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С 14 по 16 сентября 2006 г. в Санкт-Петербурге состоялась международная конференция «5 лет гливека в России», посвященная различным вопросам лечения хронического миелолейкоза (ХМЛ).

Therapy with tyrosine kinase inhibitors (TKI) allows to achieve a deep molecular response in 6070% of patients with chronic myeloid leukemia (CML). According to the current guidelines CML patients receive a long-term treatment with TKI in standard dose. The frequently observed adverse effects (AE) of TKI therapy are mostly dose-dependent. A new treatment approach with TKI use in reduced dose is desirable for the CML patients with existing AE or with a high risk of AE occurrence. We report the two cases of successful long-term treatment of CML patients with reduced doses of second generation TKIs. The aim of the TKI dose reduction was to reduce the clinical manifestations of drug toxicities and to prevent the AE.

Tyrosine kinase inhibitors have radically changed the course of chronic myeloid leukemia, significantly increasing survival and reducing the risk of disease progression. Nearly 50–70 % of patients achieve a consistently low or undetectable level of minimal residual disease – a deep molecular response. The long-term tyrosine kinase inhibitors treatment in about one-third of patients is accompanied by toxicity which impairs the quality of life. Therefore, the safe treatment discontinuation is relevant. The results of clinical trials have shown 40-60% possibility of maintaining treatment-free remission in patients with long-term deep molecular respons; however, all patients with molecular relapse regain molecular remission after the resumption of tyrosine kinase inhibitors therapy. Currently, clinical and biological factors associated with maintaining treatment-free remission are being studied. It is assumed that cessation of tyrosine kinase inhibitors therapy can improve the quality of life, but approximately 30 % of patients are reporting musculoskeletal pain – so called “withdrawal syndrome” – that begins or worsens after stopping tyrosine kinase inhibitors therapy. The mechanisms for the development of this phenomenon are currently unclear. Thus, many aspects concerning treatment-free remission require to be studied, which determines the importance of clinical trials in this area.

The additional molecular and chromosomal abnormalities (ACA) in Phositive cells usually considered as a genetic marker of chronic myeloid leukemia (CML) progression. 457 patients in different CML phases received tyrosine kinase inhibitors (1st and 2nd generation) were studied. During therapy 50 cases with additional chromosomal abnormalities in Ph+ clone (22 of them in chronic CML phase) were revealed (median follow-up from CML diagnosis – 117 months, median imatinib therapy – 62 months). 86 % of patients in chronic phase with Ph+- cell abnormalities were cytogenetic resistance, and their 5-years overall survival was 80 % which was significantly lower than in patients without ACA (p < 0.005). The treatment results depend on chromosomal abnormalities detected. In patients with additional chromosome 8 imatinib therapy is effective, although complete cytogenetic response (CCR) is achieved only in the later therapy stages. In patients with additional translocations CCR also achieved with imatinib or 2nd generation TKI. Only a third of patients with additional Ph-chromosome or BCR/ABL amplification achieved complete suppression of Ph+ clone using 2nd generation TKI. The presence of additional chromosome 7 abnormalities and complex karyotype disorders involving isochromosome i(17)(q10) are poor prognostic factors of TKI treatment failures.

Key words: chronic myeloid leukemia, BCR-ABL expression, automated GeneXpert method

Background. Withdrawal syndrome (WS) a musculoskeletal pain after discontinuation of tyrosine kinase inhibitors (TKI) in patients with chronic myeloid leukemia (CML) has been described in the treatment-free remission (TFR) studies. The pathophysiological mechanisms and predisposing factors of WS have not been well established. Aim. Our aim was to evaluate clinical features and factors associated with WS in the Russian cohort of CML patients who discontinued TKI therapy. Materials and methods. WS was evaluated in total of 183 CML patients with chronic phase and sustained deep molecular response (DMR). WS was defined as a musculoskeletal pain newly observed after TKI cessation or as a worsening of previously observed symptoms. Results. DMR loss free survival at 36 months was 49% and 43% in prospective and retrospective groups respectively (p=0.96) with mеdian (Me) time of observation 33 months (range 1136). WS was observed in 49 (27%) patients: grade 12 was in 45 (92%) patients, grade 3 in 4 (8%) patients. Me time to WS occurrence was 2 months (range 17), Ме duration of WS was 5 months (range 135). WS was resolved in 14 of 15 patients with molecular relapse after 13 months of TKI re-initiation and was decreased in 1 patient. WS was completely resolved in 31 of 34 patients who continued remained in TFR and decreased in 3 patients. WS was resolved spontaneously or with nonsteroidal anti-inflammatory drugs in 14 (45%) and 17 (55%) patients accordingly. Older age (p0.0001), longer duration of TKI therapy (p0.0001) and presence of locomotion system diseases (p=0.022) were observed in patients with WS. No WS was observed in pregnant patients (р0.001). Survival without DMR loss at 12 months after TKI stop was 66 and 42% in patients with and without WS accordingly (р=0.095). Conclusion. The rate of WS was 27% that is in a good concordance with the data of the other TFR studies. A longer period of TKI exposure, older age and the history of locomotion system diseases were associated with the development of the WS. We found for the first time that WS was not observed in patients with pregnancy. There was no association of WS development and the rate of molecular relapses.

