Haemopoietic stem cell transplantation for advanced polycythaemia vera or essential thrombocythaemia

Ten patients with polycythaemia vera (PV) and nine with essential thrombocy thaemia (ET) received a haemopoietic stem cell transplant (HSCT) at the Fre d Hutchinson Cancer Research Center between May 1988 and March 2000. HSCT w as performed because of progression to the spent phase of the disease with myelofibrosis and splenomegaly in 10 patients and evolution into a myelodys plastic syndrome (MDS) or acute myelogenous leukaemia (AML) in nine patient s. Patients were 18-59 years old (median 43). The interval from diagnosis t o HSCT was 77-300 months (median 170). Seven patients were splenectomized b efore transplantation, and all but five had been treated with cytotoxic age nts. Eleven patients received a transplant from a related, and eight from a n unrelated, donor following conditioning with chemotherapy only or chemoth erapy plus total body irradiation regimens. All evaluable patients achieved sustained engraftment. Twelve patients are surviving 5-116 months (median 41) after transplant, 10 in continued complete remission, one in haematolog ical remission with residual marrow fibrosis and one with mixed haemopoieti c chimaerism currently receiving therapy with interferon. Seven patients (s ix with AML/MDS and one with myelofibrosis) died of transplant-related comp lications. These data show that HSCT can provide curative therapy for patie nts with PV and ET with advanced disease.