The Impact of Different TP53 Mutations on Outcome in Patients with Myelodysplastic Syndromes (MDS)

outcomes among elderly Medicare-enrolled MDS patients in the USA. Methods: Patients were identified from the SEER-Medicare database using these criteria: 1) ICD-O-3 codes for MDS, 2) diagnosed between 1/1/2005 and 12/31/2011, 3) aged 66 years at diagnosis, and 4) enrolled in Medicare Parts A and B continuously through death or end of study (12/31/2012). Medicare payments were used to estimate costs and adjusted to 2012 US dollars. Cumulative costs were calculated as per Zhao et al (Stat Med 2007). To estimate MDS-specific costs, costs in a matched group of cancerfree Medicare beneficiaries were subtracted from costs in MDS cohort. Comorbidities were used to calculate a modified Elixhauser comorbidity and the disability status scores. KaplaneMeier estimates described overall survival (OS) probabilities from date of diagnosis. Hazard ratios (HR) were estimated using multivariate Cox proportional hazard models. Tests were two-sided with an alpha of 0.05. Results: Out of 8,564 eligible patients, 86.7% were white, 53.0% males, 52.5% 80 years at diagnosis, and 15.7% received hypomethylating agents ([HMA]. Twoand 3-year observed OS rates were 48.7% and 40.6%, respectively. The 2-year MDS-specific cost per patient ranged between $43,950 and $83,961 across 12 states. Factors associated with improved 2-year survival included female gender, non-white ethnicity, younger age at diagnosis, refractory anemia (RA) and RA with ring sideroblasts subtypes, pre-diagnosis health costs, lower Elixhauser comorbidity and lower disability status scores. In contrast, zip code-median household income level, HMA use, and the two-year state-level MDS-specific costs [Reference: low costs, HR for medium costs 1.02, 95%CI, 0.93-1.12, P-value1⁄40.74, and for high costs HR was 0.99, 95%CI, 0.92-1.06, P-value1⁄40.73] were not associated with the 2-year OS probabilities. Additionally, the 2-year MDS-specific costs were also not associated with the 3-year OS probabilities. Conclusions:Medicare expenditure on elderly MDS patients varied significantly across different states in the USA during the two years post-diagnosis, but was not related to the 2-year or 3-year survival. The disconnection between cost and outcome warrants additional research.