Long-term outcomes of patients with refractory cytopenia of childhood under observation only Open Access

• Patients with RCC, normal karyotype and absence of severe cytopenia or a genetic predisposition can safely followed by observation-only

• The long-term persistence of cytopenia in RCC patients highlights continuous follow-up and transition to adult hematology care.

Refractory Cytopenia of Childhood (RCC) is a well-recognized type of bone marrow failure patients defined by persistent cytopenia, dysplastic changes and a unique histopathologic pattern in the bone marrow. While hematopoietic stem cell transplantation (HSCT) is generally indicated for patients with severe cytopenia or abnormal karyotype, a subset of RCC patients may be candidates for an observational approach. We evaluated the long-term outcome of RCC patients without evidence of a genetic predisposition who had a normal karyotype and had not received HSCT or immunosuppressive therapy (IST) within 2 years from diagnosis. The median age at diagnosis of the 100 patients analyzed was 10.9 (1.4-17.3) years. Eighty-four percent presented with a hypocellular bone marrow. Clonal evolution with abnormal karyotype occurred in three patients (3%), and one case progressed to myelodysplastic syndrome with excess blasts (MDS-EB). Three patients (3%) developed paroxysmal nocturnal hematuria. Overall, nine (9%) patients received HSCT, and the 5- and 10-year HSCT-free survival was 94% and 88%, respectively. At last follow-up, all patients were alive with a median follow-up time of 7.2 years. These results indicate that an observational approach is safe for selected RCC patients with a normal karyotype following an exclusion of a germline predisposition syndrome. However, persistence of cytopenia in most of these patients underscores the importance of long-term surveillance and transition to adult hematology care. NCT00047268, NCT00662090.