Observations on the 2015 SEER Data
The latest annual federal data on mesothelioma diagnoses in the United States became available on April 15, 2015. The data reports on mesothelioma diagnoses during 2012, as determined from “cancer registries” from a sampling of some hospitals in the United States.
The data arises from the Surveillance, Epidemiology, and End Results (“SEER”) Program of the National Cancer Institute. The report is more technically described as the 1973-2012 SEER Research Incidence data (November 2014 submission). SEER collects data on cancer cases from various locations and sources throughout the United States. Data collection began in 1973 with a limited amount of registries and continues to expand to include even more areas and demographics today.
The data in 2012 reflect modest changes from 2011, but appear to support the trends previously identified in the data.
The SEER 9 database (the database with registry information collected since 1973) shows that the overall rate of mesothelioma diagnoses has been falling since the early 1990s. The rate trend differs, however, by sex. While the rate of male mesothelioma diagnoses has been falling since the early 1990s, the rate of female mesothelioma diagnoses appears to remain constant. See the figure below to review the trends.
The rates above are used to extrapolate from the sample to an estimate of the population of mesothelioma diagnoses. The SEER incidence data are represented below in the following chart:
Overall, the data indicate the estimated number of mesothelioma diagnoses is down from 3,229 in 2011 to 3,174 in 2012. Estimated male mesothelioma diagnoses is down from 2,488 in 2011 to 2,404 in 2012. Estimated female mesothelioma diagnoses increased from 741 in 2011 to 769 in 2012. The data does not distinguish between pleural and peritoneal mesothelioma diagnoses. The declining trend in rates noted above for overall and male diagnoses can be translated into potential declining incidence. However, the relatively constant rate of female mesothelioma diagnoses (combined with increasing population, longevity, etc.) appear to show increasing female incidence of mesothelioma diagnoses.
Over time, the scope of the SEER registries has expanded. Data from registries that expand SEER 9 were included in SEER 13 (SEER 9 plus Los Angeles and San Jose-Monterey, Rural Georgia, and the Alaska Native Tumor Registry), starting in 1992. In addition, there was further expansion starting in 2000 through SEER 18 (SEER 13 plus Greater California, Kentucky, Louisiana, New Jersey, and Greater Georgia). Greater California includes Central California, Sacramento, Tri-County, Desert Sierra, Northern California, San Diego/Imperial, and Orange County. Greater Georgia is represented by the entire state excluding: Clayton, Cobb, DeKalb, Fulton, Glascock, Greene, Gwinnett, Hancock, Jasper, Jefferson, Morgan, Putnam, Taliaferro, Warren and Washington Counties.
The SEER 9, SEER 13, and SEER 18 data show that the extrapolated estimates of the population of mesothelioma diagnoses does not wildly differ. The SEER incidence data are represented below in the following chart:
The figure shows that extrapolated estimates of the population of mesothelioma diagnoses from SEER 18 are generally greater than those from SEER 9. Conversely, estimates of the population of mesothelioma diagnoses from SEER 13 are generally less than those from SEER 9. Differences in the estimates can be attributed to the coastal representation of the registries (Stallard, Manton, & Cohen, 2004). Nevertheless, the patterns in the series (for years in common) appear similar. Given the shorter duration of the SEER 13 and SEER 18 data, the smoothed trend fit to the SEER 9 extrapolated estimates may not necessarily translate. Ignoring data prior to 1992 may suggest that mesothelioma diagnoses may be thought of as more or less “flat.”