LAUSR

1573Background: There are no epidemiologic studies of SWM due to lack ofICD codes specific for smoldering status. Methods: The NCDB represents ~70% of cancer cases in the US. It records the time to initial treatment or reasons for not receiving treatment. Using the 2004-2012 database, we estimated the overall proportion of new adult WM cases that are smoldering and analyzed outcomes according to socio-geo-demographic subgroups. Patients who were recommended treatment (irrespective of administration status) or died within 120 days of diagnosis were considered to have active WM while those who did not require treatment and had follow-up ≥120 days after diagnosis were considered to have SWM. Results: 2322 (28%) of 8302 patients diagnosed with WM were SWM. Median age at diagnosis was 71 (range 28-90) years. Median age did not change significantly during 2004-2012 (P = 0.83) but the proportion of smoldering disease decreased with time (P = 0.02). The proportions of SWM according to socio-geo-demographic subgro...