Temporal Changes in Esophageal Cancer Mortality by Geographic Region: A Population-based Analysis

Purpose To analyze differences in esophageal cancer survival by geographic region of the U.S. from the 1970s to the 2000s, and attribute the causes of these discrepancies. Methods Raw data were obtained from the Surveillance Epidemiology and End Results (SEER) program of the National Cancer Institute. Patients were stratified by decade of diagnosis and by geographic region (East, Hawaii/Alaska, Midwest, Southwest, and West), containing SEER registries. The Kaplan-Meier method with the log-rank test was used to compare the overall survival (OS) among these geographic groups. A multivariate Cox Proportional Hazard analysis was conducted to evaluate the impact of the following factors on differences in survival: patient age, gender, race, tumor stage, site, histology, treatment method, and metropolitan size. Results A total of 87,834 patients were identified. OS has increased significantly since 1973, with five-year OS improving from 4.9% (the 1970s) to 15.3% (2000s) (P<0.001). Residence in the East was prognostic for higher OS compared to all the other regions, with a median OS of six months in the 1970s and 12 months in the 2000s (P<0.001). The multivariate analysis revealed increased age, African American race, distant disease, non-distal tumor location, squamous cell histology, and no radiation therapy were associated with worse OS. The West and East had the highest amount of cancer centers (12 and seven, respectively). And the East had the highest number of cancer centers per person (5.7E-07) while the South had the lowest (1.6E-07). Conclusions There are disparities in esophageal cancer survival and quality of care through different geographic regions of the U.S., which may be attributed to a combination of the unbalanced distribution of medical resources, the regional differences in cancer biology, and other lifestyle and socioeconomic factors. More research should be conducted to further characterize regional differences and guide the implementation of improvements in survival.