Aim. To assess the results of following up patients with chronic myeloid leukemia (CML) and a deep molecular response (MR) without tyrosine kinase inhibitor (TKI) therapy. Subjects and methods. The reasons for TKI discontinuation in 70 patients with CML and a deep MR of more than 1 year’s duration were adverse events, pregnancy, and patients’ decision. Information was collected retrospectively and prospectively in 2008-2016. Results. The median follow-up after TKI therapy discontinuation was 23 months (2 to 100 months). At 6, 12 and 24 months after TKI therapy discontinuation, the cumulative incidence of major MR (MMR) loss was 28, 41 and 48%, respectively; the survival rates without TKI therapy were 69, 50, and 39%, respectively. MMR loss was noted in 28 (88%) patients at 12 months; it was not seen without TKI therapy at 2-year follow-up. Deaths due to CML progression were absent. The Sokal risk group was a reliable factor influencing MMR loss (p ≤ 0.05). The cumulative recovery rate for deep MR after resumption of TKI use was 73 and 100% at 12 and 24 months, respectively, with a median follow-up of 24 months (1 to 116 months). Deep MR recovered at a later time when the therapy was resumed more than 30 days after MMR loss. Conclusion. Safe follow-up is possible in about 50% of the patients with CML and stable deep MRs without TKI therapy. The introduction of this approach into clinical practice requires regular molecular genetic monitoring and organizational activities. Biological factors in maintaining remission after TKI discontinuation need to be separately studied.

Aim. To evaluate the efficiency of interferon (IFN) therapy in patients with essential thrombocythemia (ET) and polycythemia vera (PV). Subjects and methods. A total of 61 patients (41 with ET and 20 with PV) were examined. Prior to study enrolment, 44 (72%) patients with ET or PV received one or other therapy (aspirin was not taken into account). The mean Jak2V617F mutant allele at baseline was 23% (6—54%) in the patients with ET and 40% (11—88%) in those with PV. The median time from diagnosis to enrollment was 49 months. Results. The paper presents the clinical and molecular findings of long-term INF-α therapy in patients with ET or PV. The median follow-up was 52 months. Recombinant IFN-α2 showed its ability to induce complete hematologic remission (ET (76%), PV (70%)) and a complete molecular response. 22 (69%) out of 32 patients were noted to have a smaller number of cells with the Jak2V617F mutation. In the patients with PV and in those with ET, the relative reduction in the proportion of cells with the Jak2V617F mutant gene averaged 85% and 56% of the baseline values, respectively. There was a reduction in the proportion of cells expressing the Jak2V617F mutation in both the ET (from 12 to 2.2%; p=0.001) and PV (from 32.7% to 3.2%) groups (р=0.001). Ten (31%) patients achieved a deep molecular remission (≤2% Jak2V617F allele); among them, 5 patients were not found to have Jak2V617F mutation. The obtained molecular response remained in 7 of the 10 patients untreated for 11 to 86 months. The long-term treatment with IFN-α led to normalization of the morphological pattern of bone marrow in 5 of the 7 PV or ET patients. Conclusion. Significant molecular remissions achieved by therapy with recombinant interferon-α2 confirm the appropriateness of this treatment option in in the majority of patients with ET or PV.

AIM. To assess the main epidemiological characteristics of chronic myeloid leukemia (CML) in the Russian Federation. MATERIALS AND METHODS. A planned epidemiological prospective study was conducted in 2009-2012 in 6 Russian regions with the total number of 10.1 million inhabitants, which notified all new CML cases. RESULTS. The unstandardized (unnormalized, baseline) recorded incidence of CML in the examined regions was 0.58 per 100,000 annually. Its standardized (normalized) incidence was 0.70 for the WHO standard population and 0.72 for the European standard population. The regional variations in the incidence were 0.44 to 0.69. The structural analysis of the incidence in the age strata indicated that the overall morbidity was less due to the decreased rate of registration in old age groups. The morbidity rates in patients aged less than 60 years were nearly similar to the European rates; those in patients aged over 70 years were almost 10 times lower. The lower rate of detection and screening diagnosis of CML in pensioners in primary health care is discussed. CONCLUSION. The data obtained in this study may serve as the starting point for monitoring the CML epidemiological situation.

