Greek Registry of Myelofibrosis: Baseline Characteristics and Therapeutic Strategy

The Greek Registry of Myelofibrosis (MF) is held under the auspices of the Acute Leukemias and Myeloproliferative Neoplasms Study Group of the Hellenic Society of Hematology. The preliminary results after two years of retrospective data collection are presented. The total number of patients included is 226, from 10 Greek sites; the initial diagnosis was made between 1975 and 2013.

The male to female ratio was 1.66. Median age at diagnosis was 69 years (range 25-88). In 26% of patients myelofibrosis was secondary to pre-existing hematological malignancy (essential thrombocythemia in 60%, polycythemia vera in 31%). The most prevalent presenting symptoms as reported by the treating hematologist were related to anemia (48%), enlarged spleen (33%), leukocytosis (18%) or thrombocytosis (16%) in routine blood counts examination and beta-symptoms (14%), followed by thrombocytopenia (7.3%), leukopenia (5.3%), thrombosis (3.4%), hemorrhage (2.4%), erythremia (1.5%). As documented in patient records at diagnosis, median platelet counts (PLT) were 283x10⁹/L, hemoglobin (Hb) 10.3 g/dL, white blood cell counts (WBC) 10.5 x10⁹/L and the spleen was palpable in 86% of patients. According to the International Prognostic Score System (IPSS), patients were categorized as low risk (15.8%), intermediate-1 (32.3%), intermediate-2 (32.3%) and high risk (19.6%). Molecular studies were performed in 77 patients (34% of total) and 69% of them were positive for the JAK2-V617F mutation.

The therapeutic strategy in myelofibrosis is dictated by the symptoms present and can be a combination of agents. In the Greek Registry, all but 7% of patients have required treatment. First-line therapy was a single agent in 68% (hydroxyurea 34%, erythropoetin 19%, androgen 11%, interferon 4%, corticosteroids 3%, ruxolitinib 2%) and a drug combination in the remaining 32%. Taking combinations into account, hydroxyurea was given to 41%, erythropoetin to 31%, androgens to 16%, corticosteroids to 8% and anagrelide to 2% of patients. In second-line therapy, combinations were administered to 50% of patients and they included erythropoetin (27%), androgens (22%), hydroxyurea (15%) or corticosteroids (15%); monotherapy with interferon was given to 6% and ruxolitinib to 4% of patients. At any time during the disease course, splenectomy was performed in 5% and spleen irradiation in 12% of patients for symptom relief.

Data for secondary malignancies were available in 170 patients. Acute leukemia occurred in 8% and solid tumor in 5% of patients.

Survival information is available for 147 patients. Median overall survival was 4.46 years, whereas 5- and 10-year survival rates were 45.3% and 11.5% respectively.

The aim of the registry and the subsequent data analysis is to convey the practice of managing the disease. Moreover, useful conclusions can be reached regarding to the patients’ responsiveness to therapy and the parameters that correlate with overall survival and disease progression.