Abstract SY14-04: Cancer health disparities in American Indian and Alaskan Native populations
Authors: Willman Cheryl L. 
Published: July 2017

American Indian and Alaska Native communities constitute 562 federally recognized independent sovereign nations within the United States, including 229 located in Alaska and the remainder in 33 other states. These tribal nations and communities are highly diverse in ethnicity, language, customs, modes of tribal governance, and cultural perspectives and beliefs, particularly regarding cancer etiology and the conduct of research and healthcare or community interventions. These nations have very significant cancer health disparities, disproportionately low rates of cancer screening, and more limited access to state of the art cancer diagnosis and treatment and cancer clinical trials when compared to other Americans. Cancer incidence and mortality rates vary, often dramatically, among different tribal nations in different geographic regions of the U.S. (see American Indian and Alaska Native Cancer Profiles at surveillance.cancer.gov and http://statecancerprofiles.cancer.gov). These variations may result from differing cancer etiologies, environmental exposures, social behaviors (including diet and tobacco use), spectra of cancer-associated somatic mutations and genetic susceptibilities to cancer and pre-cancerous conditions (such as diabetes), limited rates of community-based cancer screening, and limited access to health care. American Indian and Alaska Natives are often diagnosed at later stages of disease and have a poorer prognosis for several types of cancer when compared to other racial/ethnic groups. Regional variations in cancer staging and survival within specific cancers are also observed. Highlighting specific examples of cancer health disparities, lung cancer incidence rates for American Indians and Alaska Natives in the Northern Plains and Alaska are currently among the highest in the world. In contrast, lung cancer rates in American Indians in the Southwestern U.S. are among the lowest in the country. Kidney and hepatobiliary cancers are increasing in incidence in many tribal communities and occur at a significantly higher frequency than observed in other racial and ethnic groups. American Indians and Hispanics, particularly in the Southwest, have the nation’s highest rates of hepatocellular carcinoma, gall bladder cancer, and cholangiocarcinoma. Colorectal cancers are also seen at higher rates in American Indian and Alaska Native communities, which may be a result of exceedingly low rates of colorectal cancer screening. Tribal women and girls are also disproportionately impacted by higher rates of cervical cancer, despite implementation of more robust cervical cancer screening programs. Hispanic and American Indian children and adolescents affected by acute lymphoblastic leukemia (ALL) also have significantly poorer outcomes than other racial and ethnic groups in the U.S. Strikingly, Hispanic children now have the highest ALL incidence in the United States, increasing from 8% of all pediatric ALL cases reported in 1990 to nearly 25% in 2005. Our genomic studies, supported by the NCI TARGET / TCGA (ocg.cancer.gov) programs, discovered that American Indian children affected by ALL, and Hispanics with a significant degree of American Indian genetic ancestry, have a high frequency of unique leukemia-causing mutations compared to other racial/ethnic groups (such as those in CRLF2/JAK signaling pathways or novel fusions involving genes encoding tyrosine kinases or genes regulating tyrosine kinase signaling pathways) and a higher frequency of unique ALL risk alleles (including those in GATA3). These mutations can be targeted with tyrosine kinase inhibitors (TKIs) or novel therapeutic strategies that are now being tested in national clinical trials, focused on improving overall outcomes in these diseases.

In recognition and respect of the sovereign nation status of American Indian and Alaska Native communities, of tribal laws, of requirements for tribal membership, and of unique cultural perspectives and beliefs, meeting and overcoming cancer care delivery challenges and significant cancer health disparities through research and engagement requires unique, sustained, collaborative, community-engaging, partnership models. Such partnerships must address the concerns of American Indian and Alaska native communities regarding research and health care intervention, including joint oversight of collaborative projects; regular communication of data and results; genetic privacy; appropriate and potentially more limited informed consent for specific studies; appropriate oversight of biospecimen acquisition and utilization of samples collected and stored for specific research projects; intellectual property; and access to data and modes of data sharing and utilization. The National Cancer Institute, The Centers for Disease Control, and the Indian Health Service have supported several projects within tribal communities, largely focused on cancer control. Such activities include the provision of educational materials (such as Native Circle) to communities, the development of high quality cancer registries for American Indians and Alaska Natives including 12 Tribal Epidemiology Centers (tribalepicenters.org), and training and education programs targeted to American Indian and Alaska Native students. The NCI SEER/New Mexico Tumor Registry at the University of New Mexico Comprehensive Cancer Center, which holds cancer registry data from American Indian communities in New Mexico and Arizona and supports the Cherokee Native Cancer Registry and the Alaska Native Tumor Registry, is working with the NCI to develop an integrated Native American Cancer Registry to facilitate the rigor of data collection to allow American Indian and Alaska Native communities to track their cancer data and monitor the incidence and outcome of cancers in their communities. New collaborative partnership models (such as The Southcentral Foundation of Alaska, the TGEN/Pima Indian Nation Partnership in Arizona, and evolving partnerships in New Mexico, Utah, and other regions of the U.S.) with full engagement of tribal nations and collaborating universities, research entities, and health systems are providing new opportunities for American Indian and Alaska Native communities to engage in and benefit from cancer research focused on gene-environment interactions and cancer causation, cancer precision medicine and discovery of the spectrum of cancer-associated mutations in cancers disproportionately affecting these communities, cancer education and screening interventions, and cancer clinical trials.

Citation Format: Cheryl L. Willman. Cancer health disparities in American Indian and Alaskan Native populations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr SY14-04. doi:10.1158/1538-7445.AM2017-SY14-04