Methods for improving cancer surveillance data in American Indian and Alaska Native populations

The impact of adjusting for hysterectomy prevalence on cervical cancer incidence rates and trends among women aged 30 years or older-United States, 2001-2019

Hysterectomy protects against cervical cancer when the cervix is removed. However, measures of cervical cancer incidence often fail to exclude women with a hysterectomy from the population-at-risk denominator, underestimating and distorting disease burden. In this study, we estimated hysterectomy prevalence from the Behavioral Risk Factor Surveillance System surveys to remove the women who were not at risk of cervical cancer from the denominator and combined these estimates with the US Cancer Statistics data. From these data, we calculated age-specific and age-standardized incidence rates for women aged >30 years from 2001-2019, adjusted for hysterectomy prevalence. We calculated the difference between unadjusted and adjusted incidence rates and examined trends by histology, age, race and ethnicity, and geographic region using joinpoint regression. The hysterectomy-adjusted cervical cancer incidence rate from 2001-2019 was 16.7 per 100 000 women-34.6% higher than the unadjusted rate. After adjustment, incidence rates were higher by approximately 55% among Black women, 56% among those living in the East South Central division, and 90% among women aged 70-79 and ≥80 years. These findings underscore the importance of adjusting for hysterectomy prevalence to avoid underestimating cervical cancer incidence rates and masking disparities by age, race, and geographic region. This article is part of a Special Collection on Gynecological Cancers.

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.

Assessment of Racial Misclassification Among American Indian and Alaska Native Identity in Cancer Surveillance Data in the United States and Considerations for Oral Health: A Systematic Review

Introduction

Misclassification of American Indian and Alaska Native (AI/AN) peoples exists across various databases in research and clinical practice. Oral health is associated with cancer incidence and survival; however, misclassification adds another layer of complexity to understanding the impact of poor oral health. The objective of this literature review was to systematically evaluate and analyze publications focused on racial misclassification of AI/AN racial identities among cancer surveillance data.

Methods

The PRISMA Statement and the CONSIDER Statement were used for this systematic literature review. Studies involving the racial misclassification of AI/AN identity among cancer surveillance data were screened for eligibility. Data were analyzed in terms of the discussion of racial misclassification, methods to reduce this error, and the reporting of research involving Indigenous peoples.

Results

A total of 66 articles were included with publication years ranging from 1972 to 2022. A total of 55 (83%) of the 66 articles discussed racial misclassification. The most common method of addressing racial misclassification among these articles was linkage with the Indian Health Service or tribal clinic records (45 articles or 82%). The average number of CONSIDER checklist domains was three, with a range of zero to eight domains included. The domain most often identified was Prioritization (60), followed by Governance (47), Methodologies (31), Dissemination (27), Relationships (22), Participation (9), Capacity (9), and Analysis and Findings (8).

Conclusion

To ensure equitable representation of AI/AN communities, and thwart further oppression of minorities, specifically AI/AN peoples, is through accurate data collection and reporting processes.

Characterizing Cancer Burden in the American Indian Population in North Carolina

BACKGROUND

The American Indian (AI) population in North Carolina has limited access to the Indian Health Service. Consequently, cancer burden and disparities may differ from national estimates. We describe the AI cancer population and examine AI-White disparities in cancer incidence and mortality.

METHODS

We identified cancer cases diagnosed among adult AI and White populations between 2014 and 2018 from the North Carolina Central Cancer Registry. We estimated incidence and mortality rate ratios (IRR and MRR) by race. In addition, between the AI and White populations, we estimated the ratio of relative frequency differences [RRF, with 95% confidence limits (CL)] of clinical and sociodemographic characteristics. Finally, we evaluated the geographic distribution of incident diagnoses among AI populations.

