ASPO Abstracts
American Indians persistently experience much higher incidence rates of gallbladder cancer than Non-Hispanic Whites: a systematic review and meta-analysis
Category: Cancer Health Disparities
Conference Year: 2019
Abstract Body:
INTRODUCTION. Gallbladder carcinoma (GbCa), the most frequent malignancy of the biliary tract in the U.S., presents the greatest ethnic disparity in cancer incidence, with American Indians and Alaska Natives (AIAN) showing much higher rates than Non-Hispanic Whites (NHW). This disparity was first reported more than 55 years ago, with AIANs in Alaska and the Southwest U.S. experiencing the highest incidence rates. However, there is no up-to-date data showing any changes in the magnitude of this disparity. METHODS. We conducted a systematic review of 435 publications (1929-2018); performed a meta-analysis of the disparity across the U.S., Alaska, and Southwest U.S. (1962-2011); and zoomed in on Arizona (1995-2014). We followed guidelines set forth by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and employed Cochrane’s RevMan 5.3 software. Both random- and fixed-effect models were applied in the analyses. RESULTS. Our three key findings comparing GbCa incidence rates between AIANs and NHWs are as follows: (1) all U.S. AIAN men and women had a 3- and 4-fold higher incidence rate, respectively; (2) Alaska and Southwest U.S. AIAN men and women had a 6- and 8-fold higher incidence rate, respectively; and (3) in both 1995-2004 and 2005-2014, American Indian Arizonans had a 5- to 7-fold higher incidence rate in both men and women, with a noticeable decreasing trend in women. There was significant heterogeneity but no apparent publication bias was identified from all models of our meta-analysis. CONCLUSION AND IMPLICATIONS. AIANs, particularly in the Southwest U.S. and within Arizona, are persistently experiencing 5- to 8-fold higher GbCa incidence rates; this appalling ethnic disparity is observed in both women and men. The short-term actions based on our findings include developing and disseminating educational materials to the AIAN communities and Indian Health Services hospitals; understanding the ethnic disparity at the pathological and clinical management levels, which may lead to enhanced clinical outreach efforts; and setting forth a focused research agenda with the objectives to pinpoint the top risk factor(s) and to reduce the incidence and mortality of GbCa in the highest-risk AIAN populations.
Keywords: Gallbladder Cancer, American Indians and Alaska Natives, Non-Hispanic Whites, Incidence Rate, Ethnic Disparity