Clinical and Prognostic Features of Essential Thrombocythemia: Comparison of 2001 WHO Versus 2008/2016 WHO Criteria in a Large Single-center Cohort

BACKGROUND

According to 2008/2016 classification of the World Health Organization (WHO), a platelet (PLT) count ≥ 450 × 10⁹/L, reduced from the previously published WHO 2001 indicated level ≥ 600 × 10⁹/L, was considered the new PLT threshold for the diagnosis of essential thrombocythemia (ET).

PATIENTS AND METHODS

To validate this important diagnostic change in a setting of current clinical practice, we retrospectively analyzed clinical and hematologic features at diagnosis and during follow-up of 162 patients with ET, diagnosed in our center from January 2008 to December 2017. We subdivided patients according to PLT value at baseline into Group A (PLT ≥ 600 × 10⁹/L) (124 patients; 76.5%) and Group B (PLT ≥ 450 × 10⁹/L < 600 × 10⁹/L) (38 patients; 23.5%).

RESULTS

Among clinical features, only the median value of leukocytes (P < .001) was significantly higher in Group A. Cytostatic treatment was administered in 103 patients, with a significantly higher rate in patients of group A (P < .001). After a median follow-up of 42.4 months (interquartile range, 22.1-70.6 months), 8 thrombotic events were recorded in the entire cohort, without differences between the 2 groups (P = .336). The 5-year overall survival (OS) of the entire cohort was 96.9% (95% confidence interval, 92.6%-100%), without differences between the 2 groups (P = .255).

CONCLUSIONS

Our data indicate a substantial homogeneity among patients with ET regardless of the PLT count at diagnosis, thus confirming the usefulness of the 2008/2016 WHO diagnostic criteria.

Long-term follow-up of late chronic phase chronic myeloid leukemia patients treated with imatinib after interferon failure: a single center experience

We report the long-term outcome of 139 patients treated with imatinib in late chronic phase after IFN failure. Median follow-up was 16.6 years and the estimated 18-year OS was 64.8%. 18-year EFS and PFS were 69% and 64.4%, respectively. Fifty (36%) patients stopped imatinib, 72% received a second line. b2a2 transcript was associated with a significantly inferior 18-year OS (p = 0.008), FFS (p = 0.036), PFS (p = 0.013) compared to the b3a2 type, whilst the type of transcript did not influence the time to response achievement. Failure to achieve MMR at 12 months significantly reduced the chance of reaching a DMR (p = 0.001). Imatinib discontinuation after achieving a sustained deep molecular response was attempted in 14 patients; 12 (86%) are still in treatment-free remission (TFR) at the last follow-up. Our experience confirms the long-term efficacy of imatinib after IFNα failure in real-life setting and documents the possibility of attempting a TFR in this subset of patients.

Real-life comparison of nilotinib versus dasatinib as second-line therapy in chronic phase chronic myeloid leukemia patients

Tyrosine kinase inhibitors (TKIs), the backbone of treatment for chronic phase chronic myeloid leukemia patients (CP-CML), have changed the long-term outcome of the disease. Nonetheless, over 20% of patients fail front-line therapy due to intolerance or resistance. A head-to-head comparison of dasatinib and nilotinib as second-line treatment outside of sponsored clinical trials has not been reported. We retrospectively analyzed 131 CP-CML patients who, after front-line imatinib failure, switched to a second-line therapy with nilotinib (59, 45%) or dasatinib (72, 55%). Median duration of second-line treatment was 33 months (range 2-100). The reason for switching therapy was resistance in 83.2% and intolerance in 16.8% of patients. The overall survival of the entire cohort at 7 years was 78.9%, while it was 72% and 85.6% for patients treated with dasatinib and nilotinib, respectively (p=0.287). With regard to efficacy after 12 months of treatment, 108 patients were evaluable for molecular response: 47% achieved a major molecular response and 18.2% a deep molecular response with dasatinib, compared to 38% and 16.2% with nilotinib (p=ns). We observed 35% of grade 3-4 adverse events, more frequently in the dasatinib group (47%) compared to the nilotinib group (22%), without affecting molecular responses. Our study suggests that, in the real-life setting, dasatinib and nilotinib used as second-line treatment in CP-CML are equally effective, with high molecular response rates and an acceptable tolerability.

Predictive factors for response and survival in elderly acute myeloid leukemia patients treated with hypomethylating agents: a real-life experience

Predictive factors of response to hypomethylating agents (HMA) in elderly acute myeloid leukemia (AML) patients remain unclear in the real-life setting and no direct comparison between azacitidine (AZA) and decitabine (DEC) has been carried out. We retrospectively evaluated 110 AML patients treated with HMA (78 AZA, 32 DEC) as first-line therapy outside of clinical trials. Median age was 75 years (range 58-87). The median overall survival (OS) of the entire cohort was 8.0 months (95% CI 6.1-10), without significant differences among the subgroups: AZA 8.8 months vs DEC 6.3 months (p = 0.291). HMA treatment yielded an overall response rate (ORR) of 40% (AZA 37% vs DEC 47%, p = 0.237). A stable disease (SD) after 4 HMA cycles was not associated with a worse survival outcome compared with an early optimal response. Factors independently associated with a better OS were transfusion independence during treatment (p = 0.049), achievement of an optimal response to treatment (p < 0.001), and a baseline hemoglobin level ≥ 9.25 (p = 0.018). A bone marrow (BM) blast count ≥ 30% (p < 0.001) and a therapy-related AML (p = 0.008) remain poor survival predictors. Of the available biologic features, an adverse risk category according to the ELN classification was significantly associated with a shorter survival over the intermediate risk category (p = 0.034). Disease progression remains the primary cause of death. Infectious complications were more severe (p = 0.036) and occurred earlier (p = 0.006) in the DEC group compared with that of the AZA group. In conclusion, clinical prognostic factors associated to response and survival have been identified without significant associations concerning overall outcomes between the two HMAs.

Prognostic Significance of PET/CT in Patients with Chronic Lymphocytic Leukemia (CLL) Treated with Frontline Chemoimmunotherapy

The role of positron emission tomography/computed tomography (PET/CT) in identifying Richter Syndrome (RS) is well established, while its impact on the survival of patients with chronic lymphocytic leukemia (CLL) has been less explored. The clinical characteristics and PET/CT data of 40 patients with a biopsy-proven CLL who required frontline chemoimmunotherapy, FCR (fludarabine, cyclophosphamide, rituximab) in 20 patients, BR (bendamustine, rituximab) in 20, were retrospectively analyzed. Standardized uptake volume (SUV_max) values ≥ 5 were observed more frequently in patients with deletion 11q (p = 0.006) and biopsies characterized by a rate of Ki67 positive cells ≥ 30% (p = 0.02). In the multivariate analysis, the presence of large and confluent PCs emerged as the only factor with a negative impact on progression-free survival (PFS), and overall survival (OS). Deletion 11q also revealed a significant and independent effect on PFS. SUV_max values ≥ 5 showed no statistical impact on PFS while in multivariate analysis, they revealed a significant adverse impact on OS (median survival probability not reached vs. 56 months; p = 0.002). Moreover, patients with higher SUV_max values more frequently developed Richter Syndrome (p = 0.015). Our results show that higher SUV_max values identify CLL patients with a pronounced rate of proliferating cells in the lymph-node compartment, inferior survival, and an increased risk of developing RS.