JUVENILE CHRONIC MYELOGENOUS LEUKEMIA - REPORT OF THE ITALIAN REGISTRY

Background. Since juvenile chronic myeloid leukemia (JCML) represents no more than 2% of leukemia in children, clinical and investigative ex perience of this disorder has been limited. In order to evaluate the d iagnostic criteria currently applied, to provide centralized facilitie s for blood culture and to collect data on treatment, and to propose a uniform treatment protocol in our country, a National Registry for JC ML was recently established in the <<Associazione Italiana di Ematolog ia Oncologia Pediatrica>> (AIEOP). Patients. Out of the 24 cases repor ted from 9/35 centres, 22 were considered sufficiently documented and were enrolled in the Registry. Clonogenic assay on marrow and peripher al blood cells was performed in all available cases. Results. Common f eatures were non-specific clinical (fever, splenomegaly, hepatomegaly, lymphadenomegaly) and hematologic alterations (anemia, thrombocytopen ia, leukocytosis usually <50x10(9)/l, monocytosis, circulating immatur e granulocytes, increased HbF, normal karyotype). In 11 out of 11 case s, in vitro blood cultures showed the spontaneous growth of CFU-C in t he absence of any exogenous source of colony-stimulating activity. Twe lve of the 22 patients (55%) are alive (probability of survival 47.7%) ; most patients were treated according to an acute myeloid leukemia-di rected schedule; 5/7 children treated with interferon were alive with disease after a median time of 29 months from diagnosis (range 8-95 mo nths); 4/5 children who underwent bone marrow transplantation were ali ve in complete remission 10, 24, 42 and 118 months, after the diagnosi s. Age < 1 year at presentation was the most significant prognostic fa ctor in terms of probability of survival (80% vs 28%; p = 0.0024). Con clusions. JCML must be considered in young children for whom acute leu kemia has been suspected but ruled out; in vitro cultures should be co nsidered mandatory to confirm the diagnosis. Age less than one year at the presentation was associated with prolonged survival. Only bone ma rrow transplantion was followed by prolonged disease-free survival, wh ereas intensive chemotherapy seemed not very effective and potentially associated with life-threatening complications. Interferon therapy ap pears to be a promising alternative to chemotherapy while the value of unrelated marrow donor is explored.