Incident cancers among participants of the Alaska EARTH study, and associations with known cancer risk factors.

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1 Incident cancers among participants of the Alaska EARTH study, and associations with known cancer risk factors. Sarah Nash, Cancer Surveillance Director, Alaska Native Tribal Health Consortium June 12 th 2018 NAACCR Annual Meeting

2 Cancer is a leading cause of morbidity among AN people 25% 2% 2% 2% 2% 4% 4% 24% 14% Years of Potential Life Lost among Alaska Native people, % 12% Unintentional Injury Suicide Cancer Heart disease Chronic Liver disease Homicide Alcohol Abuse Perinatal conditions Congenital Malformations Pneumonia & Influenza Other causes Source: State of Alaska Bureau of Vital Statistics; Alaska Native EpiCenter Alaska Native Mortality Update

3 Cancer is the leading cause of mortality among Alaska Native people 2% 2% 2% 27% 3% 4% 5% 6% 13% 21% 17% Between , cancer accounted for over 1/5 of all deaths among AN people Cancer Heart disease Unintentional Injury Suicide COPD Cerebrovascular disease Chronic Liver disease Pneumonia & Influenza Diabetes Alcohol Abuse Other causes Source: State of Alaska Bureau of Vital Statistics; Alaska Native EpiCenter Alaska Native Mortality Update

4 The Alaska EARTH cohort study Part of a multisite cohort study to better understand risk factors for cancer and other chronic diseases among AI/AN people.

5 Risk and protective factors for cancer among AN EARTH participants Risk factors: Tobacco use Physical inactivity Overweight and obesity Less healthy metabolic profile

6 Risk and protective factors for cancer among AN EARTH participants Protective factors: Low nulliparity Low use of menopausal estrogens Common use of contraceptive hormones High prevalence of screening AN traditional food use and cultural activities

7 Limitations of previous studies Generalizability: Alaska EARTH cohort representative of AN people statewide by age and education, but the degree to which they represent their cancer experience is unknown. Longditudinality: Previous studies of risk/ protective factors are all cross-sectional

8 Goals of this study Link the Alaska EARTH cohort with the Alaska Native Tumor Registry: Establish the number and site of incident cancers since study baseline ( ). Examine associations of major cancer risk factors with cancer incidence.

9 Methods: Study Population and Data Sources Alaska EARTH Study Recruited from 3 regions: Southcentral, Southeast, Southwest. Baseline recruitment Study visit included: informed consent, medical and anthropometric measurements, diet history, medical record review, questionnaire SEER Alaska Native Tumor Registry Record cancer information for all AI/AN IHS beneficiaries resident in AK at time of diagnosis. Linkage based on name, DOB, SSN.

10 Methods: Cancer case counts and incidence Cohort-specific counts/rates compared to statewide and regional population-based data from ANTR ( ), using SEER population data. Person-time Alaska EARTH participants calculated as time between date of study enrollment and date of cancer incidence (event), administrative censoring (12/31/15), or death. All rates age-adjusted to the 2000 US Standard Population.

11 Methods: Risk factor associations Associations examined with all-sites incidence only, due to low case counts. Risk factors: smoking (never/ever), BMI (obese/nonobese), meets CDC physical activity recommendations (yes/no). Univariate and multivariable-adjusted Cox proportional hazards models, adjusted for the demographic variables age, sex, and rural/urban residence.

12 Demographic characteristics Alaska EARTH with no history of cancer Alaska EARTH matched to ANTR n =3,539 n =173 P-value a Demographic characteristics Age (years, Mean [SD]) 39.3(14.5) 52.9(13.0) < Age at cancer diagnosis (years, mean [SD]) (12.8) Sex (% Female) 2138 (60.4) 99(57.9) 0.51 Educational attainment (% <12 years) 766 (21.6) 44 (25.4) 0.21 Language (% English as the primary language at home) 3249 (92.1) 154 (90.1) 0.32 Residence (% rural) 2254 (63.4) 114 (66.7) 0.43

13 Cancer risk factors Alaska EARTH with no history of cancer Alaska EARTH matched to ANTR P-value a n =3,539 n =173 BMI (kg/m2) mean (SD) 29.9 (6.9) 31.2 (7.9) healthy weight (%) 917 (26.1) 38 (22.5) overweight 1130 (32.0) 46 (27.2) obese 1472 (41.7) 85 (50.3) Smoking 0.09 Never 1260 (39.1) 51 (32.3) 0.06 Former 838 (26.0) 54 (34.2) Current 1127 (35.0) 53 (33.5) Servings fruit/vegetable per day Meets fruit/vegetable recommendations (% yes)n=2701 Mean hours of moderate to vigorous physical activity/wk Meets physical activity recommendations (% yes) 1127 (43.8) (32.9) 63 (48.5) (15.2) 11.5 (9.0) (70.4) 89 (59.7) 0.006

14 Cancers diagnosed among Alaska EARTH participants During the period of follow-up: Total: n = 173 cancer cases Female breast, n = 41 Colorectal, n = 27 Lung and bronchus, n = 27 Stomach, n = 7 Prostate, n = 7 Kidney, n = 7 These leading cancers mirror those observed for AN people statewide

15 Cancer incidence rates: EARTH cohort vs ANTR statewide 700 Age-adjusted Incidence Rate ANTR EARTH 0 All sites Breast Lung Colorectal Other aincidence rate given per 100,000 person years for Alaska EARTH study participants, and per 100,000 population for AN people statewide.

16 Cancer incidence rates: regional comparisons 1000 Age-adjusted Incidence Rate All sites Breast Lung Colorectal Other ANTR SC EARTH SC ANTR SE EARTH SE ANTR SW EARTH SW aincidence rate given per 100,000 person years for Alaska EARTH study participants, and per 100,000 population for AN people statewide.

17 Associations of cancer incidence with cancer risk factors Variables Smoker (Ever vs. Never) Univariate Estimates Hazard 95% CI p-value Ratio Cancer risk factors Multivariable-adjusted Estimates Hazard 95% CI p-value Ratio Obese (Yes vs. No) Not Active (Yes vs. No) Sex (Male vs. Female) Age (>55 vs. <55 years) Rural (urban vs. rural) Demographic variables

18 Summary Leading cancers in the Alaska EARTH cohort mirrored those observed for AN people statewide. Cancer incidence rates (all-sites, site-specific) were generally statistically similar, overall, and by region. Exception: breast cancer incidence was higher among southeast Alaska EARTH participants. Individuals with a history of smoking were at a slightly increased risk of developing cancer, as well as males, older individuals, and those who lived at the urban site.

19 Strengths and Limitations Strengths: Leveraging two existing AN cancerrelated resources. First study to examine longitudinal associations of cancer risk among AN people. Limitations: Small case counts: limited statistical power. Self-report measures of cancer risk factors. Generalizability: convenience sample for EARTH.

20 Acknowledgements Coauthors: ANTHC Garrett Zimpelman Gretchen Day Kathy Koller Southcentral Foundation Vanessa Hiratsuka The Alaska Native Tumor Registry is funded by the NCI s Surveillance, Epidemiology and End Results Program, NCI contract number HHSN I, Task Order HHSN The Alaska EARTH study was funded by NCI grants CA88958 and CA The content of this presentation is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

21 Sarah Nash, PhD MPH CPH Cancer Surveillance Director TEL: