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Introduction Data on cigarette smoking prevalence among Alaska Native and American Indian (ANAI) people are limited to cross-sectional studies or specific subpopulations. Using data from the Alaska Education and Research toward Health (EARTH) Study 10-year follow-up, this study assessed patterns of smoking from baseline and factors associated with current use. Aims and Methods EARTH Study urban south central ANAI participants (N = 376; 73% women) provided questionnaire data on smoking at baseline and 10-year follow-up. Multivariable-adjusted logistic regression assessed whether gender, cultural factors (Tribal identity, language spoken in the home), depressive symptoms (PHQ-9), baseline smoking status, and baseline cigarettes per day (CPD) were associated with current smoking at follow-up. Results Current smoking was 27% and 23% at baseline and follow-up, respectively. Of baseline smokers, 60% reported smoking at follow-up (77% men, 52% women). From multivariable-adjusted analyses, the odds of current smoking at follow-up were lower among women than men, those who never or formerly smoked versus currently smoked at baseline, and smoking Conclusions Our project is among the first to longitudinally explore smoking within an ANAI cohort. While we observed persistent smoking during a 10-year period, there were important differences by gender and CPD in quitting. These differences may be important to enhance the reach and efficacy of cessation interventions for ANAI people. Implications This study contributes novel longitudinal information on cigarette smoking prevalence during a 10-year period among Alaska Native and American Indian (ANAI) people. Prior data on smoking prevalence among ANAI people are limited to cross-sectional studies or specific subpopulations. Our project is among the first to longitudinally explore smoking prevalence within an ANAI cohort. We observed persistent smoking during a 10-year period. The study also contributes information on differences by gender and cigarettes smoked per day in quitting. These findings have implications for enhancing the reach and efficacy of cessation interventions for ANAI people.

Background: Stomach cancer incidence and mortality rates are declining across circumpolar nations, but the burden may not be distributed equally across subpopulations, including Indigenous peoples. Our objective was to examine stomach cancer incidence and mortality trends across circumpolar populations. Methods: Cancer incidence and mortality data from 1999–2016 were obtained from the Canadian Cancer Registry, Canadian Vital Statistics, CDC WONDER, NORDCAN, Northwestern Russian cancer registries, and National Cancer Reports. The direct method was used to calculate 10-year rolling age-standardized incidence and mortality rates to the world (WHO 2000–2025) and 2011 Canadian standard populations. Standardized incidence rate ratios (SRR) were calculated. Data were stratified by sex, year, and region. U.S. data were broken down by race [White; American Indian/Alaska Native (AIAN)]. Race data were not available from non-U.S. cancer registries. Results: Most populations showed declining incidence and mortality rates over time. Incidence rates among Greenland males and females, Alaska AIAN males and females, and Northern Canadian both sexes were elevated compared with regional counterparts and remained stable. The largest male SRR was observed among Alaska AIAN versus Alaska Whites [SRR = 3.82; 95% confidence interval (95% CI), 2.71–5.37]. The largest female SRR was observed among Alaska AIAN versus Alaska Whites (SRR = 4.10; 95% CI, 2.62–6.43). Conclusions: Despite stomach cancer incidence and mortality rates declining overall, some northern and Indigenous populations experience elevated and stable incidence and mortality rates. Impact: There is a need to address disparities observed among circumpolar subpopulations. Given similarities in incidence, mortality, and risk factor prevalence across circumpolar regions, addressing disparities could benefit from coordinated international action.

Alaska Native (AN) people have among the highest rates of colorectal cancer (CRC) recorded globally. Preventing CRC is an important health priority of AN tribal health leaders and communities. Lifestyle and genetic risk and protective factors for CRC among AN people remain understudied. We have been working to establish a tribally led, community-based, comprehensive investigation of lifestyle and genetic risk and protective factors for CRC among AN people. We describe the process of initiating this research study, including conversations with key tribal health system staff. We discuss themes that arose during these conversations and literature review and describe how those themes were used during the study design and protocol development phase. This description is intended to provide guidance to other researchers working to establish community-based studies of cancer risk, particularly among tribal communities.