RESULTS

Our analytic sample included 2,161 AI and 204,613 White individuals with cancer. Compared with the White population, the AI population was more likely to live in rural areas (48% vs. 25%; RRF, 1.89; 95% CL, 1.81-1.97) and to have Medicaid (18% vs. 7%; RRF, 2.49; 95% CL, 2.27-2.71). Among the AI population, the highest age-standardized incidence rates were female breast, followed by prostate and lung and bronchus. Liver cancer incidence was significantly higher among the AI population than White population (IRR, 1.27; 95% CL, 1.01-1.59). AI patients had higher mortality rates for prostate (MRR, 1.72; CL, 1.09-2.70), stomach (MRR, 1.82; 95% CL, 1.15-2.86), and liver (MRR, 1.70; 95% CL, 1.25-2.33) cancers compared with White patients.

CONCLUSIONS

To reduce prostate, stomach, and liver cancer disparities among AI populations in North Carolina, multi-modal interventions targeting risk factors and increasing screening and treatment are needed.

IMPACT

This study identifies cancer disparities that can inform targeted interventions to improve outcomes among AI populations in North Carolina.

American Cancer Society's report on the status of cancer disparities in the United States, 2023

In 2021, the American Cancer Society published its first biennial report on the status of cancer disparities in the United States. In this second report, the authors provide updated data on racial, ethnic, socioeconomic (educational attainment as a marker), and geographic (metropolitan status) disparities in cancer occurrence and outcomes and contributing factors to these disparities in the country. The authors also review programs that have reduced cancer disparities and provide policy recommendations to further mitigate these inequalities. There are substantial variations in risk factors, stage at diagnosis, receipt of care, survival, and mortality for many cancers by race/ethnicity, educational attainment, and metropolitan status. During 2016 through 2020, Black and American Indian/Alaska Native people continued to bear a disproportionately higher burden of cancer deaths, both overall and from major cancers. By educational attainment, overall cancer mortality rates were about 1.6-2.8 times higher in individuals with ≤12 years of education than in those with ≥16 years of education among Black and White men and women. These disparities by educational attainment within each race were considerably larger than the Black-White disparities in overall cancer mortality within each educational attainment, ranging from 1.03 to 1.5 times higher among Black people, suggesting a major role for socioeconomic status disparities in racial disparities in cancer mortality given the disproportionally larger representation of Black people in lower socioeconomic status groups. Of note, the largest Black-White disparities in overall cancer mortality were among those who had ≥16 years of education. By area of residence, mortality from all cancer and from leading causes of cancer death were substantially higher in nonmetropolitan areas than in large metropolitan areas. For colorectal cancer, for example, mortality rates in nonmetropolitan areas versus large metropolitan areas were 23% higher among males and 21% higher among females. By age group, the racial and geographic disparities in cancer mortality were greater among individuals younger than 65 years than among those aged 65 years and older. Many of the observed racial, socioeconomic, and geographic disparities in cancer mortality align with disparities in exposure to risk factors and access to cancer prevention, early detection, and treatment, which are largely rooted in fundamental inequities in social determinants of health. Equitable policies at all levels of government, broad interdisciplinary engagement to address these inequities, and equitable implementation of evidence-based interventions, such as increasing health insurance coverage, are needed to reduce cancer disparities.

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.

Misracialization of Indigenous people in population health and mortality studies: a scoping review to establish promising practices

Indigenous people are often misracialized as other racial or ethnic identities in population health research. This misclassification leads to underestimation of Indigenous-specific mortality and health metrics, and subsequently, inadequate resource allocation. In recognition of this problem, investigators around the world have devised analytic methods to address racial misclassification of Indigenous people. We carried out a scoping review based on searches in PubMed, Web of Science, and the Native Health Database for empirical studies published after 2000 that include Indigenous-specific estimates of health or mortality and that take analytic steps to rectify racial misclassification of Indigenous people. We then considered the weaknesses and strengths of implemented analytic approaches, with a focus on methods used in the US context. To do this, we extracted information from 97 articles and compared the analytic approaches used. The most common approach to address Indigenous misclassification is to use data linkage; other methods include geographic restriction to areas where misclassification is less common, exclusion of some subgroups, imputation, aggregation, and electronic health record abstraction. We identified 4 primary limitations of these approaches: (1) combining data sources that use inconsistent processes and/or sources of race and ethnicity information; (2) conflating race, ethnicity, and nationality; (3) applying insufficient algorithms to bridge, impute, or link race and ethnicity information; and (4) assuming the hyperlocality of Indigenous people. Although there is no perfect solution to the issue of Indigenous misclassification in population-based studies, a review of this literature provided information on promising practices to consider.

