AIM: The aim of this work was to retrospectively analyze patients with Philadelphia-negative myeloproliferative neoplasms through evaluation of frequency and characteristics of second malignancies (other than acute leukaemia and myelodysplastic syndrome). PATIENTS AND METHODS: Records of 172 patients were reviewed; an analysis was performed on data from 66 patients treated with hydroxyurea, 105 patients treated with other cytoreductive therapy, and 25 patients without treatment. RESULTS: A higher occurrence of second malignancies was found in the group treated with hydroxyurea (7.6%; other cytoreduction: 1.2%; without therapy: 0). After a median follow-up of 89 months in the hydroxyurea group, 13 patients developed second cancer during hydroxyurea therapy, located on the skin (68.75%) and other sites (31.25%). CONCLUSION: The incidence of second malignancies during hydroxyurea therapy in our cohort patient was significantly higher than the incidence of malignancies in the Czech population of corresponding age.

Department of Haematology University Hospital Brno Jihlavska 20 625 00 Brno Czech Republic