Malgorzata Calbecka

A single weekly dose of imatinib is sufficient to induce and maintain remission of chronic eosinophilic leukaemia in FIP1L1-PDGFRA-expressing patients

Hypereosinophilic syndrome (HES) is defined as chronic, unexplained hypereosinophilia with organ involvement. A subset of HES patients presents an interstitial deletion in chromosome 4q12, which leads to the expression of an imatinib‐responsive fusion gene, FIP1L1‐PDGFRA. These patients are diagnosed as chronic eosinophilic leukaemia (CEL). We treated seven CEL and HES patients, six of which expressed FIP1L1‐PDGFRA, with imatinib using initial daily doses ranging from 100 to 400 mg. In a remission maintenance phase, the patients were treated with imatinib once weekly. All imatinib‐treated patients achieved a complete haematological remission (CHR), and five of the six patients with FIP1L1‐PDGFRA expression exhibited molecular remission. The decreased imatinib doses were as follows: 200 mg/week in three patients, 100 mg/week in two patients and 100 mg/d in the remaining two patients. For remission maintenance, imatinib doses were set at 100 mg/week in five patients and 200 mg/week in two patients. At a median follow‐up of 30 months all patients remained in CHR and FIP1L1‐PDGFRA expression was undetectable in five of the six FIP1L1‐PDGFRA‐expressing patients. These data suggest that a single weekly dose of imatinib is sufficient to maintain remission in FIP1L1‐PDGFRA‐ positive CEL patients.

CD38 Gene Polymorphisms Contribute to Genetic Susceptibility to B-Cell Chronic Lymphocytic Leukemia: Evidence from Two Case-Control Studies in Polish Caucasians

Given the recent findings on the importance of CD38 signaling in the pathogenesis of B-cell chronic lymphocytic leukemia (B-CLL), we hypothesized that single nucleotide polymorphisms (SNP) in the CD38 gene may be related to B-CLL risk. We evaluated two potentially functional CD38 SNPs, intronic rs6449182 (184C>G) and missense rs1800561 (418C>T, Arg140Trp) in two hospital-based case-control studies (study A and validation study B). Genotyping was done using PCR-based assays in a total of 460 Polish Caucasian patients with B-CLL and 503 age-matched and gender-matched controls. We found that frequencies of both variant alleles (rs6449182 G and rs1800561 T) were significantly higher in B-CLL. In study A, logistic regression analysis revealed an association between B-CLL and genotypes: rs6449182 CG [odds ratio (OR), 3.57; 95% confidence interval (95% CI), 2.4-5.3], rs6449182 GG (OR, 5.2; 95% CI, 2.36-11.5), and rs1800561 CT (OR, 6.72; 95% CI, 1.5-30.1), although no homozygous rs1800561 TT genotype was detected in either study. These results were confirmed in study B, which showed an association between B-CLL and genotypes rs6449182 CG (OR, 4.00; 95% CI, 2.7-6.0), rs6449182 GG (OR, 12.84; 95% CI, 4.3-38.7), and rs1800561 CT (OR, 10.12; 95% CI, 1.3-81.6), and in the combined analysis of both studies. We also observed that rs6449182 G carriers had more advanced clinical stage (P = 0.002) and tended to be younger at diagnosis (P = 0.056). Furthermore, we found higher CD38 transcript levels and higher proportions of CD38-positive cells in carriers of rs6449182 G and rs1800561 T alleles (P < 0.05 for all comparisons). In conclusion, our data show that CD38 SNPs may affect CD38 expression and contribute to the increased risk of B-CLL carcinogenesis. (Cancer Epidemiol Biomarkers Prev 2009;18(3):945–53)

Real-life comparison of severe vascular events and other non-hematological complications in patients with chronic myeloid leukemia undergoing second-line nilotinib or dasatinib treatment

We retrospectively analyzed the rates of significant non-hematological adverse events (AEs) in 105 patients with chronic myeloid leukemia (CML) treated with second-generation tyrosine kinase inhibitor (TKIs) dasatinib or nilotinib used as second-line therapy in Polish tertiary care centers. Our analysis revealed that in a “real life setting,” nearly half of patients with CML on second-generation TKIs suffer from therapy complications. Grade 2–5 non-hematological AEs were observed in 40% of patients treated with nilotinib and in 42% treated with dasatinib (p = 0.83). Severe vascular events including peripheral artery occlusive disease (PAOD) occurred in 11% of patients on nilotinib and 4% on dasatinib (p = 0.16). Pleural effusion occurred more often in the dasatinib group (26%) than in the nilotinib group (2%) (p = 0.003). Importantly, most AEs occurred late, after more than 1 year of treatment. Since AEs are most often the reason for poor therapy compliance, careful monitoring of tolerability is crucial for an optimal treatment response in CML.