Social vulnerability and lung malignancy mortality

INTRODUCTION

Lung cancer is a major cause of death in the United States. Social determinants of health (SDOH) are important factors that impact the treatment and prognosis of lung cancer. The social vulnerability index (SVI) is a validated measure of SDOH. This cross-sectional study aimed to investigate the impact of the SVI on lung cancer mortality using descriptive epidemiology.

METHODS

Mortality data for lung malignancies from 2014 to 2018 was obtained from the CDC database and was age-adjusted and standardized to the population in the year 2000. The SVI for the same years was obtained from the CDC Agency for Toxic Substances and Disease Registry database. Age-adjusted mortality rates (AAMR) were estimated for each SVI quartile (SVI-Q) and demographic subgroup.

RESULTS

We found that counties in SVI-Q4 (most vulnerable) had a higher cumulative AAMR compared to counties in SVI-Q1 (least vulnerable), accounting for a 4.48 excess death rate per 100,000 person-years. AAMR among males in SVI-Q4 was higher compared to SVI-Q1, accounting for a 9.96 excess death rate per 100,000 person-years, whereas no mortality differences were observed for female populations between SVI-Q4 and SVI-Q1. AAMR in SVI-Q4 was higher for both Hispanic and non-Hispanic populations, except for American Indian/Alaska Native populations. Similar trends were observed in both metropolitan and non-metropolitan counties.

CONCLUSION

Our study suggests that the SVI may play a significant role in lung cancer mortality and highlights the need for interventions targeting vulnerable populations to improve outcomes.

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.

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.

Prostate cancer disparities among American Indians and Alaskan Natives in the United States

BACKGROUND

Americans Indians and Alaska Natives face disparities in cancer care with lower rates of screening, limited treatment access, and worse survival. Prostate cancer treatment access and patterns of care remain unknown.

METHODS

We used Surveillance, Epidemiology, and End Results data to compare incidence, primary treatment, and cancer-specific mortality across American Indian and Alaska Native, Asian and Pacific Islander, Black, and White patients. Baseline characteristics included prostate-specific antigen (PSA), Gleason score (GS), tumor stage, 9-level Cancer of the Prostate Risk Assessment risk score, county characteristics, and health-care provider density. Primary outcomes were first definitive treatment and prostate cancer-specific mortality (PCSM).

RESULTS

American Indian and Alaska Native patients were more frequently diagnosed with higher PSA, GS greater than or equal or 8, stage greater than or equal to cT3, high-risk disease overall (Cancer of the Prostate Risk Assessment risk score ≥ 6), and metastases at diagnosis than any other group. Adjusting for age, PSA, GS, and clinical stage, American Indian or Alaska Native patients with localized prostate cancer were more likely to undergo external beam radiation than radical prostatectomy and had the highest rates of no documented treatment. Five-year PCSM was higher among American Indian and Alaska Natives than any other racial group. However, after multivariable adjustment accounting for clinical and pathologic factors, county-level demographics, and provider density, American Indian and Alaska Native patient PCSM hazards were no different than those of White patients.

CONCLUSIONS

American Indian or Alaska Native patients have more advanced prostate cancer, lower rates of definitive treatment, higher mortality, and reside in areas of less specialty care. Disparities in access appear to account for excess risks of PCSM. Focused health policy interventions are needed to address these disparities.

