Recent improvement in completeness of incidence data on acute myeloid leukemia in US cancer registries.

A limitation of data prior to 2010 on incidence of leukemia in US population-based cancer registries is that acute myeloid leukemia (AML) diagnosed as progression (transformation) from a previously diagnosed myelodysplastic syndrome (MDS), myeloproliferative neoplasm (MPN, other than polycythemia vera), or chronic myeloid leukemia (CML) was not reportable. Data were used from a research database for the 18 cancer registries of the Surveillance, Epidemiology and End Results (SEER) Program, and from all registries in the US Cancer Statistics (USCS) database. Analyses compared the age-standardized incidence rate (ASIR) per 100,000 for AML before (ie, 2000-2009) vs after (ie, 2010) the new reportability rules for AML. The ASIR for all ages combined fluctuated until increasing from 3.60 (95 percent CI, 3.47-3.73; N = 3,068) in 2009 to 3.89 (95 percent CI, 3.76-4.03; N = 3,355) in 2010 in SEER, and from 3.64 (95 percent CI, 3.58-3.71; N = 11,488) in 2009 to 3.89 (95 percent CI, 3.82-3.96; N = 12,351) in 2010 in USCS. The increase from 2009 to 2010 was limited to ages 60+ years (from 13.87 to 15.59 in SEER and from 14.13 to 15.34 in USCS). The SEER research database allowed analysis by the number of cancers per person, which showed that the increase in AML cases and rates for age 60+ years from 2009 to 2010 was due to an increase in cases with a previous cancer(s) largely representing newly-reportable post-MDS, post-MPN and post-CML AML cases. Continued surveillance is needed to address the eventual impact of delayed reporting of diagnoses in 2010 on estimates and projections of AML incidence in the US population.