Cytoreductive Therapeutic Approach in the Essential Thrombocythemia (ET) Patients of the Registro Italiano Trombocitemia (RIT): Preliminary Data
Authors: Gugliotta Luigi , Tieghi Alessia , Candoni Anna , Lunghi Monia , Gaidano Gianluca , Passamonti Francesco , Rumi Elisa , Dragani Alfredo , Radaelli Franca , Iurlo Alessandra , Specchia Giorgina , Carluccio Paola , Scalzulli Potito Rosario , Melillo Lorella , Martinelli Vincenzo , Ciancia Rosanna , Randi Maria Luigia , Vannucchi Alessandro , Antonioli Elisabetta , De Biasi Ercole , Palmieri Fausto , Latagliata Roberto , Santoro Cristina , Liberati Anna Marina , Gubbiotti Marta , Rupoli Serena , Scortechini Anna Rita , Villa Maria Rosaria , Cacciola Rossella R , Cacciola Emma , Pierri Ivana , Salvucci Marzia , Cristofalo Claudio , Cilloni Daniela , Vianelli Nicola , Federici Augusto B. , Falanga Anna , Ruggeri Marco 
Published: April 2020

Background: the Registro Italiano Trombocitemia, that is a GIMEMA project, has been activated to registry Italian Essential Thrombocythemia (ET) patients, to improve the diagnosis appropriateness (WHO criteria), to verify the prognostic value of the clinical and biological parameters, to evaluate the compliance to the therapeutical Italian guidelines (1), and to create a network for activation of new studies.

Objective: this analysis is mainly devoted to describe the ET patients registered in the RIT and to evaluate the therapeutic approach adopted in the 102 participating hematological centers.

Material and methods: two thousand and fifteen ET patients have been registered after the written informed consent was obtained, and data validation by various expert panels is in progress. This preliminary report considers 1785 patients, diagnosed mainly (1078, 60.4%) since the publication in the year 2004 of the ET therapy Italian guidelines (1).

Results: the patients, 678 (38%) males and 1107 (62%) females, showed at diagnosis: age 60.3 ± 16.8 years with higher values in males than in females (61.7 ± 15.3 vs. 59.4 ± 17.7, p&lt;0.05), being the patients below 40 years 14% and those over 70 years 33% of cases; PLT count (109/L) 846 ± 309 with lower values in males than in females (813 ± 261 vs. 866 ± 334, p&lt;0.002), and with values 1001–1500 and over 1500 in 16% and 4% of cases, respectively; WBC count (109/L) 9.1 ± 2.9, without difference by sex, and with values 12–15 in 10% and over 15 in 3% of cases; Hgb (g/dL) 14.2 ± 1.6 with higher values in males than in females (14.8 ± 1.5 vs. 13.8 ± 1.5, p&lt;0.001), and with values over 16.5 in 8.5% of males and 2.7% of females, respectively; splenomegaly in 488 (27%), echo-documented in 324 cases (18%); history of hemorrhage and thrombosis in 90 (5%) and 325 (19%) of cases, respectively; disease-related symptoms in 41% and general thrombotic risk factors in 93% of cases, respectively. The WHO 2001 diagnostic criteria were reported for 33% of cases observed before the year 2004 and for 53 % of cases observed since the year 2004. Detailed data at diagnosis were reported as follows: bone marrow biopsy in 1087 cases (61%) with a frequency of 51% and 68% before and since the year 2004, respectively; bcr-abl study in 1045 cases (59%); cytogenetics in 828 cases (46%) with karyotype abnormalities in 27 patients (3%). The JAK2 V617F mutation, searched in 574 cases (32%), was observed in 320 of them (56%). The patient follow-up was 4.5 ± 4.5 years with a total of 5245 pt-yrs. During the follow-up the hemorrhagic events were 5.7% (1.3/100 pt-yrs), being the major events 1.9% (0.4/100 pt-yrs); the thrombotic complications were 14.9 % (3.3/100 pt-yrs), resulting the major arterial 9.4% (2.1/100 pt-yrs), the major venous 3.5% (0.8/100 pt-yrs) and the minor thrombosis 2% (0.4/100 pt-yrs). An antiplatelet treatment, almost always with low dose aspirin, was performed in 75% of the patients, without significant difference in the cases diagnosed before and since the 2004. A cytoreductive treatment was done with use of Hydroxyurea (HU, 64%), Interferon alpha (IFN, 16%), Anagrelide (ANA, 15%), Busulfan (BUS, 4%), and Pipobroman (PIPO, 2 %). In the ET patients diagnosed since the year 2004 respect those diagnosed before, it was observed a decrease in the use of all the cytoreductive drugs, particularly BUS (−62%), IFN ((−62%), and ANA ((−68%). The use of the cytoreductive drugs was related to the patient mean age (years): BUS (76), PIPO (72), HU (67), ANA (53), IFN (48). In the patients diagnosed since the 2004 as compared with those before 2004, the mean age of the treated patients increased for BUS (from 69 to 81 yrs, p&lt;0.001) and for HU (from 64 to 69 yrs, p&lt;0.001) while it decreased for IFN (from 49 to 46 yrs, p&lt;0.05).

Conclusion: in the analyzed patients of the ET Italian registry the diagnosis appropriateness resulted improved in the cases observed since the year 2004 respect those observed before, with an increase of bone marrow biopsies from 51% to 68% of patients. Moreover, in accord with the ET therapy Italian guidelines, the use of the cytoreductive drugs was less frequent in the patients diagnosed since the year 2004 than before (particularly for BUS, IFN, and ANA) and the more safe molecules IFN and ANA were preferentially deserved to the younger patients.