Cancer statistics for American Indian and Alaska Native individuals, 2022: Including increasing disparities in early onset colorectal cancer

American Indian and Alaska Native (AIAN) individuals are diverse culturally and geographically but share a high prevalence of chronic illness, largely because of obstacles to high-quality health care. The authors comprehensively examined cancer incidence and mortality among non-Hispanic AIAN individuals, compared with non-Hispanic White individuals for context, using population-based data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries. Overall cancer rates among AIAN individuals were 2% higher than among White individuals for incidence (2014 through 2018, confined to Purchased/Referred Care Delivery Area counties to reduce racial misclassification) but 18% higher for mortality (2015 through 2019). However, disparities varied widely by cancer type and geographic region. For example, breast and prostate cancer mortality rates are 8% and 31% higher, respectively, in AIAN individuals than in White individuals despite lower incidence and the availability of early detection tests for these cancers. The burden among AIAN individuals is highest for infection-related cancers (liver, stomach, and cervix), for kidney cancer, and for colorectal cancer among indigenous Alaskans (91.3 vs. 35.5 cases per 100,000 for White Alaskans), who have the highest rates in the world. Steep increases for early onset colorectal cancer, from 18.8 cases per 100,000 Native Alaskans aged 20-49 years during 1998 through 2002 to 34.8 cases per 100,000 during 2014 through 2018, exacerbated this disparity. Death rates for infection-related cancers (liver, stomach, and cervix), as well as kidney cancer, were approximately two-fold higher among AIAN individuals compared with White individuals. These findings highlight the need for more effective strategies to reduce the prevalence of chronic oncogenic infections and improve access to high-quality cancer screening and treatment for AIAN individuals. Mitigating the disparate burden will require expanded financial support of tribal health care as well as increased collaboration and engagement with this marginalized population.

Variations in Age-Adjusted Prostate Cancer Incidence Rates by Race and Ethnicity After Changes in Prostate-Specific Antigen Screening Recommendation

IMPORTANCE

After publication of US Preventive Task Force Prostate-Specific Antigen (PSA) screening guidelines in 2008 and 2012, there have been documented associations with incidence and stage distributions of prostate cancer. It is unclear if these changes were temporary or differed by age or race and ethnicity.

OBJECTIVE

To assess the association of 2008 and 2012 PSA guidelines with prostate cancer incidence by age and race and ethnicity in the US.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study evaluated prostate cancer incidence from 2005 to 2018 in the US using data from the US Cancer Statistics public use database. Data were analyzed from August 2020 through June 2022.

MAIN OUTCOMES AND MEASURES

The primary outcome was the year when rates of prostate cancer incidence changed directionality by age and race and ethnicity. Age-adjusted incidence rates of prostate cancer and corresponding 95% CIs were created, followed by join point regression analysis to evaluate trends of age-adjusted incidence rates of prostate cancer by age, race, Hispanic ethnicity, and stage of diagnosis.

RESULTS

Among 2 944 387 men with prostate cancer, 2 869 943 (97.5%) men were aged 50 years and older. Men aged 50 years and older accounted for 185 476 of 191 533 Hispanic individuals (96.8%) and 2 684 467 of 2 752 854 non-Hispanic individuals (97.5%). Men aged 50 years and older accounted for 427 016 of 447 847 African American individuals (95.4%), 12 141 of 12 470 American Indian or Alaska Native individuals (97.4%), 61 126 of 62 159 Asian or Pacific Islander individuals (98.3%), and 2 294 171 of 2 344 392 White individuals (97.9%). Men with unknown race (77 519 men) were excluded from the analysis. A decrease in age-adjusted rate of prostate cancer after the 2008 guideline change was observed in all age groups by race and ethnicity. For example, among African American men ages 65 to 74 years, 10 784 of 807 080 men (1.34%) had a prostate cancer diagnosis in 2007 vs 10 714 of 835 548 men in 2008 (1.28%). The mean annual age-adjusted incidence rates of prostate cancer per 100 000 men were 157.7 men (95% CI, 157.4-158.0 men) in 2005 to 2008 and 131.9 men (95% CI, 131.6-132.2 men) in 2009 to 2012. The number of inflections and annual percent changes (APCs) for segments separated by inflections varied by age, race, and Hispanic ethnicity. For men ages 65 to 74 years, the APC was -6.53 (95% CI, -9.28 to -3.69) for 2009 to 2014 among African American men (2 join points), -5.96 (95% CI, -6.84 to -5.07) for 2007 to 2018 among American Indian or Alaska Native men (1 join point), -6.52 (95% CI, -9.22 to -3.74) for 2007 to 2014 among Asian or Pacific Islander men (2 join points), -7.92 (95% CI, -11.36 to -4.35) for 2009 to 2014 among Hispanic men (2 join points), and -7.02 (95% CI, -9.41 to -4.57) for 2007 to 2014 among White men (2 join points).‬‬‬‬‬‬‬‬.

