Acute myeloid leukemia (AML) is a malignant hematopoietic disease with poor clinical course and outcome. There is a constant need for new prognostic factors that could facilitate patient risk stratification. The aim of our research was to determine the phosphorylation levels of phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK) pathways in leukemic cells, their relation to P-glycoprotein (P-gp) expression/activity and their prognostic significance in adult de novo AML. A total of 118 patients with AML were enrolled in the study. In a multivariate Cox regression analysis we found that P-gp activity and Akt phosphorylation were independent poor prognostic factors of overall survival (OS). In contrast, phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) represented a favorable prognostic factor of OS and relapse-free survival (RFS). A negative correlation between P-gp activity and p38 phosphorylation level was found, implying a possible role of this MAPK pathway in P-gp regulation. In addition, we found correlation between Akt and p38 phosphorylation levels, indicative of co-activation of two signaling cascades in AML.

The only way to cure leukemia is by cooperative research. To optimize research, the European Leukemia Net integrates 105 national leukemia trial groups and networks, 105 interdisciplinary partner groups and about 1,000 leukemia specialists from 175 institutions. They care for tens of thousands of leukemia patients in 33 countries across Europe. Their ultimate goal is to cure leukemia. Since its inception in 2002, the European Leukemia Net has steadily expanded and has unified leukemia research across Europe. The European Leukemia Net grew from two major roots: 1) the German Competence Network on Acute and Chronic Leukemias; and 2) the collaboration of European Investigators on Chronic Myeloid Leukemia. The European Leukemia Net has improved leukemia research and management across Europe. Its concept has led to funding by the European Commission as a network of excellence. Other sources (European Science Foundation; European Leukemia Net-Foundation) will take over when the support of the European Commission ends

AimTo analyze the incidence and characteristics of venous thromboembolism (VTE) in Croatia.MethodsThe Croatian Cooperative Group for Hematologic Diseases conducted an observational non-interventional study in 2011. Medical records of patients with newly diagnosed VTE hospitalized in general hospitals in 4 Croatian counties (Šibenik-Knin, Koprivnica-Križevci, Brod-Posavina, and Varaždin County) were reviewed. According to 2011 Census, the population of these counties comprises 13.1% of the Croatian population.ResultsThere were 663 patients with VTE; 408 (61.54%) had deep vein thrombosis, 219 (33.03%) had pulmonary embolism, and 36 (5.43%) had both conditions. Median age was 71 years, 290 (43.7%) were men and 373 (56.3%) women. Secondary VTE was found in 57.3% of participants, idiopathic VTE in 42.7%, and recurrent VTE in 11.9%. There were no differences between patients with secondary VTE and patients with idiopathic VTE in disease recurrence and sex. The most frequent causes of secondary VTE were cancer (40.8%), and trauma, surgery, and immobilization (38.2%), while 42.9% patients with secondary VTE had ≥2 causes. There were 8.9% patients ≤45 years; 3.3% with idiopathic or recurrent VTE. Seventy patients (10.6%) died, more of whom had secondary (81.4%) than idiopathic (18.6%) VTE (P < 0.001), and in 50.0% VTE was the main cause of death. Estimated incidence of VTE in Croatia was 1.185 per 1000 people.ConclusionCharacteristics of VTE in Croatia are similar to those reported in large international studies. Improved thromboprophylaxis during the presence of risk factors for secondary VTE might substantially lower the VTE burden.

Paraffin-embedded histopathologic specimens, taken before the commencement of therapy from 14 low-grade and 21 high-grade malignant lymphoma patients, and 9 normal lymph nodes were utilized to analyze six cell DNA-related parameters. The flow cytometry technique was used to determine cell-cycle G0/G1, S and G2/M phases, and silver staining to enumerate nuclear organized regions (AgNORs); nucleus surface area was determined by an image-analyzing system. The six parameters and natural logarithm of cell proportion in the S-phase (LS) were determined according to the histologic tumor type and achievement of the first complete remission (CR). All parameters except cell proportion in G1/M cycle phase differed significantly with respect to histologic cell type, but were not related to the achievement of first CR. Inasmuch as the parameters significantly correlated with each other, multivariate discriminant analysis and proportional hazard regression were applied to estimate their discriminant/predictive values with respect to tumor malignancy. AgNORs proved to be far superior in all three clinical parameters, S-phase was significantly predictive for the achievement of first CR, and LS for tumor histology type. The statistical model applied narrowed down the analysis of seven parameters to two with respect to tumor histology type (AgNORs and LS) and achievement of first CR (AgNORs and S), but only to one for overall patient survival (AgNORs). Only the model for tumor histology type discrimination was statistically significant (R2 = 0.904, p < 0.001). It appears that AgNORs may be of utmost predictive importance for the clinical outcome in NHL.