Clinical characteristics of patients with chronic eosinophilic leukaemia (CEL) harbouring FIP1L1-PDGFRA fusion transcript--results of Polish multicentre study.

A small subgroup of patients with hypereosinophilic syndrome (HES) demonstrates imatinib‐sensitive fusion transcript—the FIP1L1‐PDGFRA (F/P+). These cases are currently diagnosed as chronic eosinophilic leukaemia (CEL). In this paper, we screened 77 patients to estimate the frequency of FIP1L1‐PDGFRA transcript among patients with unexplained, long‐term hypereosinophilia exceeding 1.5 × 109/L and to analyse the clinical and serological features in F/P+ CEL population. The FIP1L1‐PDGFRA chimeric protein was detectable in 16 (14 males and 2 females) out of 77 examined HES patients (20%) by RT‐PCR. Two patients suffered from cough at diagnosis. Three out of 16 (18%) patients had no organ involvements, in 5‐one organ was affected and in the remaining eight cases—at least two. Eosinophilic organ damage/dysfunction identified splenomegaly in the majority of studied patients. We compared clinical and serological features between CEL F/P+ (n = 16) and HES (n = 61) patients. F/P+ cases had significantly increased WBC and absolute eosinophil count (AEC) at diagnosis (p = 0.008 and 0.02), whereas platelet count was decreased in this population (p = 0.03). Serum B12 and tryptase levels were increased (p = 0.002 and 0.004) in CEL F/P+ patients when compared to HES cases whereas serum IL‐5 levels were significantly increased in the latter group (p = 0.01). Male gender and splenomegaly occurred more frequent in CEL F/P+ population (p = 0.002 and 0.0007, respectively). Additionally, patients with F/P+ CEL (n = 16) were compared with F/P− CEL (n = 8). The latter group, was significantly older, had lower AEC and higher platelet count. In conclusion, significant clinical symptoms are infrequent present and splenomegaly remains the most common organ involvement in patients with CEL expressing F/P fusion transcript. Our study confirmed the long‐term remission on imatinib in this patient population. Copyright

Weekly imatinib dosage for chronic eosinophilic leukaemia expressing FIP1L1‐PDGFRA fusion transcript: extended follow‐up

Bogani, C., Ponziani, V., Guglielmelli, P., Desterke, C., Rosti, V., Bosi, A., Le Bousse-Kerdiles, M.C., Barosi, G. & Vannucchi, A.M. (2008) Hypermethylation of CXCR4 promoter in CD34+ cells from patients with primary myelofibrosis. Stem Cells, 26, 1920–1930. Cervantes, F., Mesa, R. & Barosi, G. (2007) New and old treatment modalities in primary myelofibrosis. Cancer Journal, 13, 377–383. Jones, L.C., Tefferi, A., Idos, G.E., Kumagai, T., Hofmann, W.K. & Koeffler, H.P. (2004) RARbeta2 is a candidate tumor suppressor gene in myelofibrosis with myeloid metaplasia. Oncogene, 23, 7846–7853. Quintas-Cardama, A., Tong, W., Kantarjian, H., Thomas, D., Ravandi, F., Kornblau, S., Manshouri, T., Cortes, J.E., Garcia-Manero, G. & Verstovsek, S. (2008) A phase II study of 5-azacitidine for patients with primary and post-essential thrombocythemia/polycythemia vera myelofibrosis. Leukemia, 22, 965–970. Shi, J., Zhao, Y., Ishii, T., Hu, W., Sozer, S., Zhang, W., Bruno, E., Lindgren, V., Xu, M. & Hoffman, R. (2007) Effects of chromatinmodifying agents on CD34+ cells from patients with idiopathic myelofibrosis. Cancer Research, 67, 6417–6424. Tefferi, A., Huang, J., Schwager, S., Li, C.Y., Wu, W., Pardanani, A. & Mesa, R.A. (2007a) Validation and comparison of contemporary prognostic models in primary myelofibrosis: analysis based on 334 patients from a single institution. Cancer, 109, 2083–2088. Tefferi, A., Thiele, J., Orazi, A., Kvasnicka, H.M., Barbui, T., Hanson, C.A., Barosi, G., Verstovsek, S., Birgegard, G., Mesa, R., Reilly, J.T., Gisslinger, H., Vannucchi, A.M., Cervantes, F., Finazzi, G., Hoffman, R., Gilliland, D.G., Bloomfield, C.D. & Vardiman, J.W. (2007b) Proposals and rationale for revision of the World Health Organization diagnostic criteria for polycythemia vera, essential thrombocythemia, and primary myelofibrosis: recommendations from an ad hoc international expert panel. Blood, 110, 1092–1097. Wang, J.C., Chen, W., Nallusamy, S., Chen, C. & Novetsky, A.D. (2002) Hypermethylation of the P15INK4b and P16INK4a in agnogenic myeloid metaplasia (AMM) and AMM in leukaemic transformation. British Journal of Haematology, 116, 582–586.