CONCLUSIONS AND RELEVANCE

In this study, men in different age, race, and ethnicity groups had different APC patterns after 2008 and 2012 PSA screening guideline changes. These findings may provide important data on the timing and durations of changes in cancer diagnoses that are associated with changes in PSA screening recommendations and may be valuable for targeted strategies to reduce regional- and distant-staged cancers.

Social Determinants of Cancer Risk Among American Indian and Alaska Native Populations: An Evidence Review and Map

Objectives:

To explore current literature on social determinants of health (SDOH) and cancer among American Indian and Alaska Native (AI/AN) populations.

Methods:

We searched Ovid MEDLINE^®, CINAHL, and PsycINFO databases for articles published during 2000 to 2020, which included terms for SDOH and cancer occurrence in AI/AN populations. We derived the data extraction elements from the PROGRESS-Plus framework. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-Equity extension guided the evidence map.

Results:

From 2180 screened articles, 297 were included. Most were observational (93.9%), employed a cross-sectional design (83.2%), were categorized as cancer occurrence and surveillance research (62%), and included no cancer-related risk factors (70.7%). Race, gender, and place were the most frequently included PROGRESS-Plus categories. Religion, relationship features, and characteristics of discrimination were least common. Only 12% of articles mentioned historical/current trauma or historical context.

Conclusions:

Gaps exist in our understanding of SDOH as drivers of cancer disparities in AI/AN populations. Future studies in health equity science may incorporate historical and cultural factors into SDOH frameworks tailored for AI/AN populations.

Health Disparities in Cancer Among American Indians and Alaska Natives

American Indians and Alaska Natives (AI/AN) are underserved populations who suffer from several health disparities, 1 of which is cancer. Malignancies, especially cancers of the breast, liver, and lung, are common causes of death in this population. Health care disparities in this population include more limited access to diagnostic radiology because of geographic and/or health system limitations. Early detection of these cancers may be enabled by improving patient and physician access to medical imaging. Awareness by the radiology community of the cancer disparities among this population is needed to support research targeted to this specific ethnic group and to support outreach efforts to provide more imaging opportunities. Providing greater access to imaging facilities will also improve patient compliance with screening recommendations, ultimately improving mortality in these populations.

Linking the Cherokee Nation Cancer Registry With Electronic Medical Records: A Tribal-Academic Center Partnership

The Cherokee Nation Cancer Registry (CNCR) is the only tribally operated Surveillance, Epidemiology, and End Results program registry. As registries, including the CNCR, lack detailed data characterizing health behavior or comorbidity, we aimed to enrich the CNCR by linking it with Cherokee Nation's electronic medical record (EMR). We describe the process of a tribal-academic partnership and linking records between the CNCR and the EMR for American Indian people diagnosed with cancer from 2015 to 2020. Prior to data linkage, our team worked with the Cherokee Nation Governance Board and Institutional Review Board to ensure tribal data sovereignty was maintained. While not all persons in the CNCR receive health care at Cherokee Nation, 63% linked with an EMR. We observed differences (P < .001) between cancer site, year at diagnosis, age at diagnosis, and gender by EMR linkage status. Once we further validate linkages and assess data completeness, we will evaluate relationships between behavioral risk factors, comorbidities, and cancer outcomes.

