PB2078 A RELATIVE ADVANTAGE OF STEM CELL TRANSPLANTATION (SCT) IN PATIENTS WITH LESS ADVANCED MYELODYSPLASTIC DSYNDROMES (MDS)

Background:An optimal treatment approach to patients with less advanced MDS is still a question of debate. We present results of a long term retrospecive study of outcome of MDS patients treated in a single center with different therapeutic modalities.Aims:A long term effect of different treatment approaches was evaluated in patients with RA or RARS subtype of MDS (according to the initial FAB classification) or with MDS‐SLD,MDS‐MLD,MDS‐RS or MDS with isolated del(5q) (according to WHO 2016 classification).MethodsThe data obtained from a long‐term follow up for a period of 30 years (1988‐2018) were analyzed in a group of 174 patients with primary myelodysplastic syndrome (MDS) and factors affecting prolonged survival were detected using different statistical methods including Kaplan Maier plots and multivariate analysis.Results:A median survival of untreated RA and RARS patients (43.5 and 48.3 months respectively) was significantly different from that in patients with advanced MDS (3.4 months) as well as estimated 3 years survival of 60.3% for RA vs. 58.3% for RARS vs. 0 months for advanced disease. An analysis of different treatment approaches revealed median survival of 43.8 months in 150 patients treated with best supportive care only (BSC) (median age 61.0 years) in comparison to 83.0 months in 53 transplanted patients (median age 40.0 years) (p < 0.01 for both age and survival). However, estimated 3 years survival was not statistically different between BSC and SCT treated patients (59.3 vs. 67.9%). A difference became significant after 5 years (43.3% for BSC vs. 54.7% for SCT and after 10 years of follow‐up (26% for BSC vs. 49.1% for SCT). The explanation of the differences may be a relatively high rate of transplantation related mortality (30.2%) on one hand and increasing rate of mortality after 5 years of follow‐up in BSC patients (20.7% vs. 3.8% in SCT patients) on the other hand. The reason of death after 5 years in BSC patients was mostly related to complications not directly connected with MDS, however, a late progression of the disease was observed in 9 BSC treated patients (63.5‐376.5 months after diagnosis of MDS). Two transplanted patients developed secondary malignancy 5 and 8 years after SCT. A significant difference in survival was observed between patients transplanted with < 5% bone marow blasts and those transplanted at the time of initial progression of the disease (111.5 months vs. 26.0 months, p = 0.001). A specific subgroups of patients responded to special treatment modalities. Estimated 5 years survial was 63.6% for patients with sEPO < 100 IU/l and < 2 TU of RBC/month treated with rHuEPO, 75.0% for patients with isolated del(5q) treated with lenalidomide and 83.3% for patients with hypoplastic MDS tretaed with ATG.Summary/Conclusion:The results of our retrospective analysis showed that younger patients with less advanced MDS without excess of blasts and adverse prognostic factors (profound cytopenia with transfusion dependency and signs of bone marrow failure, bone marrow fibrosis, adverse cytogenetics) should be transplanted as soon as possible after diagnosis before disease progression. A more conservative approach to patients with early disease who are not indicated for SCT was justified by a relatively high number of patients surviving 5 years with supportive care only.