PURPOSE: Cancer is the leading cause of mortality among Alaska Native (AN) people. The Alaska Education and Research Towards Health (EARTH) cohort was established to examine risk and protective factors for chronic diseases, including cancer, among AN people. Here, we describe the cancer experience of the Alaska EARTH cohort in relation to statewide- and region-specific tumor registry data, and assess associations with key cancer risk factors. METHODS: AN participants were recruited into the Alaska EARTH cohort during 2004–2006. Data collected included patient demographic, anthropometric, medical and family history, and lifestyle information. This study linked the Alaska EARTH data with cancer diagnoses recorded by the Alaska Native Tumor Registry (ANTR) through 12/31/15. We compared EARTH incidence to ANTR statewide incidence. We examined independent associations of smoking status, diet, BMI, and physical activity with incident all-site cancers using multivariable-adjusted Cox proportional hazards models. RESULTS: Between study enrollment and 2015, 171 of 3,712 (4.7%) Alaska EARTH study participants were diagnosed with cancer. The leading cancers among Alaska EARTH participants were female breast, lung, and colorectal cancer, which reflected those observed among AN people statewide. Incidence (95% CI) of cancer (all sites) among Alaska EARTH participants was 629.7 (510.9–748.6) per 100,000 person-years; this was comparable to statewide rates [680.5 (660.0–701.5) per 100,000 population]. We observed lower risk of all-sites cancer incidence among never smokers. CONCLUSIONS: Cancer incidence in the Alaska EARTH cohort was similar to incidence observed statewide. Risk and protective factors for leading cancers among AN people mirror those observed among other populations.

INTRODUCTION Alaska Native (AN) people experience a high burden of gastric cancer compared with other US Native and non-Native populations. Previous reports have suggested that gastric cancer in AN people occurs at a younger age and is a more aggressive pathologic type. We evaluated all cases of gastric cancer in AN people from 1990 to 2017 and compared the epidemiologic and pathologic characteristics with the gastric cancers that occurred in the same time in the US white (USW) population. METHODS Cancer data were collected by the Alaska Native Tumor Registry and National Cancer Institute's Surveillance, Epidemiology, and End Results Program. Comparisons were performed looking at the age and sex distribution of the affected AN and USW people, as well as the cancer characteristics, including the location, stage, and pathology. RESULTS The age distribution was significantly different between AN and USW patients (P < 0.001), with a greater proportion of AN people diagnosed younger than 40 years (11% vs 3%, P < 0.0001) and 40-59 years (37% vs 20%, P < 0.0001). In addition, a greater proportion of AN people were diagnosed with distant stage cancer (AN: 48% and USW: 35%, P < 0.0001). The age-adjusted rate of gastric cancer in the AN population was significantly higher than the USW population (20.8 vs 6.7 per 100,000 persons, P < 0.0001). Although there has been a significant decrease in the gastric cancer incidence rate in the USW population, no significant change in incidence was seen in the AN population. DISCUSSION This study highlights the disproportionate burden of gastric cancer in the AN population. Further work is needed to address and understand this disparity.

Background Alaska Native (AN) people have the highest rates of colorectal cancer (CRC) globally. Increasing CRC screening has been effective in reducing CRC-related morbidity and mortality in other populations. Objective To examine recent descriptive epidemiology and longer-term CRC trends among AN people. To determine any changes in the descriptive epidemiology of CRC among AN people concurrent with increases in screening prevalence. Methods: We estimated age-specific CRC incidence and mortality rates 2000−2017. To examine longer-term trends in incidence and mortality 1990–2017, we conducted Joinpoint regression analyses of three-year rolling average incidence and mortality rates. We calculated descriptive statistics for two time-periods: 2000−2008, and 2009−2017. Finally, we examined five-year survival probability. Results CRC incidence increased over time (1990–2017) among AN people aged less than 50 years, while there were modest declines in AN people older than 50 years old since 2000. Overall, AN CRC mortality rates declined between 1990 and 2004, but have been increasing steadily since that time. Comparing 2000−2008 with 2009−2017 we observed no difference in CRC incidence and mortality, age at diagnosis, tumor size, tumor location, or stage distribution. Survival analyses indicated no change in hazard of death between 2004−2008 and 2009−2017 (HR 1.02, 95 % CI: 0.74, 1.38, P = 0.93). Conclusions Colorectal cancer prevention and control efforts across the Alaska Tribal Health System have not yet resulted in reduced mortality rates, or induced earlier stage migration. Policy summary statement Intensified efforts will be necessary to reduce the burden of CRC among this high-risk population. Continued and increased focus on primary and secondary prevention efforts is warranted.