Kidney Cancer Incidence and Mortality Disparities Involving American Indians/Alaska Natives: An Analysis of the Oklahoma Central Cancer Registry (OCCR)

Purpose

This cohort study describes the differences in kidney cancer age-adjusted incidence and mortality rates between American Indians/Alaskan Natives (AI/ANs) and Whites in Oklahoma. Additionally, rates for the U.S. are updated to establish an epidemiological comparison between Oklahoma and the rest of the country.

Materials and Methods

Kidney cancer age-adjusted incidence and mortality rates for Oklahoma were gathered using the Oklahoma Central Cancer Registry since 1999. National rates were obtained from the Center for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research database between 1997 and 2017. Rate ratios were used to compare incidence and mortality rates for AI/ANs and Whites within Oklahoma as well as the entire country. Joinpoint regression models were created to illustrate trends in kidney cancer incidence and mortality.

Results

The age-adjusted incidence rate of kidney cancer in Oklahoma for AI/ANs and Whites was 32.3 and 15.8 per 100,000, respectively, for an incidence rate ratio of 2.04. The national incidence rate ratio was 0.89. The age-adjusted mortality rate in Oklahoma for AI/ANs and Whites was 9.78 and 4.98 per 100,000, respectively, for a mortality rate ratio of 1.98. Oklahomans, irrespective of race, fare worse in terms of kidney cancer mortality compared to the rest of the country.

Conclusions

In Oklahoma, AI/ANs are more likely than Whites to have a kidney cancer diagnosis. AI/ANs are twice as likely to die from kidney cancer than Whites in Oklahoma. AI/AN populations in certain states may benefit from kidney cancer early screening initiatives.

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.

The Black Panther, Masculinity Barriers to Medical Care, and Colorectal Cancer Screening Intention Among Unscreened American Indian/Alaska Native, Black, and White Men

Objective

To determine if masculinity barriers to medical care and the death from colorectal cancer (CRC) of actor Chadwick Boseman (The Black Panther) influenced CRC early-detection screening intent among unscreened American Indian/Alaska Native (AIAN) and Non-Hispanic-Black (Black) men compared with Non-Hispanic-White (White) men.

Methods

Using a consumer-panel, we surveyed U.S. men aged 18-75 years (N = 895) using the 24-item Masculinity Barriers to Medical Care (MBMC) scale. We calculated the median score to create binary exposures to evaluate associations with CRC screening intent and conducted multivariable logistic regression to evaluate independent associations stratified by race/ethnicity.

Results

Overall, Black respondents were most likely to have a high MBMC score (55%) compared to White (44%) and AIAN (51%) men (p = 0.043). AIAN men were least likely to report CRC screening intent (51.1%) compared with Black (68%) and White men (64%) (p < 0.001). Black men who reported the recent death of Chadwick Boseman increased their awareness of CRC were more likely (78%) to report intention to screen for CRC compared to those who did not (56%) (p < 0.001). Black men who exhibited more masculinity-related barriers to care were more likely to intend to screen for CRC (OR: 1.76, 95% CI: 0.98-3.16) than their counterparts, as were Black men who reported no impact of Boseman's death on their CRC awareness (aOR: 2.96, 95% CI: 1.13-7.67). Conversely, among AIAN men, those who exhibited more masculinity-related barriers to care were less likely to have CRC screening intent (aOR: 0.47, 95% CI: 0.27-0.82) compared with their counterparts.

Conclusions

Masculinity barriers to medical care play a significant role in intention to screen for CRC. While Black men were most likely to state that The Black Panther's death increased their awareness of CRC, it did not appear to modify the role of masculine barriers in CRC screening intention as expected. Further research is warranted to better understand how masculine barriers combined with celebrity-driven health-promotion interventions influence the uptake of early-detection screening for CRC.

Impact

Our study provides formative data to develop behavioral interventions focused on improving CRC screening completion among diverse men.

