Persistently Higher Ratio of Gallbladder Cancer Incidence in Native American People than in Non-Hispanic Whites: Selected United States Regions, 1962-2021.

BACKGROUND: Gallbladder carcinoma (GbCa) is the most frequent malignancy of the biliary tract in the United States (U.S.), with American Indians and Alaska Native (AIAN) people showing much higher incidence rates than Non-Hispanic Whites (NHW). This disparity was first reported more than six decades ago, with the greatest disparity occurring in the Southwest U.S. and Alaska. However, few up-to-date studies show changes in the magnitude of this disparity. METHODS: We conducted a literature review of 455 publications (1929–2018) and performed a meta-analysis of the disparity across the U.S., Alaska, and Southwest U.S. (1962–2011). We also examined recent data from the Arizona Cancer Registry (1995–2021) and New Mexico Tumor Registry (1995–2020). We followed guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), employing Cochrane’s RevMan 5.3 software. RESULTS: Comparing GbCa incidence rates between AIANs and NHWs we found (1) all U.S. AIAN men and women had a 3.5- and 3-fold higher incidence rate, respectively. (2) Alaska and Southwest U.S. AIAN men and women had a 6- and 8.5-fold higher incidence rate, respectively. (3) Arizona AIAN men and women had an average 5.8- and 6.6-fold higher incidence rate, and New Mexico AIAN men and women had an average 6.1- and 6.0-fold higher incidence rate, respectively. CONCLUSION: AIANs, particularly in the Southwest U.S., persistently experience over 5-fold higher GbCa incidence rates than NHWs, evidenced by recent data from Arizona and New Mexico. The implications from our study include developing and disseminating educational materials that will benefit AIANs in high-disparity regions, understanding the disparity at the pathological and clinical management levels, and setting forth a focused implementation agenda to reduce the incidence and mortality of GbCa in high-risk populations.