Alaska Native (AN) people have among the highest rates of colorectal cancer (CRC) globally. We are developing a community-based participatory research (CBPR) informed program to understand risk and protective factors contributing to these high rates. In 2018, we conducted a pilot study to test feasibility of recruiting participants from the Alaska Native Medical Center CRC Screening Clinic into a prospective epidemiologic study. Post-pilot study completion, we conducted focus groups (n = 2) with participants and key informant interviews (n = 7) with research and clinical staff to understand study experiences. During 106 days of recruitment, 30 participants enrolled in the pilot study. Over half (60%) were female, and most (67%) were aged 40–59 years. Key themes that emerged from the participant focus groups were: the desire to contribute to improving the health of AN people as a key driver of participation; an overall positive experience with the study; the benefit of clinical staff notifying patients about the study; the need to clearly explain the purpose of each biospecimen collected; barriers to participation; and, the importance of returning study results to the community. Key themes from research and clinical staff interviews included: the study not interfering with clinical duties; the importance of relationships between clinical and research staff; the importance of research staff flexibility; and, comments on specific study procedures. As part of the CBPR process, this feedback will be incorporated into study protocols. We are building this pilot work into a larger prospective study that will inform primary prevention programs.

Purpose This study examined the time from breast cancer diagnosis to initiation of treatment among Alaska Native (AN) women. We evaluated the impact of age, cancer stage, and rural/urban residence at diagnosis. Methods We evaluated characteristics of women recorded in the Alaska Native Tumor Registry who received a first diagnosis of breast cancer between 2009 and 2013. Median time from diagnosis to treatment was assessed. Associations of demographic and clinical characteristics with timely initiation of treatment were evaluated using logistic regression and Cox proportional hazards models. Results Two hundred seventy-eight (278) AN women were diagnosed with invasive breast cancer in years 2009-2013. Mean age at diagnosis was 56.8 years (SD = 13.0). The median time from diagnosis to initiation of treatment was 23 days (P < .05) with most (94.6%, n = 263) meeting the ≤60-day guideline target. Time to treatment was not associated with rural/urban residence, age, or stage at cancer diagnosis. Conclusion These findings indicate that most AN women diagnosed with breast cancer within the AN Tribal Health System receive timely treatment after diagnosis.

BACKGROUND AND AIMS: Alaska Native (AN) traditional lifestyle may be protective against chronic disease risk. Weight gain in adulthood has been linked to increases in chronic disease risk among other populations; yet, its impact among Alaska Native people has never been evaluated. We aimed to evaluate changes in obesity-related metrics over time, and determine associations of changes with cardiometabolic markers of chronic disease risk among AN people. METHODS AND RESULTS: Study participants enrolled in the southcentral Alaska Education and Research Towards Health Study in 2004-2006 were invited to participate in a follow-up study conducted 2015-2017. Of the original 1,320 participants, 388 completed health assessments consisting of multiple health surveys, anthropometric measurements, and cardiometabolic measures including blood sugars, blood lipids, and blood pressure. Differences in measurements between visits were determined and associations of weight change with cardiometabolic measures evaluated. Body mass index increased by 3.7 kg/m(2) among men and 4.8 kg/m(2) among women. Hip circumference (1.1 cm, p

Summary of Problem Alaska Native (AN) people experience higher incidence of, and mortality from, gastric cancer compared to other U.S. populations1, 2. Compared to the general U.S. population, gastric cancer in AN people occurs at a younger age, is diagnosed at later stages, is more evenly distributed between the sexes, and is more frequently signet-ring or diffuse histology3. It is known that the prevalence of Helicobacter pylori (Hp) infection, a risk factor for gastric cancer, is high in AN people4; however, high antimicrobial resistance combined with high reinfection rates in Alaska make treatment at the population level complex5. In addition, health issues in AN people are uniquely challenging due to the extremely remote locations of many residents. A multiagency workgroup hosted a symposium in Anchorage that brought internationally-recognized experts and local leaders together to evaluate issues around gastric cancer in the AN population. The overall goal of this symposium was to identify the best strategies to combat gastric cancer in the AN population through prevention and early diagnosis.

