Thrombosis and survival in essential thrombocythemia: a regional study of 1,144 patients.

To identify prognostic factors affecting thrombosis-free survival (TFS) and overall survival (OS), we report the experience of a Regional cooperative group in a real-life cohort of 1,144 patients with essential thrombocythemia (ET) diagnosed from January 1979 to December 2010. There were 107 thrombotic events (9.4%) during follow-up [60 (5.3%) arterial and 47 (4.1%) venous thromboses]. At univariate analysis, risk factors for a shorter TFS were: age >60 years (P < 0.0054, 95% CI 1.18-2.6), previous thrombosis (P < 0.0001, 95% CI 1.58-4.52) and the presence of at least one cardiovascular risk factor (P = 0.036, 95% CI 1.15-3.13). Patients with a previous thrombosis occurred ≥24 months before ET diagnosis had a shorter TFS compared to patients with a previous thrombosis occurred <24 months (P = 0.0029, 95% CI 1.5-6.1); furthermore, patients with previous thrombosis occurred <24 months did not show a shorter TFS compared with patients without previous thrombosis (P = 0.303, 95% CI 0.64-3.21). At multivariate analysis for TFS, only the occurrence of a previous thrombosis maintained its prognostic impact (P = 0.0004, 95% CI 1.48-3.79, RR 2.36). The 10-year OS was 89.9% (95% CI 87.3-92.5): at multivariate analysis for OS, age >60 years (P < 0.0001), anemia (P < 0.0001), male gender (P = 0.0019), previous thromboses (P = 0.0344), and white blood cell >15 × 10(9) /l (P = 0.0370) were independent risk factors. Previous thrombotic events in ET patients are crucial for TFS but their importance seems related not to the occurrence per se but mainly to the interval between the event and the diagnosis.

Role of treatment on the development of secondary malignancies in patients with essential thrombocythemia.

Aim of this study is to explore the role of different treatments on the development of secondary malignancies (SMs) in a large cohort of essential thrombocythemia (ET) patients. We report the experience of a regional cooperative group in a real-life cohort of 1026 patients with ET. We divided our population into five different groups: group 0, no treatment; group 1, hydroxyurea (HU); group 2, alkylating agents (ALK); group 3, ALK + HU sequentially or in combination; and group 4, anagrelide (ANA) and/or α-interferon (IFN) only. Patients from groups 1, 2, and 3 could also have been treated either with ANA and/or IFN in their medical history, considering these drugs not to have an additional cytotoxic potential. In all, 63 of the 1026 patients (6%) developed 64 SM during the follow-up, after a median time of 50 months (range: 2-158) from diagnosis. In univariate analysis, a statistically significant difference was found only for gender (P = 0.035) and age (P = 0.0001). In multivariate analysis, a statistically significant difference was maintained for both gender and age (gender HR1.7 [CI 95% 1.037-2.818] P = 0.035; age HR 4.190 [CI 95% 2.308-7.607] P = 0.0001). The impact of different treatments on SMs development was not statistically significant. In our series of 1026 ET patients, diagnosed and followed during a 30-year period, the different therapies administered, comprising HU and ALK, do not appear to have impacted on the development of SM. A similar rate of SMs was observed also in untreated patients. The only two variables which showed a statistical significance were male gender and age >60 years.