The Indian Health Service and American Indian/Alaska Native Health Outcomes

The Indian Health Service (IHS) has made huge strides in narrowing health disparities between American Indian and Alaska Native (AI/AN) populations and other racial and ethnic groups. Yet, health disparities experienced by AI/AN people persist, with deep historical roots combined with present-day challenges. Here we review the history of the IHS from colonization to the present-day system, highlight persistent disparities in AI/AN health and health care, and discuss six key present-day challenges: inadequate funding, limited human resources, challenges associated with transitioning services from federal to Tribal control through contracting and compacting, evolving federal and state programs, the need for culturally sensitive services, and the promise and challenges of health technology.

Indigenous health equity in health register ascertainment and data quality: a narrative review

Background

Health registers play an important role in monitoring distribution of disease and quality of care; however, benefit is limited if ascertainment (i.e., the process of finding and recruiting people on to a register) and data quality (i.e., the accuracy, completeness, reliability, relevance, and timeliness of data) are poor. Indigenous peoples experience significant health inequities globally, yet health data for, and about, Indigenous peoples is often of poor quality. This narrative review aimed to (i) identify perceived barriers for the ascertainment of Indigenous peoples on health registers, and (ii) collate strategies identified and used by health registers to support comprehensive ascertainment and high-quality data for Indigenous peoples.

Methods

A Kaupapa Māori theoretical framework was utilized to guide this work. Four electronic databases were systematically searched for original articles and screened for eligibility. Studies involving health registers with Indigenous population(s) identified were included if either ascertainment or data quality strategies were described. Data extraction focused on the reporting of research involving Indigenous peoples using the CONSIDER checklist domains, ascertainment, and data quality.

Results

Seventeen articles were included spanning publication between 1992 and 2020. Aspects of four of eight CONSIDER domains were identified to be included in the reporting of studies. Barriers to ascertainment were themed as relating to ‘ethnicity data collection and quality’, ‘systems and structures’, ‘health services/health professionals’, and ‘perceptions of individual and community-level barriers’. Strategies to support ascertainment were categorized as ‘collaboration’, ‘finding people’, and ‘recruitment processes’. Categorized strategies to support data quality were ‘collaboration’, ‘ethnicity data collection and quality’, ‘systems-level strategies’, and ‘health service/health professional-level strategies’.

Conclusions

Poor-quality data for Indigenous peoples in health registers prevents the achievement of health equity and exemplifies inaction in the face of need. When viewed through a critical structural determinants lens, there are visible gaps in the breadth of strategies, particularly relating to the inclusion of Indigenous peoples in health register and research governance, and actions to identify and address institutional racism. Indigenous led research, meaningful collaboration, and a sharing of knowledge and experiences between health registers is recommended to enable research and health registers that support Indigenous self-determination and health equity.

Masculinity Barriers to Ever Completing Colorectal Cancer Screening among American Indian/Alaska Native, Black, and White Men (Ages 45-75)

Disparities in colorectal cancer (CRC) mortality among White, Black, and American Indian/Alaska Native (AIAN) men are attributable to differences in early detection screening. Determining how masculinity barriers influence CRC screening completion is critical for cancer prevention and control. To determine whether masculinity barriers to medical care are associated with lower rates of ever completing CRC screening, a survey-based study was employed from December 2020-January 2021 among 435 White, Black, and AIAN men (aged 45-75) who resided in the US. Logistic regression models were fit to four Masculinity Barriers to Medical Care subscales predicting ever completing CRC screening. For all men, being strong was associated with 54% decreased odds of CRC screening completion (OR 0.46, 95% CI 0.23 to 0.94); each unit increase in negative attitudes toward medical professionals and exams decreased the odds of ever completing CRC screening by 57% (OR 0.43, 95% CI 0.21 to 0.86). Black men who scored higher on negativity toward medical professionals and exams had decreased odds of ever screening. Consideration of masculinity in future population-based and intervention research is critical for increasing men's participation in CRC screening, with more salience for Black men.

