Systemic mastocytosis in Croatia

Abstract

SUMMARY Aim The aims of this study were to identify patients with systemic mastocytosis (SM) in Croatia and to analyze their clinical characteristics. Patients and methods Patients with SM treated at eight hospitals in Croatia were retrospectively identified and their clinical characteristics, treatment patterns and outcomes were analyzed. Results Twenty patients were included, median age was 40.5years (range 24-77), and most were females (n=12) . Patients with indolent SM (ISM, n=11) predominated, followed by aggressive SM (ASM, n=4), smoldering SM (SSM, n=3) and SM with an associated hematological neoplastic disorder (SM-AHND, n=2). Only one patient (with ASM) did not have cutaneous involvement, and a significant proportion of SM patients had dyspepsia, allergic diathesis, bone pains and osteoporosis. Antihistamines were administered in the majority of the patients, whereas ten patients needed cytoreductive treatment (ISM, n=3, SSM n=2, ASM, n=4, SM-AHND, n=1). Most SM patients in need for cytoreduction received interferon alpha-2a (two ISM, one SSM and three ASM), two received steroids (one ISM and one SM-AHND), one received imatinib (SSM) and the last patient was treated with cladribine (ASM). All patients treated first-line with interferons and cladribine achieved partial remission, whereas two patients treated with imatinib and steroid were refractory. None of the patients discontinued interferon due to drug-related side-effects. After a median follow-up of 33 months, three patients died, one with ASM and two with SM-AHND.The median survival of ISM/SSM patients was higher than in ASM/SM-AHND patients in whom it was 105 months (p=0.009). Conclusion Clinical characteristics and treatment outcomes of SM patients in Croatia are comparable to those from large international centers. The most commonly administered cytoreductive drug in Croatia was interferon alpha-2a which was shown to be safe and effective.