Incidence of Stomach, Liver, and Colorectal Cancers by Geography and Social Vulnerability Among American Indian and Alaska Native Populations, 2010-2019.

Social determinants of health and associated systems, policies, and practices are important drivers of health disparities. American Indian and Alaska Native (AI/AN) populations in the United States have elevated incidence rates of stomach, liver, and colorectal cancers compared with other racial/ethnic groups. In this study, we examined incidence rates of 3 types of gastrointestinal cancer among non-Hispanic AI/AN (NH-AI/AN) and non-Hispanic White (NHW) populations by geographic region and Social Vulnerability Index (SVI) score. Incident cases diagnosed during 2010-2019 were identified from population-based cancer registries linked with the Indian Health Service patient registration databases. Age-adjusted incidence rates (per 100,000 population) for stomach, liver, and colorectal cancers were compared within NH-AI/AN populations and between the NH-AI/AN and NHW populations by SVI score. Rates were higher among NH-AI/AN populations in moderate- and high-SVI-score counties in Alaska, the Southern Plains, and the East than in low-SVI counties. Incidence rates among NH-AI/AN populations were elevated when compared with NHW populations by SVI category. Results indicated that higher social vulnerability may drive elevated cancer incidence among NH-AI/AN populations. Additionally, disparities between NH-AI/AN and NHW populations persist even when accounting for SVI. Exploring social vulnerability can aid in designing more effective interventions to address root causes of cancer disparities among AI/AN populations.

Disparities in incidence and trends of colorectal, lung, female breast, and cervical cancers among non-Hispanic American Indian and Alaska Native people, 1999-2018.

PURPOSE: This study is the first to comprehensively describe incidence rates and trends of screening-amenable cancers (colorectal, lung, female breast, and cervical) among non-Hispanic AI/AN (NH-AI/AN) people. METHODS: Using the United States Cancer Statistics AI/AN Incidence Analytic Database, we, calculated incidence rates for colorectal, lung, female breast, and cervical cancers for NH-AI/AN and non-Hispanic White (NHW) people for the years 2014-2018 combined. We calculated age-adjusted incidence rates (per 100,000), total percent change in incidence rates between 1999 and 2018, and trends over this time-period using Joinpoint analysis. Screening prevalence by region was calculated using Behavioral Risk Factor Surveillance System data. RESULTS: Rates of screening-amenable cancers among NH-AI/AN people varied by geographic region and age at diagnosis. Over half of all lung and colorectal cancers in NH-AI/AN people were diagnosed at later stages. Rates of lung and colorectal cancers decreased significantly between 1999-2018 among NH-AI/AN men, but no significant changes were observed in rates of screening-amenable cancers among NH-AI/AN women. CONCLUSION: This study highlights disparities in screening-amenable cancers between NH-AI/AN and NHW people. Culturally informed, community-based interventions that increase access to preventive health services could reduce cancer disparities among AI/AN people.

Cancer disparities among non-Hispanic urban American Indian and Alaska Native populations in the United States, 1999-2017.

BACKGROUND: Disparities in cancer incidence have not been described for urban American Indian/Alaska Native (AI/AN) populations. The purpose of the present study was to examine incidence rates (2008-2017) and trends (1999-2017) for leading cancers in urban non-Hispanic AI/AN (NH AI/AN) compared to non-Hispanic White (NHW) populations living in the same urban areas. METHODS: Incident cases from population-based cancer registries were linked with the Indian Health Service patient registration database for improved racial classification of NH AI/AN populations. This study was limited to counties in Urban Indian Health Organization service areas. Analyses were conducted by geographic region. Age-adjusted rates (per 100,000) and trends (joinpoint regression) were calculated for leading cancers. RESULTS: Rates of colorectal, liver, and kidney cancers were higher overall for urban NH AI/AN compared to urban NHW populations. By region, rates of these cancers were 10% to nearly 4 times higher in NH AI/AN compared to NHW populations. Rates for breast, prostate, and lung cancer were lower in urban NH AI/AN compared to urban NHW populations. Incidence rates for kidney, liver, pancreatic, and breast cancers increased from 2% to nearly 7% annually between 1999 to 2017 in urban NH AI/AN populations. CONCLUSIONS: This study presents cancer incidence rates and trends for the leading cancers among urban NH AI/AN compared to urban NHW populations for the first time, by region, in the United States. Elevated risk of certain cancers among urban NH AI/AN populations and widening cancer disparities highlight important health inequities and missed opportunities for cancer prevention in this population.

