Excess Mortality in Low-Risk MDS Can be Explained By MDS and AML Related Causes of Death

Abstract Background Data on causes of death (COD) in patients with lower-risk (LR-MDS) is limited and sometimes conflicting. In contrast to higher-risk MDS, many LR-MDS patients die from conditions associated with advanced age, not directly associated with the underlying disease. Infections and cardiovascular disorders (CVD) have been reported as frequent COD in LR-MDS, but whether the incidence is higher than in age-matched population, is not known. The EUMDS Registry has been collecting prospective observational data on LR-MDS since 2008. The comprehensive clinical and laboratory data provides a unique chance to assess the impact of LR-MDS on survival either by causes related to MDS or indirectly related to MDS by aggravation of co-morbidities. Objectives To assess the impact of MDS and associated co-morbidities on COD in patients with LR-MDS and to evaluate the COD in the whole group and across participating countries. Methods: We evaluated clinical and laboratory data of LR-MDS patients registered in EUMDS registry from 2008 to 2018. Data were obtained by 145 centers from 16 European countries and Israel. MDS related causes of death were defined as infection, bleeding, MDS progression and AML transformation. Overall survival(OS) and relative survival(RS) were estimated using the Stata program 'strel' with age, sex and country specific background obtained from national life tables for the CONCORD program. RS is a standard approach used to take into account competing causes of death by adjusting for the age and sex specific mortality in the general population, estimating the excess mortality in these patients compared to that seen in the general population of each country. Results Overall data on 2235 LR-MDS patients was available in the EUMDS registry. Of these, 822 (36,7%) patients had died at the time of analysis. Median age was 77 years and 65% of the patients were male. Nearly half of them (46.9%) were diagnosed as IPPS low risk. The MDS-Comorbidity Index was low, intermediate and high in 55.7%, 37.5% and 6.8% of patients respectively. The most common COD were those considered as related to MDS 41.7% (Table 1). Deaths due to cardiovascular and pulmonary diseases were reported in 10.1% and 4.9% respectively. Other reasons (e.g. liver, renal failure, second malignancy) were found in 18.2%. In 25% of patients, the precise reason of death remained unknown. The proportion of MDS related COD were different between participating countries with lower rates in Germany (30%), France (31.3%) and higher in Portugal (55%), Greece (55.2%) and Romania (63.1%). Median follow-up was 2.1 years (0.1-10 years). Five-year overall survival in the whole cohort was 47.1% (95% CI: 44.1%-49.9%) and 5-year relative survival (attributed to MDS/AML only) was 59.1% (95% CI:55.4%-62.5%)(Figure 1). One year overall and relative survival was 90.4% (95% CI:89.1%-91.6%) and 94.4% (95% CI:93%-95.5%) respectively. Conclusions: MDS- related complications are the most common causes of death in LR-MDS patients. Comparison of overall and relative survival supports that observation and indicates that excess mortality in LR-MDS patients can be mainly explained by MDS/AML related causes. Interestingly, the strongest influence of MDS/AML attributable deaths was observed during the first year from diagnosis. Disclosures Fenaux: Janssen: Honoraria, Research Funding; Jazz: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Roche: Honoraria; Otsuka: Honoraria, Research Funding. Stauder:Teva: Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Germing:Novartis: Honoraria, Research Funding; Janssen: Honoraria; Celgene: Honoraria, Research Funding. de Witte:Novartis: Research Funding; Celgene: Honoraria, Research Funding; Amgen: Consultancy, Research Funding. Smith:Jazz Pharmaceuticals: Research Funding; Johnson & Johnson: Research Funding; Gilead Sciences: Consultancy; Novartis: Research Funding.