Secondary Myelodysplastic Syndrome.(sMDS) Presentation and Evolution.

The Secondary Myelodysplastic Syndrome (sMDS) represents a severe complication in the treatment of cancer. They are associated to the use of alkylating agents, radiation and immunosuppressive therapy. Their prognosis is unfavorable. Conventional chemotherapy is mainly palliative whereas allogenic bone marrow transplantation allows the cure of a small percentage of cases. Aims: To characterize and to describe the clinical presentation, therapeutic conduct and evolution in sMDS. This results where compared with those of primary MDS (pMDS) in patients enrolled into the observational study of Sociedad Argentina de Hematología from January 2007 to June 2009

There were analyzed 253 patients with diagnosis of MDS. sMDS correspond to 12.2 % (31/253)of the total, mean age 71 years old (r 23-84), relation M: F of 1:2.8 (being 1:2.2 in pMDS). Previous pathologies were: solid tumors in 17 patients (54%); 6 prostate Ca, 5 breast Ca, 4 GI Ca, 1 thyroid Ca, 1 bladder Ca, 1 pharynx Ca. Hematology malignancies were found in 7 patients: 2 Non Hodgkin Lymphoma, 2 Hodgkin Lymphoma, 1 Myeloma Multiple, 1 Chronic Myelomonocyticleukemia, 1p aplastic anemia. Six patients (23%) received immunosuppressive treatment for kidney transplantation, Wegener disease and glomerulonephritis. 85% of the patients received previous chemotherapy and/or radiotherapy. Result: There were analyzed 217 karyotypes (85.7%), 25 in the sMDS group and 189 in the pMDS, abnormal karyotypes in 14/25 (56%) vs 55/189 (29%) (p=0.006), complex karyotypes (unfavorable): 6/25 (24%) vs 8/189 (7%) (P=0.002). Twenty eight patients requiered treatment 28/31 (90.3%) vs 167/222 (75.2%) (p=0.09), transfusional therapy 23/31 (77.55%) vs 93/222 (42%) (p=0.001). Hypomethylating agents were used in 22,5% in sMDS vs 21,1% in pMDS and Erythropoyetin in 45,2% vs 48,6%. With a median follow up of 136 days (r:4-650), 8/31 progressed to AML (25.8%) vs 28/222 (13%) (p=0.005). Fourteen patients (45%) were death vs 47/222 (20.6%) (p=0.005); 17/31 (54.8%) of patients were alive in the sMDS group and 153/189 (80%) in the pSMD group (p= 0.005). Summary and

sMDS constituted 12.2% of the total of MDS that were reported. This entity has in our experience presence of unfavorable karyotype in more than the 50% of the cases, greater transfusion request, greater evolution to acute myeloid leukemia with high mortality and greater mortality than pMDS. This results confirm the bad prognosis of sMDS.

No relevant conflicts of interest to declare.