COVID-19 Among Non-Hispanic American Indian and Alaska Native People Residing in Urban Areas Before and After Vaccine Rollout-Selected States and Counties, United States, January 2020-October 2021.

Objectives. To evaluate COVID-19 disparities among non-Hispanic American Indian/Alaska Native (AI/AN) and non-Hispanic White persons in urban areas. Methods. Using COVID-19 case surveillance data, we calculated cumulative incidence rates and risk ratios (RRs) among non-Hispanic AI/AN and non-Hispanic White persons living in select urban counties in the United States by age and sex during January 22, 2020, to October 19, 2021. We separated cases into prevaccine (January 22, 2020-April 4, 2021) and postvaccine (April 5, 2021-October 19, 2021) periods. Results. Overall in urban areas, the COVID-19 age-adjusted rate among non-Hispanic AI/AN persons (n = 47 431) was 1.66 (95% confidence interval [CI] = 1.36, 2.01) times that of non-Hispanic White persons (n = 2 301 911). The COVID-19 prevaccine age-adjusted rate was higher (8227 per 100 000; 95% CI = 6283, 10 770) than was the postvaccine rate (3703 per 100 000; 95% CI = 3235, 4240) among non-Hispanic AI/AN compared with among non-Hispanic White persons (2819 per 100 000; 95% CI = 2527, 3144; RR = 1.31; 95% CI = 1.17, 1.48). Conclusions. This study highlights disparities in COVID-19 between non-Hispanic AI/AN and non-Hispanic White persons in urban areas. These findings suggest that COVID-19 vaccination and other public health efforts among urban AI/AN communities can reduce COVID-19 disparities in urban AI/AN populations. (Am J Public Health. 2022;112(10):1489-1497. https://doi.org/10.2105/AJPH.2022.306966).

Incidence of and Trends in the Leading Cancers With Elevated Incidence Among American Indian and Alaska Native Populations, 2012-2016.

Cancer incidence varies among American Indian and Alaska Native (AI/AN) populations, as well as between AI/AN and White populations. This study examined trends for cancers with elevated incidence among AI/AN compared with non-Hispanic White populations and estimated potentially avoidable incident cases among AI/AN populations. Incident cases diagnosed during 2012-2016 were identified from population-based cancer registries and linked with the Indian Health Service patient registration databases to improve racial classification of AI/AN populations. Age-adjusted rates (per 100,000) and trends were calculated for cancers with elevated incidence among AI/AN compared with non-Hispanic White populations (rate ratio of >1.0) according to region. Trends were estimated using joinpoint regression analyses. Expected cancers were estimated by applying age-specific cancer incidence rates among non-Hispanic White populations to population estimates for AI/AN populations. Excess cancer cases among AI/AN populations were defined as observed minus expected cases. Liver, stomach, kidney, lung, colorectal, and female breast cancers had higher incidence rates among AI/AN populations across most regions. Between 2012 and 2016, nearly 5,200 excess cancers were diagnosed among AI/AN populations, with the largest number of excess cancers (1,925) occurring in the Southern Plains region. Culturally informed efforts could reduce cancer disparities associated with these and other cancers among AI/AN populations.

Gastric Cancer Among American Indian and Alaska Native Populations in the United States, 2005-2016.

INTRODUCTION: American Indian and Alaska Native (AI/AN) populations have higher gastric cancer rates than the general US population. This study provides a comprehensive overview of incidence rates among AI/AN persons during 2005-2016 compared with non-Hispanic whites (whites). METHODS: Population-based cancer registry data for 2005-2016 were linked with the Indian Health Service patient registration databases to address racial misclassification. Age-adjusted gastric cancer incidence rates were expressed per 100,000 per year. Incidence and trend analyses were restricted to purchased/referred care delivery area counties in 6 geographic regions, comparing gastric cancer incidence rates for AI/AN vs white populations in the United States. RESULTS: Gastric cancer rates were higher in the AI/AN compared with white populations in nearly every US region. Incidence rates for central/distal portions of the stomach were higher in AI/AN individuals compared with whites. Rates of later stage gastric cancer were higher in AI/AN populations overall and in every region except the Pacific Coast and East. Incidence rates decreased significantly over time in both populations. Declining rates in the AI/AN populations were driven by changes in the Pacific Coast and Northern Plains regions. DISCUSSION: AI/AN populations have a disproportionately high incidence of gastric cancer, especially in Alaska. High incidence in the central/distal portions of the stomach among AI/AN populations likely reflects a high prevalence of Helicobacter pylori infection in these populations. These data can be used to develop interventions to reduce risk factors and improve access to health services among AI/AN people at high risk for gastric cancer.