Female breast cancer is the most common cancer diagnosed among Alaska Native (AN) women. We examined characteristics of and trends for female breast cancer among AN women. We assessed descriptive statistics, incidence trends (1969–2014), and cause-specific survival for female breast cancers recorded in the Alaska Native Tumor Registry. Results indicated that the majority of breast cancers among AN were diagnosed among women aged over 50 years, at local stage, and with Hormone receptor (HR)+/Human Epidermal Growth Factor (HER) 2− subtype. Five-year average incidence (95% CI) in the most recent time-period (2009–2014) was 145.0/100,000 (130.4, 159.5)); this was not statistically different from the previous time-period. Survival from breast cancer was high and varied by stage and cancer subtype. Hazard of death was greater among those diagnosed with regional/distant/unknown disease, relative to local disease (HR (95%CI): 4.65 (1.66, 12.98)), and higher among those with HER2−/HR− cancers, relative to those with HER2-/HR+ cancers (HR (95%CI): 6.59 (2.23, 19.49)). This study provides a comprehensive description of breast cancer among AN women, providing new and updated information on clinical and demographic factors, cancer incidence trends, regional variations and breast cancer survival. Abbreviations: AIAN: American Indian/Alaska Native; AN: Alaska Native; ANMC: Alaska Native Medical Center; ANTR: Alaska Native Tumor Registry; CI: Confidence Interval; HR: Hazard Ratio; ICD-O-3: International Classification of Diseases for Oncology – Third Edition; NHW – Non-Hispanic Whites; SEER: Surveillance, Epidemiology and End Results.

OBJECTIVE: To evaluate the descriptive epidemiology of pediatric cancers among Alaska Native (AN) people. STUDY DESIGN: We used data from the Alaska Native Tumor Registry, a population-based registry capturing cancer information among Alaska Native people 1969-present. Specifically, we examined all cases of cancer diagnosed among individuals ages 0-19 years. Cases were classified according to the International Classification of Childhood Cancers, 3(rd) edition (ICCC-3). We estimated incidence and distribution of cases by ICCC-3 cancer site, comparing between the time-periods 1969-1996, and 1997-2016. We assessed twelve month and five-year cause-specific survival, and examined differences over time-period, adjusted for age, sex, and ICCC-3 site. RESULTS: Incidence rates of pediatric cancers increased between 1969-1996 (n = 134), and 1997-2016 (n = 186) among Alaska Native people, from 139.8/1,000,000 (95% Confidence Interval (CI): 116.99, 165.7) to 197.54/1,000,000 (95% CI: 170.1, 228.1). Distribution of ICCC-3 sites differed between time-periods (P

Aims This study estimates incidence of diabetes (DM) and pre-DM relative to DM risk factors among relatively healthy Alaska Native and American Indian (henceforth AN) adults living in urban south central Alaska. Methods: Baseline (2004–2006) and follow-up (2014–2017) surveys, blood samples, and medical chart review data were collected from AN adults living in south central Alaska. We analyzed associations between prevalent risk factors and incident DM and pre-DM using Cox proportional hazards and used multivariable models to identify independent predictors for both DM and pre-DM. Results: Among 379 participants with follow-up data, overall DM incidence was 16.5/1,000 PY; overall pre-DM incidence was 77.6/1,000 PY, with marked differences between men and women. Prevalent cardiometabolic risk factors also varied with greater amounts of overweight in men and greater amounts of obesity in women. Controlling for age and sex, obesity, abdominal adiposity, pre-DM, and metabolic syndrome independently increased DM risk. Conclusion: Health care providers of AN populations must seize the opportunity to screen, refer, and treat individuals with pre-DM and other modifiable DM risk factors prior to DM diagnosis if we are to alter the epidemiologic course of disease progression in this urban AN population.

