Hematological Responses to Megesterol Acetate in Patients with Myelodysplastic Syndrome Involving an Abnormal Chromosome 6.

The presence of an abnormal chromosome (chr) 6 often confers a poor prognosis on patients with myelodysplastic syndrome (MDS), particularly therapy related-MDS (t-MDS). We report two patients with MDS and an abnormal chr 6 who achieved significant improvements in their hematological parameters after being subjected to megesterol actetate at 80mg/d; one patient achieved a complete cytogenetic remission, albeit based on a limited study. The first patient, a 73 y female presented with a monocytopenia (thrombocytopenia; 43K/dl), a bone marrow consistent with MDS, blasts 6% and an abnormal chr 6 (sole cytogenetic abnormality) in February 2003. In July 2005 she was asymptomatic with a platelet count of 353K/dl and is due to have cytogenetics shortly. The second patient, a 72 y female presented in December 2004 with trilineage cytopenias, a bone marrow consistent with MDS and a complex karyotype, including an abnormal chr 2, 5, 6, 7 & 16. She had had a history of primary (essential) thrombocythemia of 25 y duration and had received P 32 and intermittent courses of hydroxyurea and was on hydroxyurea at the penultimate presentation and probably had t-MDS. This therapy was promptly discontinued and megesteral acetate commenced at 80mg/d. In July 2005 her hematological parameters had improved significantly (W 3.3K/dl; Hb 11.3g/dl;Platelets 135K/dl); her bone marrow remained hypercellular with reticulin fibrosis and cytogenetic studies revealed a 46XX kayotype in a limited sample. At the time of this report, both patients remain well on megesterol acetate with normal or near normal hematological parameters. MDS is a heterogeneous stem cell disorder and hematological and possible cytogenetic responses are noteworthy. The patient with the sole abnormal chr 6 has remained in hematological remission for over 18 months; the second patient with the complex karyotype is also, remarkably, maintaining near normal hematological parameters. We speculate that megesterol acetate, a relatively inexpensive progestational agent with a defined palce in the management of malignancy-related anorexia may have a role in selected patients with MDS. Updated observations and suggested hypotheses will be presented.