Cancers Associated with Human Papillomavirus in American Indian and Alaska Native Populations - United States, 2013-2017.

Human papillomavirus (HPV) causes most cervical cancers and some cancers of the penis, vulva, vagina, oropharynx, and anus. Cervical precancers can be detected through screening. HPV vaccination with the 9-valent HPV vaccine (9vHPV) can prevent approximately 92% of HPV-attributable cancers (1).* Previous studies have shown lower incidence of HPV-associated cancers in non-Hispanic American Indian and Alaska Native (AI/AN) populations compared with other racial subgroups (2); however, these rates might have been underestimated as a result of racial misclassification. Previous studies have shown that cancer registry data corrected for racial misclassification resulted in more accurate cancer incidence estimates for AI/AN populations (3,4). In addition, regional variations in cancer incidence among AI/AN populations suggest that nationally aggregated data might not adequately describe cancer outcomes within these populations (5). These variations might, in part, result from geographic disparities in the use of health services, such as cancer screening or vaccination (6). CDC analyzed data for 2013-2017 from central cancer registries linked with the Indian Health Service (IHS) patient registration database to assess the incidence of HPV-associated cancers and to estimate the number of cancers caused by HPV among AI/AN populations overall and by region. During 2013-2017, an estimated 1,030 HPV-associated cancers were reported in AI/AN populations. Of these cancers, 740 (72%) were determined to be attributable to HPV types targeted by 9vHPV; the majority were cervical cancers in females and oropharyngeal cancers in males. These data can help identify regions where AI/AN populations have disproportionately high rates of HPV-associated cancers and inform targeted regional vaccination and screening programs in AI/AN communities.

COVID-19 Among American Indian and Alaska Native Persons - 23 States, January 31-July 3, 2020.

Although non-Hispanic American Indian and Alaska Native (AI/AN) persons account for 0.7% of the U.S. population,* a recent analysis reported that 1.3% of coronavirus disease 2019 (COVID-19) cases reported to CDC with known race and ethnicity were among AI/AN persons (1). To assess the impact of COVID-19 among the AI/AN population, reports of laboratory-confirmed COVID-19 cases during January 22†-July 3, 2020 were analyzed. The analysis was limited to 23 states§ with >70% complete race/ethnicity information and five or more laboratory-confirmed COVID-19 cases among both AI/AN persons (alone or in combination with other races and ethnicities) and non-Hispanic white (white) persons. Among 424,899 COVID-19 cases reported by these states, 340,059 (80%) had complete race/ethnicity information; among these 340,059 cases, 9,072 (2.7%) occurred among AI/AN persons, and 138,960 (40.9%) among white persons. Among 340,059 cases with complete patient race/ethnicity data, the cumulative incidence among AI/AN persons in these 23 states was 594 per 100,000 AI/AN population (95% confidence interval [CI] = 203-1,740), compared with 169 per 100,000 white population (95% CI = 137-209) (rate ratio [RR] = 3.5; 95% CI = 1.2-10.1). AI/AN persons with COVID-19 were younger (median age = 40 years; interquartile range [IQR] = 26-56 years) than were white persons (median age = 51 years; IQR = 32-67 years). More complete case report data and timely, culturally responsive, and evidence-based public health efforts that leverage the strengths of AI/AN communities are needed to decrease COVID-19 transmission and improve patient outcomes.

Incidence of primary liver cancer in American Indians and Alaska Natives, US, 1999-2009.