AIM. To determine the clinical features of multiple primary tumors (MPT) in patients with hemoblastoses, to develop treatment policy for synchronous and metachronous tumors, and to determine the impact of chemotherapy for one disease on the course and prognosis of another one. MATERIALS AND METHODS. The investigation included 20 patients with multiple primary synchronous and metachronous myeloid and lymphoid tumors, who had been followed up at the Outpatient Department of the Hematology Research Center, Ministry of Health of the Russian Federation. The distribution of patients by nosological entities was as follows: 17 (85%) patients with myeloproliferative diseases (MPDs) concurrent with lymphoproliferative diseases (LPDs) and 3 (15%) with two types of MPD. A special group comprised 3 patients who successively developed 3 malignant diseases: cancer/B-cell chronic lymphocytic leukemia (B-CLL)/Ph-positive chronic myeloid leukemia (Ph+CML); cancer/polycythemia vera (PCV)/B-CLL; cancer/essential thrombocythemia (ETC)/multiple myeloma (MM). RESULTS. The Outpatient Department of the Hematology Research Center, Ministry of Health of the Russian Federation, followed up 20 patients with synchronous and metachronous tumors in 1996 to 2013. The patients' age was 42 to 82 years (64 years). The female/male ratio was 1:1.2. Metachronous tumors were 1.5-fold higher than synchronous ones. The time to detection of secondary hemoblastosis averaged 3.3 years; the longest interval was 14 years; the mean coexistence of 2 tumors was 4.8 years (1-11 years). The total length of the follow-up was 8 years (1-19 years). Among them, there were 17 (85%) patients with 2 chronic hematologic tumors with a myeloid or lymphoid phenotype; 3 (15%) of the 20 patients had 3 malignant diseases (cancer/ B-CLL)/Ph+CML, cancer/PCV/B-CLL, cancer/ETC/MM. In the group of 17 patients, 13 (76%) were diagnosed as having Ph-negative MPDs (PCV in 4 patients, primary myelofibrosis in 4, ETC in 4, undifferentiated MPD in1) and 4 (24%) patients had Ph+CML. This patient group was found to have the following LPDs: CLL in 5 (30%), hairy cell leukemia in 1 (5%), paraproteinemic hemoblastoses in 11 (65%). MPD preceded LPD in 8 (47%) patients; the development interval between two tumors averaged 6 years (1 to 14 years). LPD preceded MPD in 3 (18%) patients; the interval averaged 5 years (2 to 17 years). MPD and LPD appeared synchronously in 6 (35%) patients. CONCLUSION. The fact that 2 malignancies or more may occur in one patient determines the need for a careful follow-up of patients with blood system diseases. The activity of one hematologic disease or another is a leading criterion for choosing a therapeutic tactic.

Aim. To investigate factors determining prognosis and efficacy of induction therapy including interferon-alpha-2b (intron-A, Schehng Plough) in patients at an early chronic stage of Ph-positive chronic myeloid leukemia (CML) as shown by histomorphological examination. Material and methods. The analysis covered 52 CML patients treated at an early chronic phase with intron-A in a standard daily dose 5 IU/m2 in combination with low-dose cytosinearabinoside (10 mg/m2, s.c. , daily for 10 days of each month). The treatment efficacy was assessed by the international criteria of complete and partial hematological remission and cytogenetic response. The cytogenetic study employed the direct method, even and G-differential staining, fluorescent hybridization in situ (FISH). The sections were stained with hematoxilin-eosine by Gomori, van Gieson. Histological samples were examined with histomorphometry. Immunohistochemical examination was made on paraffin sections using a panel of monoclonal antibodies CD3, CD4, CDS, CD20, NK, PCNA, Ki-67 (Dako, Denmark). Results. Repeated assessment of histomorphological parameters such as erythroid lineage, degree of myelofibrosis and reduction of leukemic population indicate the treatment efficacy. Estimation of the level of leukemic population proliferation in trephine biopsies from CML patients with monoclonal antibodies PCNA and Ki-67 before the treatment is prognostically significant as it further correlates with the cytogenetic response (r = 0.821, p = 0.000000). Conclusion. It is valid to study histomorphological picture of CML to prognosticate and assess treatment efficacy with standard doses of interferon-alpha with high probability.

Aim. To conduct molecular-cytogenetic monitoring of bone marrow cells in different regimens of chronic myeloid leukemia (CML) treatment. Material and methods. A total of 651 samples of bone marrow from 319 CML patients were studied. 229patients receivedpolychemotherapy and 90patients - interferon-alpha. Primary examination and monitoring of the treatment efficacy were performed using G-differential chromosome staining. Fluorescent in situ hybridization (FISH) was made in 75% cases. Results. Interferon therapy resulted in a significant increase in the number of complete and significant cytogenetic responses. With aggravation of the disease the above responses occurred less frequently while minor and no response are encountered more often. Treatment with interferon-alpha in combination with chemotherapy is much more effective than monotherapy with interferon. Conclusion. G-differential chromosome staining karyotypes metaphases and detects clonal chromosome restructuring. Molecular-cytogenetic methods study chromosome restructuring at DNA level. FISH detects chimeric gene bcr/abl in cases when Ph-chromosome is not detectable by standard cytogenetic methods.