BACKGROUND:The objective of this study was assess differences in the incidence, late-stage diagnosis, and prognosis of squamous cell carcinoma of the esophagus (SCCE), adenocarcinoma of the esophagus (AE), and adenocarcinoma of the gastric cardia (AGC) in metropolitan, urban, and rural areas in the United States. METHODS: The authors identified 29,527 patients with SCCE, AE, or AGC who were reported to the Surveillance, End Results Program between 2004 and2009. Incidence estimates for each malignancy were compared across metropolitan, urban, and rural areas. Multivariable logistic regression models were applied to evaluate the association between residential setting and late (distant-stage) diagnosis, and the results were reported as adjusted odds ratios and 95% confidence intervals (CIs). Cox proportional hazard models were used to examine the association between residential setting and cause-specific survival. RESULTS: When residential setting was analyzed using metropolitan population centers as the reference category, the incidence of AE was higher in urban areas (rate ratio [RR], 1.13; 95% CI, 1.06-1.20) and rural areas (RR, 1.15; 95% CI, 1.05-1.25), whereas the incidence of SCCE was lower in rural areas (RR, 0.80; 95% CI, 0.70-0.91). Rural patients were less likely to be diagnosed with stage IV AE compared with patients residing in metropolitan areas (odds ratio, 0.79; 95% CI, 0.65-0.97). No differences in prognosis were observed when patients from large metropolitan centers were compared with their rural counterparts. CONCLUSIONS: The current findings indicated that preconceptions regarding disparities in the time of diagnosis and survival between patients from metropolitan and rural areas in the United States are either unwarranted or out of date, at least with respect to gastroesophageal cancers. Cancer 2013;119:4020-7. V C 2013 American Cancer Society.KEYWORDS: disparities, gastroesophageal, rural, metropolitan, Surveillance, Epidemiology, and End Results Program.
INTRODUCTIONThree distinct clinicopathologic tumor types arise from the mucosal lining of the esophagus and proximal stomach. These include squamous cell cancer of the esophagus (SCCE), adenocarcinoma of the esophagus (AE), and adenocarcinoma of the gastric cardia (AGC). Although esophageal cancer is relatively uncommon in the United States, the incidence of esophageal and proximal gastric adenocarcinomas is rapidly increasing, whereas the incidence of SCCE is declining. 1 Etiologic factors associated with SCCE include alcohol consumption and smoking. 2-5 Risk factors for AE and AGC include gastric reflux, smoking, and obesity. [2][3][4][5] The prevalence of these risk factors differs across populations of rural, urban, and metropolitan areas of the United States. [6][7][8] The treatment of SCCE, AE, and AGC is complex and requires a multimodality approach, and the success of therapy may depend on the timeliness of diagnosis. 9,10 We hypothesize that, if individuals living in more remote areas have limited access to tertiary health care cent...