PURPOSE: To evaluate liver cancer incidence rates and risk factor correlations in non-Hispanic AI/AN populations for the years 1999-2009. METHODS: We linked data from 51 central cancer registries with the Indian Health Service patient registration databases to improve identification of the AI/AN population. Analyses were restricted to non-Hispanic persons living in Contract Health Service Delivery Area counties. We compared age-adjusted liver cancer incidence rates (per 100,000) for AI/AN to white populations using rate ratios. Annual percent changes (APCs) and trends were estimated using joinpoint regression analyses. We evaluated correlations between regional liver cancer incidence rates and risk factors using Pearson correlation coefficients. RESULTS: AI/AN persons had higher liver cancer incidence rates than whites overall (11.5 versus 4.8, RR = 2.4, 95% CI 2.3-2.6). Rate ratios ranged from 1.6 (Southwest) to 3.4 (Northern Plains and Alaska). We observed an increasing trend among AI/AN persons (APC 1999-2009 = 5%). Rates of distant disease were higher in the AI/AN versus white population for all regions except Alaska. Alcohol use (r = 0.84) and obesity (r = 0.79) were correlated with liver cancer incidence by region. CONCLUSIONS: Findings highlight disparities in liver cancer incidence between AI/AN and white populations and emphasize opportunities to decrease liver cancer risk factor prevalence.

Stomach cancer survival in the United States by race and stage (2001-2009): Findings from the CONCORD-2 study.

BACKGROUND: Stomach cancer was a leading cause of cancer-related deaths early in the 20th century and has steadily declined over the last century in the United States. Although incidence and death rates are now low, stomach cancer remains an important cause of morbidity and mortality in black, Asian and Pacific Islander, and American Indian/Alaska Native populations. METHODS: Data from the CONCORD-2 study were used to analyze stomach cancer survival among males and females aged 15 to 99 years who were diagnosed in 37 states covering 80% of the US population. Survival analyses were corrected for background mortality using state-specific and race-specific (white and black) life tables and age-standardized using the International Cancer Survival Standard weights. Net survival is presented up to 5 years after diagnosis by race (all, black, and white) for 2001 through 2003 and 2004 through 2009 to account for changes in collecting Surveillance, Epidemiology, and End Results Summary Stage 2000 data from 2004. RESULTS: Almost one-third of stomach cancers were diagnosed at a distant stage among both whites and blacks. Age-standardized 5-year net survival increased between 2001 to 2003 and 2004 to 2009 (26.1% and 29%, respectively), and no differences were observed by race. The 1-year, 3-year, and 5-year survival estimates were 53.1%, 33.8%, and 29%, respectively. Survival improved in most states. Survival by stage was 64% (local), 28.2% (regional), and 5.3% (distant). CONCLUSIONS: The current results indicate high fatality for stomach cancer, especially soon after diagnosis. Although improvements in stomach cancer survival were observed, survival remained relatively low for both blacks and whites. Primary prevention through the control of well-established risk factors would be expected to have the greatest impact on further reducing deaths from stomach cancer. Cancer 2017;123:4994-5013. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Period life tables for the non-Hispanic American Indian and Alaska Native population, 2007-2009.

OBJECTIVES: We estimated complete period life tables for the non-Hispanic American Indian and Alaska Native (AI/AN) population residing in Contract Health Service Delivery Area (CHSDA) counties for the period 2007-2009. METHODS: We used National Vital Statistics System mortality data files for years 2007-2009 corrected for AI/AN misclassification on death certificates, midyear 2008 revised census bridged race intercensal population estimates, and National Vital Statistics System birth data for years 2006-2009. We used the same methodology as that used to estimate official US annual life tables, with some minor modifications. RESULTS: For the period 2007-2009, the non-Hispanic AI/AN population in CHSDA counties had the lowest life expectancy at birth (71.1 years) of any racial/ethnic group for which official US life tables are estimated. By comparison, in 2008, life expectancy at birth was 73.9 years for the non-Hispanic Black population, 78.4 years for the non-Hispanic White population, and 80.8 years for the Hispanic population. CONCLUSIONS: The life tables showed a clear mortality disadvantage for the non-Hispanic AI/AN population in CHSDA counties relative to other national populations. The findings suggested that further research is necessary to explore the causes behind these disadvantages.

Leading causes of death and all-cause mortality in American Indians and Alaska Natives.

