Epidemiology of myelodysplastic syndromes and chronic myeloproliferative disorders in the United States, 2001-2004, using data from the NAACCR and SEER programs.

Reporting of myelodysplastic syndromes (MDSs) and chronic myeloproliferative disorders (CMDs) to population-based cancer registries in the United States was initiated in 2001. In this first analysis of data from the North American Association of Central Cancer Registries (NAACCR), encompassing 82% of the US population, we evaluated trends in MDS and CMD incidence, estimated case numbers for the entire United States, and assessed trends in diagnostic recognition and reporting. Based on more than 40 000 observations, average annual age-adjusted incidence rates of MDS and CMD for 2001 through 2003 were 3.3 and 2.1 per 100,000, respectively. Incidence rates increased with age for both MDS and CMD (P < .05) and were highest among whites and non-Hispanics. Based on follow-up data through 2004 from the Surveillance, Epidemiology, and End Results (SEER) Program, overall relative 3-year survival rates for MDS and CMD were 45% and 80%, respectively, with males experiencing poorer survival than females. Applying the observed age-specific incidence rates to US Census population estimates, approximately 9700 patients with MDS and 6300 patients with CMD were estimated for the entire United States in 2004. MDS incidence rates significantly increased with calendar year in 2001 through 2004, and only 4% of patients were reported to registries by physicians' offices. Thus, MDS disease burden in the United States may be underestimated.