GASTROINTESTINAL CANCER INCIDENCE AND TRENDS IN UNITED STATES RURAL AND URBAN POPULATIONS
Skyler Taylor1,2, Amir A. Khan*1, Whitney Zahnd2,3, Sabha Ganai1,2
1Department of Surgery, Southern Illinois University, Springfield, IL; 2Population Science and Policy, Southern Illinois University, Springfield, IL; 3University of South Carolina Arnold School of Public Health, Columbia, SC
Background: While a decline has been noted in the incidence of certain gastrointestinal (GI) cancers, a possible consequence of improvements in dietary risk factors and opportunities for endoscopic screening, limited research has been conducted on rural and urban disparities in overall gastrointestinal cancer incidence and trends. We hypothesized that rural-urban disparities exist in development of cancers of the GI tract.
Methods: A population-based observational cohort study was conducted using the Surveillance, Epidemiology, and End Results (SEER) database. We calculated age-adjusted incidence rates, rate ratios (RR), and annual percentage change (APC) for alimentary canal cancers, hepatopancreatobiliary (HPB) cancers, and gasteroenteropancreatic neuroendocrine tumors (GEP-NETs) of the GI tract. We compared rural and urban populations, examining incidence rates from 2010 to 2014, and analyzing trends from 2000 to 2014.
Results: Incidence rates of alimentary tract cancers in rural populations were greater than the urban population (RR 1.13; 95% CI, 1.11-1.14) in all anatomical regions with the exception of gastric cancer, and have declined more rapidly in urban (APC -2.5; 95% CI, -2.6 to -2.4) compared to rural populations (APC -1.8; 95% CI, -2.2 to -1.5). HPB cancer incidence was less in rural compared to urban populations (RR 0.85; 95% CI, 0.83 -0.87) for all sites. Incidence trends for HPB cancers showed a greater increase for rural (APC 3.1; 95% CI, 2.7-3.5) than urban populations (APC 2.5; 95% CI, 2.2 -2.7). While GEP-NETs have been increasing in rural (APC 4.7; 95% CI, 3.6 - 5.8) and urban (APC 4.1; 95% CI, 3.6 - 4.6) populations, there is no difference in incidence (RR 1.02; 95% CI, 0.97-1.07) by locale.
Conclusions: There has been an unequal change in incidence of some GI cancers in rural and urban populations. Rural populations had a greater incidence of cancers of the esophagus, colon, rectum, and NETs of the midgut. Urban populations had a greater incidence of cancers of the stomach, HPB sites, and NETs of the hindgut and pancreas. Disparities may exist due to differences socioeconomic factors, race, education, access to care, and viral prevalence. A persistent increase in pancreatic cancer incidence in both rural and urban populations warrants further exploration.
Age-adjusted incidence rates and rate ratios for gastrointestinal cancers in rural and urban areas, 2010-2014.
| Urban Incidence (per 100,000) | Rural Incidence (per 100,000) | Rate ratio (95% CI) | p-value | ||
| ALIMENTARY TRACT | 33 | 37.2 | 1.13 (1.11 - 1.14) | <0.0001 | |
| Esophageal | All | 3.4 | 4.0 | 1.17 (1.12 - 1.23) | <0.0001 |
| Adenocarcinoma | 2.2 | 2.7 | 1.23 (1.16 - 1.30) | <0.0001 | |
| Squamous | 1.2 | 1.2 | 1.05 (0.97 - 1.14) | 0.22 | |
| Gastric | 3.4 | 3.0 | 0.88 (0.83 - 0.93) | <0.0001 | |
| Small Intestine | 0.5 | 0.5 | 0.94 (0.82 - 1.07) | 0.36 | |
| Colon | 24.4 | 28.5 | 1.16 (1.14 - 1.18) | <0.0001 | |
| Rectum | 5.1 | 6.2 | 1.23 (1.18 - 1.28) | <0.0001 | |
| Anal and anal canal | All | 1.2 | 1.3 | 1.01 (0.93 - 1.10) | 0.78 |
| Adenocarcinoma | 0.1 | 0.1 | 0.97 (0.73 - 1.27) | 0.90 | |
| Squamous | 1.1 | 1.1 | 1.02 (0.93 - 1.11) | 0.71 | |
| HEPATOPANCREATICOBILIARY | 19.4 | 16.4 | 0.85 (0.83 - 0.87) | <0.0001 | |
| Liver (HCC) | 6.8 | 5.1 | 0.75 (0.72 - 0.78) | <0.0001 | |
| Gallbladder | 0.8 | 0.7 | 0.85 (0.76 - 0.94) | 0.004 | |
| Cholangiocarcinoma | Intrahepatic | 0.8 | 0.7 | 0.89 (0.79 - 0.99) | 0.03 |
| Extrahepatic | 0.5 | 0.4 | 0.74 (0.63 - 0.86) | <0.0001 | |
| Exocrine Pancreas | 10.4 | 9.5 | 0.92 (0.89 - 0.94) | <0.0001 | |
| GASTROENTEROPANCREATIC NEUROENDOCRINE TUMORS (GEP-NETs) | 3.8 | 3.9 | 1.02 (0.97 - 1.07) | 0.44 | |
| Foregut NETs | 0.5 | 0.5 | 1.07 (0.94 - 1.23) | 0.29 | |
| Midgut NETs | 1.7 | 1.9 | 1.15 (1.07 - 1.23) | 0.0001 | |
| Hindgut NETs | 1.3 | 1.2 | 0.89 (0.81 - 0.97) | 0.007 | |
| Endocrine Pancreas / PNETs | 0.3 | 0.2 | 0.80 (0.66 - 0.97) | 0.02 | |
Back to 2019 Abstracts