The early reduction of leukemic blasts in bone marrow on day 6 of induction treatment is predictive for complete remission rate and survival in adult acute myeloid leukemia; The results of multicenter, prospective Polish adult leukemia group study

The aim of this study was to prospectively evaluate the impact of early bone marrow response on complete remission (CR) rate and long-term outcome in adults with acute myeloid leukemia. Bone marrow cytology was assessed on day 6 of induction treatment in 164 patients, revealing the presence of ≥5% blasts in 61 cases. In this subgroup the CR rate was significantly lower compared to the remaining patients (P < 0.00001) resulting in decrease of the overall survival (P = 0.002). Persistence of ≥5% blasts in bone marrow on day 6 of induction is an easily available surrogate marker to be used for treatment decisions.

Cladribine added to daunorubicin-cytarabine induction prolongs survival of FLT3-ITD+ normal karyotype AML patients.

To the editor: Internal tandem duplication in the FLT3 gene ( FLT3- ITD) has been recognized as a marker conferring poor outcome in patients with normal karyotype acute myeloid leukemia (NK-AML).[1][1] Because of the inferior outcome of FLT3- ITD+ NK-AML patients when treated with standard

A risk of essential thrombocythemia in carriers of constitutional CHEK2 gene mutations.

Germline mutations of the CHEK2 gene have been reported in some myeloid and lymphoid malignancies, but their impact on development of essential thrombocythemia has not been studied. In 16 out of 106 (15.1%) consecutive patients, newly diagnosed with essential thrombocythemia, we found one of four analyzed CHEK2 mutations: I157T, 1100delC, IVS2+1G>A or del5395. They were associated with the increased risk of disease (OR=3.8; P=0.002). The median age at ET diagnosis among CHEK2+/JAK2V617F+ patients was seven years lower than that among CHEK2−/JAK2V617F+ (52 vs. 59 years; P=0.04), whereas there was no difference in the medians of hematologic parameters between these groups. The results obtained suggest that CHEK2 mutations could potentially contribute to the susceptibility to essential thrombocythemia. The germline inactivation of CHEK2, as it seems, has no direct impact on the development of disease, but it could cause disruption of cell cycle checkpoints and initiate or support the cancerogenic process of essential thrombocythemia at a younger age.

The germline mutations of the CHEK2 gene are associated with an increased risk of polycythaemia vera

