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Deletion 20q is a recurrent abnormality in myeloid malignancies. In our previous study, we identified fusion of the additional sex combs-like 1 (ASXL1) and teashirt zinc finger homeobox 2 genes in a patient with myelodysplastic syndrome. The objective of this study was to determine the frequency of ASXL1 breakpoints in a cohort of 36 patients with deletion 20q as the sole cytogenetic aberration. A combination of molecular cytogenetic methods was used to confirm ASXL1 gene alterations in 19 of the 36 patients, and the determination of ASXL1 gene changes in patients with deletion 20q revealed clinical and prognostic impacts.

Acute myeloid leukemia (AML) is a severe condition with a high mortality. When making decisions about the optimal tailor-made therapy, numerous prognostic factors are considered. The study represents a detailed analysis of the role of these factors and treatment outcomes based on a long-term follow-up of patients treated in 5 hematology intensive care centers in the Czech Republic.The studied group comprised 1,188 patients with de novo AML and 328 patients with secondary AML. The latter were significantly older, had more unfavorable cytogenetic changes and less frequently received curative therapy. Curatively treated patients achieved fewer complete remissions and relapsed more often than those with de novo AML. Patients with secondary AML had lower rates of allogeneic transplantation as part of consolidation therapy and a significantly shorter median overall survival. A lower proportion of the patients were alive at the time of analysis. However, the treatment outcome of de novo AML patients is not satisfactory, the only exception being those with acute promyelocytic leukemia. The analysis, which did not evaluate the intention-to-treat criteria and was without randomization, found allogeneic stem cell transplantation to be the most effective modality of consolidation therapy in both groups of patients. .

Unlabelled: Telomere length was evaluated by terminal repeat fragment method in 66 previously untreated patients with B-chronic lymphocytic leukemia (B-CLL) to ascertain whether telomere shortening was associated with genomic aberrations, immunoglobulin variable heavy chain (IgVH) mutational status, CD38 and ZAP-70 expression, and telomerase activity. Chromosomal aberrations were present in peripheral blood cells of 73% patients (48/66), no difference in telomere length between patients with good and intermediate prognosis according to cytogenetics was found. Association between telomere length and IgVH mutational status, ZAP-70 and CD38 expression was proved as significantly shorter telomeres in patients with unmutated IgVH status (p=0.01) and ZAP-70 positivity (p=0.01) and CD38 positivity (p=0.05) were detected. Telomerase activity was positive in 11 patients out of 21 examined, correlation between telomere length and telomerase activity was found (p=0.05). Telomere length and telomerase activity in combination with other prognostic parameters complete the risk profile of B-CLL patients and might serve for an easy decision on optimal treatment strategy., Keywords: B-chronic lymphocytic leukemia, telomere length, telomerase activity, chromosomal aberrations, prognosis.

Dasatinib is effective second line treatment for patients with chronic myeloid leukemia (CML) resistant or intolerant to imatinib. We report here the first experiences with dasatinib therapy in 71 CML patients resistant or intolerant to imatinib from the real clinical practice of 6 hematological centers in the Czech Republic. Dose 100 mg daily and 70 mg twice daily was administered to patients with chronic phase (CP) and advanced phases (AP) CML. In chronic phase (n=46), complete hematological reponse (CHR) was achieved in 97%, major cytogenetic reponse (MCgR) in 77% and complete cytogenetic response (CCgR) in 67%. Major molecular reponse (MMR) was achieved in 19/31 patients in median of 10 months. In advanced phase (n=25), CHR was attained in 77%, MCgR in 39%, CCgR in 33% and MMR in 2/18 patients. Eleven different baseline mutations were followed up in 15 patients. Dasatinib eliminated mutations in most of the patients, but 3 patients acquired a new one. Novel mutations were detected under dasatinib therapy in 2 patients. Dasatinib was well tolerated, cytopenias were common and was managed by dose modification. The estimated progression free survival (PFS) at 12 months was 97+/-3% in CP and 62+/-21% in AP. The median time to treatment failure was 605 days in AP while it was not reached in CP patients. Our clinical experiences, described here, confirmed that dasatinib is associated with high response rates especially in imatinib resistant or intolerant CML patients in chronic phase.

The results of repeated interphase fluorescence in-situ hybridization (I-FISH, FISH) examination of 97 CLL patients and correlation of these findings with IgVH hypermutation status, ZAP-70 and CD38 expression are presented. The appearance of new, FISH-detectable, genomic aberrations during disease course, described as clonal evolution (CE), was observed in 26% of patients. The most frequent newly acquired cytogenetic abnormality was 13q deletion in 64% (16/25). In contrast to earlier studies, there was no correlation found between CE and either one of single negative prognostic factors (unmutated IgVH; CD38 positivity; ZAP-70 positivity). However, the combination of all three negative factors correlated with CE highly significantly (p=0.005) and moreover, also with a shift from lower to higher FISH risk category (p=0.010). As the prognostic data were known in all patients, this study represents the complete insight on the association of CE and other risk parameters in CLL.