3612 The AML-12 randomized phase III trial of the EORTC and GIMEMA Leukemia Groups assessed the efficacy and toxicity of HD-AraC (3 g/sqm/12 hrs for 4 days) combined with daunorubicin (50 mg/sqm/d for 3 days) and etoposide (50 mg/sqm/d for 5 days) vs SD-AraC (100 mg/sqm/d for 10 days) combined with the same drugs, in previously untreated AML < 61 year old patients (APL excluded). Patients (pts) in complete remission (CR) received consolidation consisting of AraC (500 mg/sqm/12 hrs for 6 days) and daunorubicin (50 mg/sqm/d for 3 days). Subsequently an allogeneic (allo-SCT) or autologous stem cell transplantation (auto-SCT) was planned according to donor availability and age. A 2nd randomization was performed after consolidation in pts without a donor: auto-SCT followed or not by low dose IL-2 (4-8 × 106 IU/d s.c. for 5 days per month) during one year. A total of 577 pts were required to be randomized for the 2nd question in order to reach 255 events (relapses or deaths) which would allow to detect a 11.5% increase in the 3-year disease-free survival (DFS) from 50% to 61.5% corresponding to hazard ratio (HR) = 0.70 (2-sided alpha=5%, statistical power=80%). Randomization was performed centrally; the 2nd randomization was stratified for induction treatment, cytogenetic/molecular genetic group, number of courses to reach CR, auto-SCT planned (No/Yes) and center. Intent-to-treat analysis was done in eligible pts. From 9/1999 till 1/2008, 2005 pts were randomized (891 by EORTC-LG and 1114 by GIMEMA). In addition 104 pts (GIMEMA) were registered to receive SD-AraC (+etoposide+daunorubicine) in induction. Due to insufficient reporting, 3 centers, who recruited 63 pts, have been excluded from the analysis. After 1 or 2 courses of induction, CR was achieved in 1500 pts. Between 4/2000 and 5/2008 544 pts have been randomized for the IL-2 question, of whom 528 (222 EORTC, 306 GIMEMA) met the eligibility criteria and were included in the analysis: 263 in IL-2, 265 in Observation (Obs) arm; the remaining pts have not been randomized due to prolonged hypoplasia after consolidation or after auto-SCT, or refusal of the patient or a planned allo-SCT. The two groups were well balanced with respect to the above mentioned stratification factors. Due to prolonged pancytopenia after auto-SCT, severe organ damage or infection after auto-SCT, early relapse or patient refusal, 165 pts actually received IL-2 and 197 pts were adequately documented in the Obs arm. During the first 4 months 82% of the pts in the IL-2 arm received a mean daily dose of 6 × 106 IU and 62% of the pts received the maximally required 20 s.c. injections; the remaining stopped due to relapse (22%) or toxicity (16%). During the second 4 months, out of 103 pts 82% in the IL-2 arm received a mean daily dose of 6 × 106 IU and 76% of the pts received the maximally required 20 s.c. injections; the remaining stopped due to relapse (15%), toxicity/refusal (6%) or other reasons (2%). During the third 4 months, among 79 of the pts in the IL-2 arm 80% received a mean daily dose of 6 × 106 IU and 85% of the pts received the maximally required 20 s.c. injections. Grade 3–4 toxicity was more frequent in the IL-2 compared to Obs arm and consisted of hypersensitivity (3% vs 0%), fatigue (7.9% vs 1%), rigor/chills (6.1% vs 0%), arthralgia/myalgia (3.6% vs 0%). For the total of 528 pts, the median follow-up from the 2nd randomization was 6 years. As of July 2011, a total of 308 events were reported: 150 (IL-2 arm) vs 158 (Obs arm); among them 277 relapses (137 vs 140) and 31 deaths without relapses (13 vs 18). The DFS from 2nd randomization was similar in the 2 groups: the 5-yr DFS rate was 44.2% (IL-2) vs 40.4% (Obs), hazard ratio (HR)=0.95, 95% CI (0.76,1.19), p=0.66. A total of 259 pts died: 128 (IL-2 arm) vs 131 (Obs. arm). The 5-yr overall survival rate was 52.2% (IL-2) vs 50.9% (Obs), HR=0.98, 95% CI (0.77,1.26), p=0.9. The initial remission induction treatment (received/randomized) did not have impact on the results after the 2nd randomization. Conclusion: This study shows that, with a median follow-up of 6 years, low dose IL-2 maintenance does not lead to a prolonged DFS and overall survival in pts with AML in first complete remission treated in the EORTC-GIMEMA AML12 trial. Disclosures: Muus: Amgen: Membership on an entity's Board of Directors or advisory committees. de Witte:Novartis: Consultancy, Honoraria, Speakers Bureau.