracted a lot of interest as a new oncogene and potential marker, in addition to its involvement in the Schinzel-Giedon syndrome (SGS). Our review starts with the analysis of the structural characteristics of SETBP1, and extends to its corresponding physiological and pathological functions. Next, we describe the prevalence of SETBP1 mutations in congenital diseases and in hematologic malignancies, exploring how its alterations might contribute to tumor development and provoke clinical effects. Finally, we consider to understand how SETBP1 activation could be exploited in molecular medicine to enhance the cure rate.

Mutations in SETBP1 are recurrent in myelodysplastic syndromes and often coexist with cytogenetic markers associated with disease progression

Whole exome sequencing was performed in a patient with myelodysplastic syndrome before and after progression to acute myeloid leukaemia. Mutations in several genes, including SETBP1, were identified following leukaemic transformation. Screening of 328 patients with myeloid disorders revealed SETBP1 mutations in 14 patients (4·3%), 7 of whom had -7/del(7q) and 3 had i(17)(q10), cytogenetic markers associated with shortened overall survival and increased risk of leukaemic evolution. SETBP1 mutations were frequently acquired at the time of leukaemic evolution, coinciding with increase of leukaemic blasts. These data suggest that SETBP1 mutations may play a role in MDS and chronic myelomonocytic leukaemia disease progression.

Case report of isochromosome 17q in acute myeloid leukemia with myelodysplasia-related changes after treatment with a hypomethylating agent

Isochromosome 17q is a relatively common karyotypic abnormality in medulloblastoma, gastric, bladder, and breast cancers. In myeloid disorders, it is observed during disease progression and evolution to acute myeloid leukemia in Philadelphia-positive chronic myeloid leukemia. It has been reported in rare cases of myelodysplastic syndrome, with an incidence of 0.4-1.57%. Two new agents have been approved for treatment of myelodysplastic syndrome/chronic myelomonocytic leukemia. These are the hypomethylating agents, 5-azacytidine and decitabine, recommended by consensus guidelines for high-risk myelodysplastic syndrome patients not eligible for hematopoietic stem cell transplantation. We present a case of chronic myelomonocytic leukemia with normal cytogenetics at diagnosis treated with decitabine (with good response); however, the patient evolved to acute myeloid leukemia with i(17q) shortly after suspending treatment. To the best of our knowledge, this is the first report of acute myeloid leukemia with myelodysplasia-related changes with i(17q) after the use of a hypomethylating agent.

Two distinct clonal populations in acute promyelocytic leukemia, one involving chromosome 17 and the other involving an isochromosome 17

Acute promyelocytic leukemia (APL) is characterized by a t(15;17)(q22;q21) rearrangement. Additional chromosomal rearrangements have been reported in 25-40% of APL patients. The most common abnormality involving chromosome 17 is ider(17). Here we report the case of a patient with APL with isochromosome 17q combined with ider(17), confirmed by fluorescence in situ hybridization. Cytogenetic data strongly suggest that the involvement of chromosomes 15 and 17 in translocation occurs after formation of the isochromosome 17. The case reported here presents the novel finding of two separate clonal events apparently occurring at the same time in an APL patient.