Chronic myeloid leukemia (CML) is a myeloproliferative disorder caused by clonal proliferation of primitive hematopoietic stem cell. The median age at diagnosis is 55 to 60 years with less than 10% of patients younger 20 years. Incidence of CML in children in the Czech Republic is 0.106 cases/100 thousands per year. Here we report outcome of 38 pediatric patients (median age 12.5 years; range 1.8 - 17.3) with Ph-positive CML diagnosed between years 1989 to 2006. Primarily chronic phase of the disease was diagnosed in 32 (84%) patients. 32 (84.2%) patients underwent hematopoietic stem cell transplantation (HSCT) with the median age at transplantation of 14.9 years (range 6.9 - 20.5 years). Out of transplanted patients 16 (50%) obtained graft from unrelated donor, 13 (41%) from matched sibling donor, 2 from haploidentical family donor and autologous transplantation has been performed in one case. 6 patients were not transplanted, 4 of them died (median 1.2 years from diagnosis), 2 are alive 0.6 and 17.8 years from the diagnosis. Overall survival (OS) in 25 patients after HSCT at our department during the whole period is 66.7% with 15/16 being in stable continuous molecular-genetic remission (94%). During the period of time results of transplantations have been significantly improved (p=0.0071). OS after HSCT until year 1997 is 25% while from year 1998 until now is 87.5%. All centers OS of patients after HSCT is 71%. Results of HSCT in children with CML obtained from the year 1998 at our center are fully comparable with results achieved in large and experienced centers. HSCT remains the only proven and effective method for the treatment of CML. Clinical studies assessing the role of tyrosine kinase inhibitors in children instead of early HSCT should be planned carefully in order to avoid sub-optimal outcomes.

Interphase fluorescence in situ hybridization was used to detect common deletions in B-CLL patients as well as trisomy 12 and aberrations of IgH gene complex at 14q32.33 where we evaluated not only translocation-like signal pattern but also deletions. 120 (82%) patients showed genetic changes - del(13)(q14) 95 (62%), deletion of ATM gene 22 (15%), deletion of p53 gene 25 (17%) and trisomy 12 was proved in 18 (12%) cases. IgH rearrangements were detected in 45 (31%), split of the signals in 11 (8%), deletion of 3' segment flanking IgH gene in 5 (3%) and deletions of variable segment in 29 (20%) patients. Although deletions of 3' segment flanking IgH gene complex are supposed to have an adverse prognostic impact and the genetic background of variable segment deletions is believed to be most probably physiological, we assumed a detailed mapping of the 14q32.33 region will be needed to unravel these mysteries.

Bladder cancer is a heterogenous malignancy with wide scale of clinical manifestation. Different chromosomal aberrations have been already identified in bladder tumors. These aberrations can be detected by multicolor interphase fluorescence in situ hybridization (I-FISH) or comparative genomic hybridization (CGH). The aim of this study was to determine the diagnostic benefits of non-invasive I-FISH method and to comprehensively characterise genetic alterations using CGH in selected patients with bladder tumors. We examined 128 urine samples and correlated our results with histological findings. I-FISH using UroVysion kit showed positivity in 63,6 % of G1 tumors, 64,3 % of G2 tumors and 91,7 % in G3 tumors. We examined also 12 bladder tissue samples by means of CGH and various genetic alterations were ascertained independent on tumor grade. The most frequent gains and losses of DNA material were detected on chromosomes 1, 8, 9, 10, 11, 13, and 14. The contribution of I-FISH is in an early and non-invasive detection of bladder cancer recurrences during follow up of patients after the surgery. CGH provides information about further genetic alterations and some of them could be ascertained as recurrent changes with prognostic significance.

Monitoring of BCR-ABL transcript level is widely used in chronic myeloid leukemia (CML) to follow up response to therapy. In this study we compare abilities of two quantitative RT-PCR assays to characterize the disease status in CML patients: RT-PCR quantifying the BCR-ABL transcript concentration and RT-PCR determining the BCR-ABL/BCR transcript ratio (R). We demonstrate that in non-responders only R, but not BCR-ABL, unambiguously characterizes the state of disease. Moreover, R values >1 found in all poor responders indicate lower BCR expression compared to BCR- ABL in these patients. Our results demonstrate the importance of BCR-ABL/BCR transcript ratio for the disease status and the disease prognosis characterization and suggest a possible role of the normal BCR gene expression in CML pathogenesis.