OBJECTIVES: We present regional patterns and trends in all-cause mortality and leading causes of death in American Indians and Alaska Natives (AI/ANs). METHODS: US National Death Index records were linked with Indian Health Service (IHS) registration records to identify AI/AN deaths misclassified as non-AI/AN. We analyzed temporal trends for 1990 to 2009 and comparisons between non-Hispanic AI/AN and non-Hispanic White persons by geographic region for 1999 to 2009. Results focus on IHS Contract Health Service Delivery Area counties in which less race misclassification occurs. RESULTS: From 1990 to 2009 AI/AN persons did not experience the significant decreases in all-cause mortality seen for Whites. For 1999 to 2009 the all-cause death rate in CHSDA counties for AI/AN persons was 46% more than that for Whites. Death rates for AI/AN persons varied as much as 50% among regions. Except for heart disease and cancer, subsequent ranking of specific causes of death differed considerably between AI/AN and White persons. CONCLUSIONS: AI/AN populations continue to experience much higher death rates than Whites. Patterns of mortality are strongly influenced by the high incidence of diabetes, smoking prevalence, problem drinking, and social determinants. Much of the observed excess mortality can be addressed through known public health interventions.

Methods for improving the quality and completeness of mortality data for American Indians and Alaska Natives.

OBJECTIVES: We describe methods used to mitigate the effect of race misclassification in mortality records and the data sets used to improve mortality estimates for American Indians and Alaska Natives (AI/ANs). METHODS: We linked US National Death Index (NDI) records with Indian Health Service (IHS) registration records to identify AI/AN deaths misclassified as non-AI/AN deaths. Analyses excluded decedents of Hispanic origin and focused on Contract Health Service Delivery Area (CHSDA) counties. We compared death rates for AI/AN persons and Whites across 6 US regions. RESULTS: IHS registration records merged to 176,137 NDI records. Misclassification of AI/AN race in mortality data ranged from 6.3% in the Southwest to 35.6% in the Southern Plains. From 1999 to 2009, the all-cause death rate in CHSDA counties for AI/AN persons varied by geographic region and was 46% greater than that for Whites. Analyses for CHSDA counties resulted in higher death rates for AI/AN persons than in all counties combined. CONCLUSIONS: Improving race classification among AI/AN decedents strengthens AI/AN mortality data, and analyzing deaths by geographic region can aid in planning, implementation, and evaluation of efforts to reduce health disparities in this population.

Kidney cancer incidence and mortality among American Indians and Alaska Natives in the United States, 1990-2009.

OBJECTIVES: We describe rates and trends in kidney cancer incidence and mortality and identify disparities between American Indian/Alaska Native (AI/AN) and White populations. METHODS: To improve identification of AI/AN race, incidence and mortality data were linked with Indian Health Service (IHS) patient records. Analysis focused on residents of IHS Contract Health Service Delivery Area counties; Hispanics were excluded. We calculated age-adjusted kidney cancer incidence (2001-2009) and death rates (1990-2009) by sex, age, and IHS region. RESULTS: AI/AN persons have a 1.6 times higher kidney cancer incidence and a 1.9 times higher kidney cancer death rate than Whites. Despite a significant decline in kidney cancer death rates for Whites (annual percentage change [APC] = -0.3; 95% confidence interval [CI] = -0.5, 0.0), death rates for AI/AN persons remained stable (APC = 0.4; 95% CI = -0.7, 1.5). Kidney cancer incidence rates rose more rapidly for AI/AN persons (APC = 3.5; 95% CI = 1.2, 5.8) than for Whites (APC = 2.1; 95% CI = 1.4, 2.8). CONCLUSIONS: AI/AN individuals have greater risk of developing and dying of kidney cancers. Incidence rates have increased faster in AI/AN populations than in Whites. Death rates have decreased slightly in Whites but remained stable in AI/AN populations. Racial disparities in kidney cancer are widening.

Racial misclassification of American Indians and Alaska Natives by Indian Health Service Contract Health Service Delivery Area.