The molecular mechanisms underlying the development of myeloproliferative neoplasms (MPNs) are still not sufficiently well understood, although the association of MPNs pathogenesis with some gene alterations, especially somatic, have been reported (Tefferi, 2010; Bench et al, 2013). Recently, we demonstrated a strong association of germline mutations in the CHEK2 tumour suppressor gene with the increased risk of essential thrombocythaemia (ET) (Janiszewska et al, 2012). CHEK2 plays a key role in cell cycle regulation, coordination of DNA repair and apoptosis (Bartek & Lukas, 2003). In the general Polish population, four founder CHEK2 mutations (p.I157T, c.444+1G>A, c.1100delC and del5395) occur with 5 8% frequency, therefore it is possible to provide a reliable assessment of cancer risk in patient groups (Cybulski et al, 2007). The present study investigated the impact of these mutations on the risk of polycythaemia vera (PV). Such research has not been carried out so far. We also analysed the relationship between CHEK2 mutations and the JAK2 p.V617F mutation, and their relation to patient age, haematological features at PV diagnosis and a family history of cancer. The analysis included 106 consecutive patients, newly diagnosed with PV according to World Health Organization 2008 criteria (Tefferi & Vardiman, 2008) at two Polish haematology centres (Wrocław and Toru n). The median age of the cohort was 62 years. All molecular and statistical analyses were performed as previously described (Janiszewska et al, 2012). The gene mutations were investigated in DNA from peripheral blood (PB) and buccal swabs of patients, and in DNA from PB of 312 healthy persons, which formed the control group. The JAK2 p.V617F was present in 92 5% of patients, being homozygous in 27 6%. It was not found in buccal swabs of patients and in PB of controls. A CHEK2 mutation was found in 15 (14 1%) patients (Table I), 14 of whom were heterozygous and one was homozygous (p.I157T). The frequency of CHEK2 mutations was similar to that previously reported in ET patients (15 1%) (Janiszewska et al, 2012). All mutations were present both in DNA from PB and buccal swabs of patients, confirming their constitutional nature. The risk of PV was three times higher in CHEK2-positive patients, compared to both the control group [odds ratio (OR) = 3 0, P = 0 004] and general Polish population (OR = 2 7, P = 0 001) (Table I), and was similar to the previously reported risk of ET (Janiszewska et al, 2012). Thus, the estimated risk of PV and ET was found to be two times higher than the risk of breast cancer in women with CHEK2 mutations (Cybulski et al, 2007). The c.444+1G>A protein-truncating mutation was found at a frequency that was two times lower than the p.I157T missense mutation, but it was more strongly associated with the risk of PV. No patient had c.1100delC or del5395 (Table I). Both detected mutations are related to the highly conserved forkhead homology-associated (FHA) domain of the CHEK2 protein, functionally important for interactions with other proteins in response to DNA damage. The I157T protein variant has a disrupted ability to bind TP53 (p53) and BRCA1. The c.444+1G>A eliminates part of the FHA domain and the entire kinase activation domain, resulting in premature protein-truncation. These alterations, even in heterozygotes, may lead to reduction or loss of the gene function (Bartek & Lukas, 2003). Eight (53%) CHEK2-positive patients originated from families with at least one case of colon, stomach, breast, prostate or larynx cancer, and five (33%) from families with no known solid cancer. One of two remaining CHEK2-positive patients had a daughter with thrombocytopenia, and the mother of the second had acute leukaemia. No CHEK2 mutation was detected in one family with three consecutive generations of PV. JAK2 p.V617F was found in 13 CHEK2-positive patients. It this group, the median age at PV diagnosis was 7 years higher than in CHEK2-negative/JAK2 p.V617F-positive patients, but this difference was not statistically significant (Table II). Conversely, the median age at diagnosis in CHEK2-positive/JAK2 p.V617F-positive ET patients was 7 years lower than in CHEK2-negative/JAK2 p.V617F-positive cases, and this difference was statistically significant (P = 0 04) (Janiszewska et al, 2012). These results need to be corroborated in larger groups of patients, however they suggest that congenital CHEK2 mutations may have an impact on the later PV onset, and are associated with the neoplastic process in PV. The subgroups of patients with or without JAK2 p.V617F were too small for reliable statistical analysis. Significantly lower median levels of haemoglobin (P = 0 022) and haematocrit (P = 0 0009), i.e. basic parameters for a correct diagnosis of PV, were found in CHEK2positive/JAK2 p.V617F-positive patients compared to correspondence

Long-term results of the Polish Adult Leukemia Group PALG-CLL2 phase III randomized study comparing cladribine-based combinations in chronic lymphocytic leukemia

Abstract Long-term outcomes following newer therapies for chronic lymphocytic leukemia (CLL) have rarely been reported. This article presents the results of the final analysis of the Polish Adult Leukemia Group PALG-CLL2 study performed 10 years from final patient enrollment. With the extended follow-up time, it was found that cladribine (2-CdA)-based combinations CMC (2-CdA, cyclophosphamide, mitoxantrone) and CC (2-CdA, cyclophosphamide) administered as first-line treatment of progressive CLL resulted in significantly longer progression-free survival, but similar overall survival compared to 2-CdA monotherapy. Furthermore, the risk of potentially fatal late adverse events including infections, autoimmune complications and, particularly, secondary neoplasms was comparable among patients treated with CMC, CC or 2-CdA. The results of our analysis support the importance of long-term outcome monitoring of randomized trials in CLL.