Myelodysplastic syndromes (MDS) occur mainly in older persons, and these patients are likely to have comorbidities. We studied the impact of comorbidities on non-leukemic death (NLD) and overall survival (OS) in MDS patients with the aim of developing a specific prognostic index. Eight hundred forty consecutive patients receiving a diagnosis of MDS at Policlinico San Matteo, Pavia, Italy, between 1992 and 2006 were retrospectively evaluated. One or more comorbidities were present in 455/840 (54%) patients: the older the age, the higher their prevalence (P<0.001). Cardiac disease was observed in 25% of patients, liver disease in 16%, diabetes in 11%, prior solid tumor in 10%, nephropathy and pulmonary disease in 4%. Non-leukemic causes of death included cardiac failure (63%), infection (24%) and hemorrhage (7%). In a Cox analysis with age, sex, WHO category, cytogenetics and transfusion-dependency as time-dependent covariates, the presence of one or more comorbidities significantly affected both the risk of NLD (HR=1.91, P=0.001) and OS (HR=1.51, P=0.01), while it did not influence the risk of leukemic progression. The negative effect of comorbidities on OS was more evident in patients without excess of blasts (HR=1.8 P=0.007), while it retained a borderline significance in patients with more advanced disease (P=0.05). By including comorbidities as distinct entities in multivariable analysis, cardiac failure, liver or pulmonary disease, and solid tumors were found to independently affect the risk of NLD (HR=3.7, HR=2.08, HR=2.07 HR=2.23, respectively; P values from <0.001 to 0.033). Based on results of uni- and multivariable analysis, we developed a prognostic model for predicting the effect of comorbidities on NLD and OS. For each comorbidity, risk scores were estimated from the coefficients of the Cox regression. This MDS-specific comorbidity index (MDS-CI) allowed us to identify 3 groups of patients with different probability of NLD and OS (HR 2.78, P<0.001; HR 1.67 P=0.001), and provided a better stratification than the available non MDS-specific indices. Focusing on WPSS categories [
Disclosure: No relevant conflicts of interest to declare.