OBJECTIVES: We evaluated the racial misclassification of American Indians and Alaska Natives (AI/ANs) in cancer incidence and all-cause mortality data by Indian Health Service (IHS) Contract Health Service Delivery Area (CHSDA). METHODS: We evaluated data from 3 sources: IHS-National Vital Statistics System (NVSS), IHS-National Program of Cancer Registries (NPCR)/Surveillance, Epidemiology and End Results (SEER) program, and National Longitudinal Mortality Study (NLMS). We calculated, within each data source, the sensitivity and classification ratios by sex, IHS region, and urban-rural classification by CHSDA county. RESULTS: Sensitivity was significantly greater in CHSDA counties (IHS-NVSS: 83.6%; IHS-NPCR/SEER: 77.6%; NLMS: 68.8%) than non-CHSDA counties (IHS-NVSS: 54.8%; IHS-NPCR/SEER: 39.0%; NLMS: 28.3%). Classification ratios indicated less misclassification in CHSDA counties (IHS-NVSS: 1.20%; IHS-NPCR/SEER: 1.29%; NLMS: 1.18%) than non-CHSDA counties (IHS-NVSS: 1.82%; IHS-NPCR/SEER: 2.56%; NLMS: 1.81%). Race misclassification was less in rural counties and in regions with the greatest concentrations of AI/AN persons (Alaska, Southwest, and Northern Plains). CONCLUSIONS: Limiting presentation and analysis to CHSDA counties helped mitigate the effects of race misclassification of AI/AN persons, although a portion of the population was excluded.

Kidney Cancer Incidence among Non-Hispanic American Indian and Alaska Native Populations in the United States, 1999 to 2020.

BACKGROUND: Non-Hispanic American Indian and Alaska Native (NH-AI/AN) people exhibit a disproportionate incidence of kidney cancer. Nationally aggregated data do not allow for a comprehensive description of regional disparities in kidney cancer incidence among NH-AI/AN communities. This study examined kidney cancer incidence rates and trends among NH-AI/AN compared with non-Hispanic White (NHW) populations by geographic region. METHODS: Using the United States Cancer Statistics American Indian and Alaska Native (AI/AN) Incidence Analytic Database, age-adjusted incidence rates (per 100,000) of kidney cancers for NH-AI/AN and NHW people for the years 2011 to 2020 combined using surveillance, epidemiology, and end Results (SEER)∗stat software. Analyses were restricted to non-Hispanic individuals living in purchased/referred care delivery area (PRCDA) counties. Average annual percent changes (AAPCs) and trends (1999-2019) were estimated using Joinpoint regression analyses. RESULTS: Rates of kidney cancer incidence were higher among NH-AI/AN compared with NHW persons in the United States overall and in five of six regions. Kidney cancer incidence rates also varied by region, sex, age, and stage of diagnosis. Between 1999 and 2019, trends in kidney cancer rates significantly increased among NH-AI/AN males (AAPC = 2.7%) and females (AAPC = 2.4%). The largest increases were observed for NH-AI/AN males and females aged less than 50 years and those diagnosed with localized-stage disease. CONCLUSIONS: Study findings highlight growing disparities in kidney cancer incidence rates between NH-AI/AN and NHW populations. IMPACT: Differences in geographic region, sex, and stage highlight the opportunities to decrease the prevalence of kidney cancer risk factors and improve access to preventive care.

Melanoma Incidence Rates Among Non-Hispanic American Indian/Alaska Native Individuals, 1999-2019.

