Therapies for myelodysplastic syndromes (MDS) are initiated in patients with a shorter predicted survival or in patients with clinically significant cytopenias. The impact of most MDS therapies on survival remains unproven.
By Darci Picoult
It began with a bump. The size of a pinhead. Innocuous. An innocuous little pinhead of a bump on my vulva. Given that my gynecologist said the bump was probably nothing, I laughed it off. Which, in turn, made my bump mad. Very mad. It wanted my attention. And so it grew. I smeared it in medicine. It grew more. More medicine. More growth. Hanukkah came. Then Christmas. A war raged between us. I went to battle in the middle of the night with salt baths and creams. Prayed for its departure...
The mainstay of treatment for MDS has traditionally been supportive care, particularly for those patients with symptomatic cytopenias or who are at high risk of infection or bleeding.[1,2] Transfusions are reserved for the treatment of active bleeding; many centers offer prophylactic platelet transfusions for patients with platelet counts lower than 10,000/mm3. Anemia should be treated with red-cell transfusions to avoid symptoms. (Refer to the PDQ summary on Fatigue for more information on anemia.)
No prospective trials have demonstrated the benefit of prophylactic use of myeloid growth factors in asymptomatic neutropenic MDS patients. Similarly, the use of prophylactic antibiotics in such patients is of uncertain benefit. While appropriate use of antibiotics in febrile patients is standard clinical practice, the benefit of myeloid growth factors in such settings is unknown.
The use of erythropoiesis-stimulating agents (ESAs) may improve anemia. The likelihood of response to exogenous erythropoietin administration is dependent on the pretreatment serum erythropoietin level and on baseline transfusion needs.
In a meta-analysis summarizing the data on erythropoietin in 205 patients with MDS from 17 studies, responses were most likely in patients who were anemic but who did not yet require a transfusion, patients who did not have ring sideroblasts, and patients who had a serum erythropoietin level lower than 200 u/L. Effective treatment requires substantially higher doses of erythropoietin than are used for other indications; the minimum effective dose studied is 60,000 IU per week. The use of high-dose darbepoetin (300 µg/dose weekly or 500 µg/dose every 2–3 weeks) has been reported to produce a major erythroid response rate of almost 50% in patients whose endogenous erythropoietin level was lower than 500 µ/mL.[5,6] Most studies discontinued ESAs in patients who failed to show hematologic improvement after 3 to 4 months of therapy. Average response duration is approximately 2 years.