Reliance on self-reported health status information as a measure of population health can be challenging due to errors associated with participant recall. We sought to determine agreement between self-reported and registry-recorded site-specific cancer diagnoses in a cohort of Alaska Native people. We linked cancer history information from the Alaska Education and Research Towards Health (EARTH) cohort and the Alaska Native Tumor Registry (ANTR), and calculated validity measures (sensitivity, specificity, positive predictive value, negative predictive value, kappa). Multiple logistic regression models were used to assess independent associations of demographic variables with incorrect reporting. We found that among Alaska EARTH participants, 140 self-reported a history of cancer, and 99 matched the ANTR. Sensitivity ranged from 79% (colorectal cancer) to 100% (prostate cancer); specificity was over 98% for all-sites examined. Kappa was higher among prostate and female breast cancers (κ=0.86) than colorectal cancers (κ=0.63). Women (odds ratio [OR] (95% confidence interval [CI]): 2.8 (1.49–5.31)) and participants who were older than 50 years (OR (95% CI): 2.8 (1.53–4.12)) were more likely to report incorrectly. These data showed good agreement between self-reported and registry-recorded cancer history. This may be attributed to the high quality of care within the Alaska Tribal Health System, which strongly values patient-provider relationships and the provision of culturally appropriate care.

Recent cancer survival trends among American Indian and Alaska Native (AN) people are not well understood; survival has not been reported among AN people since 2001.This study examined cause-specific survival among AN cancer patients for lung, colorectal, female breast, prostate, and kidney cancers. It evaluated whether survival differed between cancers diagnosed in 1992-2002 (the earlier period) and cancers diagnosed in 2003-2013 (the later period) and by the age at diagnosis (65 vs ≥65 years), stage at diagnosis (local or regional/distant/unknown), and sex. Kaplan-Meier and Cox proportional hazards models were used to estimate univariate and multivariate-adjusted cause-specific survival for each cancer.An improvement was observed in 5-year survival over time from lung cancer (hazard ratio [HR] for the later period vs the earlier period, 0.83; 95% confidence interval [CI], 0.72-0.97), and a marginally nonsignificant improvement was observed for colorectal cancer (HR, 0.81; 95% CI, 0.66-1.01). Site-specific differences in survival were observed by age and stage at diagnosis.This study presents the first data on cancer survival among AN people in almost 2 decades. During this time, AN people have experienced improvements in survival from lung and colorectal cancers. The reasons for these improvements may include increased access to care (including screening) as well as improvements in treatment. Improving cancer survival should be a priority for reducing the burden of cancer among AN people and eliminating cancer disparities. Cancer 2018;124:2570-7. © 2018 American Cancer Society.

The carbon isotope ratio (δ13C) is elevated in corn- and cane sugar-based foods and has recently shown associations with sweetener intake in multiple U.S. populations. However, a high carbon isotope ratio is not specific to corn- and sugar cane-based sweeteners, as other foods, including meats and fish, also have elevated δ13C. This study examines whether the inclusion of a second marker, the nitrogen isotope ratio (δ15N), can control for confounding dietary effects on δ13C and improve the validity of isotopic markers of sweetener intake. The study participants are from the Yup’ik population of southwest Alaska and consume large and variable amounts of fish and marine mammals known to have elevated carbon and nitrogen isotope ratios. Sixty-eight participants completed 4 weekly 24-h recalls followed by a blood draw. RBC δ13C and δ15N were used to predict sweetener intake, including total sugars, added sugars, and sugar-sweetened beverages. A model including both δ13C and δ15N explained more than 3 times as much of the variation in sweetener intake than did a model using only δ13C. Because carbon and nitrogen isotope ratios are simultaneously determined in a single, high-throughput analysis, this dual isotope marker provides a simple method to improve the validity of stable isotope markers of sweetener intake with no additional cost. We anticipate that this multi-isotope approach will have utility in any population where a stable isotope biomarker is elevated in several food groups and there are appropriate “covariate” isotopes to control for intake of foods not of research interest.

