Clinical characteristics and outcome in a large sample of MDS patients

Background: The myelodysplastic sydromes (MDS) are a heterogeneous group of hematopoietic disorders which have poor overall survival. As its incidence in the general population is only 4.6 out of 100,000, there is a paucity of epidemiological studies on the disorders.  We combined three data sets from Pennsylvania, Ohio and New York to study determinants of outcome.

Methods: De-identified patient and clinical data for 1192 incident cases of MDS from three sites were collected non-concurrently, from 1990-2010. All patients were followed from the date of diagnosis to transformation to Acute Myeloid Leukemia (AML), death, or end of the study period (2010). The median of the population baseline blood parameters was used to create cut offs for analyses for hemoglobin levels, neutrophil count, and platelet count. Clinical cutoff values were also utilized. Descriptive and survival analyses were performed.

Results:  The study population was 90.5% White, 60.6% male, and ever smokers in 57.8% of cases. Mean age at diagnosis was 68 years. Males were significantly more likely to be ever smokers than females (p<.0001); a significantly higher proportion of non-White patients was observed among males compared with females. Factors significantly associated with survival at multivariate analysis were being female [HR _adj: 0.79 (95% CI: 0.66-0.95)], and having a neutrophil count > 1.8 x 10⁹/L, the median value for this sample [HR _adj: 0.75 (0.6-0.93)].

Conclusions: Among MDS patients, females and patients with higher neutrophil counts have better survival than males or patients with lower neutrophil counts, respectively, and this may reflect differences in the biology of the disease, or in environmental exposure.