Therapeutic effectiveness of ranimustine chemotherapy for elderly essential thrombocythemia

Background: We studied the clinical effectiveness of ranimustine (MCNU) chemotherapy for essential thrombocythemia (ET). Methods: MCNU chemotherapy was carried out in 14 ET patients who were 60 years of age or older, including six men and eight women. Their ages ranged between 61 and 88 years (median age: 73 years). The patients’ mean platelet count before the treatment was 1.157 ± 0.284 × 106/µL. Five of the studied patients had experienced a thrombotic episode, and one had a profuse epistaxis. Patients were treated mainly by intravenous administration of MCNU. In 12 patients, the platelet count was controlled to a level less than 500 × 103/µL, while in two patients, it was controlled to less than 700 × 103/µL. Results: Cerebral infarction occurred in only one patient during or after MCNU therapy. Even in the cases in which thrombosis had occurred before MCNU treatment, further thrombotic events occurred in only one case. In the patient with a profuse epistaxis, bleeding improved during treatment and normal platelet count was maintained after chemotherapy. Conclusion: It was suggested that MCNU chemotherapy may be useful for the prevention of complications in elderly ET patients.