The nitrogen isotope ratio (δ(15)N) of RBCs has been proposed as a biomarker of marine food intake in Yup'ik people based on strong associations with RBC eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, EPA and DHA derive from marine fats, whereas elevated δ(15)N derives from marine protein, and these dietary components may have different biologic effects. Whether δ(15)N is similarly associated with chronic disease risk factors compared with RBC EPA and DHA is not known. We used covariate-adjusted linear models to describe biomarker associations with chronic disease risk factors in Yup'ik people, first in a smaller (n = 363) cross-sectional study population using RBC EPA, DHA, and δ(15)N, and then in a larger (n = 772) cross-sectional study population using δ(15)N only. In the smaller sample, associations of RBC EPA, DHA, and δ(15)N with obesity and chronic disease risk factors were similar in direction and significance: δ(15)N was positively associated with total, HDL, and LDL cholesterol, apolipoprotein A-I, and insulin-like growth factor binding protein-3 (IGFBP-3), and inversely associated with triglycerides. Based on comparisons between covariate-adjusted β-coefficients, EPA was more strongly associated with circulating lipids and lipoproteins, whereas δ(15)N was more strongly associated with adipokines, the inflammatory marker interleukin-6, and IGFBP-3. In the larger sample there were new findings for this population: δ(15)N was inversely associated with blood pressure and there was a significant association (with inverse linear and positive quadratic terms) with adiponectin. In conclusion, δ(15)N is a valid measure for evaluating associations between EPA and DHA intake and chronic disease risk in Yup'ik people and may be used in larger studies. By measuring δ(15)N, we report beneficial associations of marine food intake with blood pressure and adiponectin, which may contribute to a lower incidence of some chronic diseases in Yup'ik people.

An objective dietary biomarker would help clarify the contribution of sugar-sweetened beverage (SSB) intake to obesity and chronic disease risk. Previous studies have proposed the carbon isotope ratio (δ(13)C) as a biomarker of SSB intake but found associations that were of modest size and confounded by other components of the diet. We investigated whether the δ(13)C values of nonessential amino acids (δ(13)CNEAA) in RBCs could provide valid biomarkers that are more specific to SSBs. We assessed the associations of RBC δ(13)CNEAA with SSB intake in a study population of 68 Yup'ik people, using gas chromatography/combustion/isotope ratio mass spectrometry to measure δ(13)CNEAA and four 24-h dietary recalls to assess intake. Among RBC nonessential amino acids, alanine δ(13)C (δ(13)Calanine) was strongly correlated with intake of SSBs, added sugar, and total sugar (r = 0.70, 0.59, and 0.57, respectively; P < 0.0001) but uncorrelated with other dietary sources of elevated δ(13)C. We also evaluated whether sweetener intake could be noninvasively assessed using hair δ(13)Calanine in a subset of the study population (n = 30). Hair δ(13)Calanine was correlated with RBC δ(13)Calanine (r = 0.65; P < 0.0001) and showed similar associations with SSB intake. These results show that δ(13)Calanine in RBCs provides a valid and specific biomarker of SSB intake for the Yup'ik population and suggest RBCs and hair δ(13)Calanine as candidate biomarkers of SSB intake for validation in the general U.S. population. Ultimately, these biomarkers could clarify our understanding of whether and how SSB intake contributes to chronic disease.

The transition of a society from traditional to market-based diets (termed the nutrition transition) has been associated with profound changes in culture and health. We are developing biomarkers to track the nutrition transition in the Yup'ik Eskimo population of Southwest Alaska based on naturally occurring variations in the relative abundances of carbon and nitrogen stable isotopes (δ(15)N and δ(13)C values). Here, we provide three pieces of evidence toward the validation of these biomarkers. First, we analyzed the δ(15)N and δ(13)C values of a comprehensive sample of Yup'ik foods. We found that δ(15)N values were elevated in fish and marine mammals and that δ(13)C values were elevated in market foods containing corn or sugar cane carbon. Second, we evaluated the associations between RBC δ(15)N and δ(13)C values and self-reported measures of traditional and market food intake (n = 230). RBC δ(15)N values were correlated with intake of fish and marine mammals (r = 0.52; P0.0001). RBC δ(13)C values were correlated with intake of market foods made from corn and sugar cane (r = 0.46; P0.0001) and total market food intake (r = 0.46; P0.0001). Finally, we assessed whether stable isotope ratios captured population-level patterns of traditional and market intake (n = 1003). Isotopic biomarkers of traditional and market intake were associated with age, community location, sex, and cultural identity. Self-report methods showed variations by age and cultural identity only. Thus, stable isotopes show potential as biomarkers for monitoring dietary change in indigenous circumpolar populations.