Importance: Non-Hispanic American Indian/Alaska Native people have the second highest incidence rate of invasive cutaneous melanoma in the US after non-Hispanic White people. Objective: To examine invasive cutaneous melanoma incidence rates and trends over time among non-Hispanic American Indian/Alaska Native people. Design, Setting, and Participants: This descriptive, observational cross-sectional study used population-based cancer registry data (US Cancer Statistics AI/AN Incidence Analytic Database) linked to the Indian Health Service administrative database to examine incidence rates by age, sex, region, histology, tumor site, stage, and other demographic and clinical characteristics. The study examined trends from 1999 to 2019 time period by age, sex, stage at diagnosis, and region. Non-Hispanic American Indian/Alaska Native people 15 years and older who received a diagnosis of invasive cutaneous melanoma from 1999 to 2019 who were members of federally recognized tribes and resided in Indian Health Service purchased/referred care delivery areas were included in this study to reduce racial misclassification and provide more accurate rates. The data were analyzed in 2022. Exposures: Demographic and clinical characteristics, such as age, sex, geographic region, histology, stage, and tumor site. Main Outcomes and Measures: Invasive cutaneous melanoma incidence rates by age group, sex, region, resident county characteristics (poverty level, rurality, education level, and socioeconomic status), stage at diagnosis, tumor site, and histology. Trends over time by age, sex, region, and stage. Results: From 1999 to 2019, 2151 non-Hispanic American Indian/Alaska Native people (1021 female individuals [47.5%]) received a diagnosis of incident cutaneous melanoma (rate, 10.7 per 100 000; 95% CI, 10.3-11.2). Rates were higher among male than female individuals (13.0 [95% CI, 12.2-13.8] vs 9.2 [95% CI, 8.6-9.8]) and for people 55 years and older (24.2; 95% CI, 22.8-25.7) compared with those aged 15 to 39 years (3.5; 95% CI, 3.2-3.9). Rates were highest for male individuals 55 years and older (34.5; 95% CI, 31.8-37.3) and people living in the Southern Plains (male individuals: 23.8; 95% CI, 21.5-26.2; female individuals: 15.5; 95% CI, 14.0-17.2) and Pacific Coast region (male individuals: 16.5; 95% CI, 14.5-18.7; female individuals: 12.3; 95% CI, 10.9-13.9). Rates increased among female individuals from 1999 to 2019 (average annual percent change [AAPC], 2.5; P < .001); among regional/distant stage tumors (AAPC, 2.5; P = .01) and people 55 years and older (AAPC, 2.8; P = .001). Conclusions and Relevance: The results of this study suggest that additional studies could potentially identify risk factors among non-Hispanic American Indian/Alaska Native people.

Incidence of selected cancers in Non-Hispanic American Indian and Alaska Native adolescent and young adult populations, 1999-2019.

PURPOSE: Studies have highlighted geographic variation in cancer incidence rates among American Indian and Alaska Native (AI/AN) populations. This is the first study to comprehensively evaluate incidence rates and trends among non-Hispanic AI/AN (NH-AI/AN) adolescents and young adults (AYAs) ages 15-39 years. METHODS: Using the United States Cancer Statistics AI/AN Incidence Analytic Database, we identified all malignant cancer cases for NH-AI/AN AYA populations for the years 1999-2019. We calculated age-adjusted incidence rates (per 100,000) for NH-AI/AN populations overall, by region, and by age group. We calculated the total percent change in the incidence of leading AYA cancers between 1999 and 2019, and trends by region and cancer type using Joinpoint analysis. RESULTS: Testicular (13.6) and breast (19.0) cancers had the highest incidence of all AYA cancers in NH-AI/AN males and females, respectively. Overall AYA cancer rates increased by 1.4% in NH-AI/AN males and 1.8% in NH-AI/AN females annually between 1999 and 2019. Increases were observed by age group and geographic region. CONCLUSIONS: This study describes regional differences in incidence rates of AYA cancers among NH-AI/AN populations. This data can help inform resource and cancer control priorities and strategies to reduce cancer risk and enhance access to quality diagnostic and treatment services for this population.

Impact of hysterectomy and bilateral oophorectomy prevalence on rates of cervical, uterine, and ovarian cancer among American Indian and Alaska Native women, 1999-2004.

OBJECTIVE: To present more accurate incidence rates of cervical, uterine, and ovarian cancer by geographic region in American Indian/Alaska Native (AI/AN) women. METHODS: The authors used data from central cancer registries linked to Indian Health Service (IHS) patient registration database, the Behavioral Risk Factor Surveillance System, IHS National Data Warehouse, and the National Hospital Discharge Survey. Cancer incidence rates were adjusted for hysterectomy and oophorectomy prevalence and presented by region for non-Hispanic White (NHW) and AI/AN women. RESULTS: AI/AN women had a higher prevalence of hysterectomy (23.1%) compared with NHW women (20.9%). Correcting cancer rates for population-at-risk significantly increased the cancer incidence rates among AI/AN women: 43% for cervical cancer, 67% for uterine cancer, and 37% for ovarian cancer. Risk-correction led to increased differences in cervical cancer incidence between AI/AN and NHW women in certain regions. CONCLUSIONS: Current reporting of cervical, uterine, and ovarian cancer underestimates the incidence in women at risk and can affect the measure of cancer disparities. Improved cancer surveillance using methodology to correct for population-at-risk may better inform disease control priorities for AI/AN populations.