Gastric cancer among American Indians and Alaska Natives in the United States, 1999-2004.
BACKGROUND
Gastric cancer incidence rates for American Indians and Alaska Natives (AI/ANs) historically have exceeded those for non-Hispanic whites (NHWs). Previous reports may have underestimated the true burden of gastric cancer in AI/AN populations because of misclassification of AI/AN race in cancer registries.


METHODS
Population-based cancer registry data from 1999 through 2004 were used to describe gastric cancer incidence in AI/ANs and NHWs in the US. To address misclassification of race, registry data were linked with Indian Health Service administrative records, and analyses were restricted to residents of Contract Health Service Delivery Areas (CHSDA). Disease patterns were assessed for 6 geographic regions and for all regions combined. Rates were expressed per 100,000 population and were age-adjusted to the 2000 US standard population.


RESULTS
In CHSDA counties, gastric cancer incidence rates for AI/ANs were higher than the rates for NHWs across most regions. For both sexes combined, AI/AN rates ranged from 6.1 in the East region to 24.5 in Alaska; there was relatively little regional variation in NHW rates. Most patients with gastric cancer were diagnosed with late-stage disease, regardless of race, age, or sex. In some regions, cancer rates in the central/distal portions of the stomach were higher among AI/ANs than among NHWs, whereas rates in the proximal stomach were similar between the 2 populations.


CONCLUSIONS
AI/ANs are generally at greater risk for gastric cancer than NHWs. Relatively high rates of cancer in the central/distal portions of the stomach among AI/ANs in some geographic regions may indicate a disproportional burden of Helicobacter pylori-associated disease.
Wiggins
Charles L
CL
New Mexico Tumor Registry, University of New Mexico Cancer Center, Albuquerque, New Mexico 87131, USA. cwiggins@salud.unm.edu
Perdue
David G
DG
Henderson
Jeffrey A
JA
Bruce
Michael G
MG
Lanier
Anne P
AP
Kelley
Janet J
JJ
Seals
Brenda F
BF
Espey
David K
DK
D000230:Adenocarcinoma / Q000208:ethnology* / Q000473:pathology; D000328:Adult; D000368:Aged; D000413:Alaska / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007198:Indians, North American / Q000706:statistics & numerical data*; D004930:Inuit / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011159:Population Surveillance; D044469:Racial Groups / Q000706:statistics & numerical data; D012042:Registries; D013274:Stomach Neoplasms / Q000208:ethnology* / Q000473:pathology; D014481:United States / Q000453:epidemiology