American Cancer Society's report on the status of cancer disparities in the United States, 2021

In this report, the authors provide comprehensive and up-to-date US data on disparities in cancer occurrence, major risk factors, and access to and utilization of preventive measures and screening by sociodemographic characteristics. They also review programs and resources that have reduced cancer disparities and provide policy recommendations to further mitigate these inequalities. The overall cancer death rate is 19% higher among Black males than among White males. Black females also have a 12% higher overall cancer death rate than their White counterparts despite having an 8% lower incidence rate. There are also substantial variations in death rates for specific cancer types and in stage at diagnosis, survival, exposure to risk factors, and receipt of preventive measures and screening by race/ethnicity, socioeconomic status, and geographic location. For example, kidney cancer death rates by sex among American Indian/Alaska Native people are ≥64% higher than the corresponding rates in each of the other racial/ethnic groups, and the 5-year relative survival for all cancers combined is 14% lower among residents of poorer counties than among residents of more affluent counties. Broad and equitable implementation of evidence-based interventions, such as increasing health insurance coverage through Medicaid expansion or other initiatives, could substantially reduce cancer disparities. However, progress will require not only equitable local, state, and federal policies but also broad interdisciplinary engagement to elevate and address fundamental social inequities and longstanding systemic racism.

Disparities in Breast-Conserving Therapy for Non-Hispanic American Indian/Alaska Native Women Compared with Non-Hispanic White Women

BACKGROUND

Little is known about the surgical patterns of American Indian/Alaska Native (AI/AN) breast cancer patients. The purpose of this study is to determine whether there are disparities in breast cancer surgery and radiation therapy between non-Hispanic AI/AN (NH-AI/AN) women and non-Hispanic White (NHW) women.

METHODS

Data from the National Program of Cancer Registries of the Centers for Disease Control and Surveillance, Epidemiology, and End Results were used for this cross-sectional study. Female patients with invasive breast cancer diagnosed 2010-2015 were stratified by race/ethnicity, surgical procedure, radiation, and region. Percentage distributions of mastectomy and lumpectomy were compared overall and by region and stage.

RESULTS

From 2010 to 2015 there were 3292 NH-AI/AN women and 165,225 NHW women diagnosed with breast cancer. For early stage (AJCC stage 1 and 2), NH-AI/AN women had overall significantly higher percentage of mastectomy (41% vs 34.4%, p < 0.001) and significantly lower percentage of lumpectomy (59% vs 65.6%) compared with NHW women, without significant differences in post-lumpectomy radiation (71% vs 70%). There were regional variations, notably in the Northern Plains, where the percentage of mastectomy for early-stage disease was 48.9% for NH-AI/AN women versus 35.9% for NHW women, and in Alaska with 47% for NH-AI/AN women versus 33.3% for NHW women (p < 0.001). There were no overall significant differences in type of surgery or radiation for late-stage disease between groups.

CONCLUSION

This is the first study to show disparities in surgical management of NH-AI/AN women with breast cancer. For early-stage disease, NH-AI/AN women undergo a higher percentage of mastectomy. Future clinical directions could focus on the factors that drive awareness, decision-making, and access to breast conservation.

Growing Disparity in the Incidence of Colorectal Cancer among Non-Hispanic American Indian and Alaska Native Populations-United States, 2013-2017

BACKGROUND

American Indian and Alaska Native (AI/AN) populations have experienced regional variation and disparities in colorectal cancer incidence rates.

METHODS

We examined colorectal cancer incidence (2013-2017) and colorectal cancer incidence trends (1999-2017) among AI/AN persons. Incidence data were linked to Indian Health Service enrollment records, and analyses were restricted to Purchased/Referred Care Delivery Areas. Incidence rates of colorectal cancer among AI/AN and White persons were analyzed in six geographic regions; Hispanic persons were excluded. Incidence trends were analyzed using linear modeling.

RESULTS

During 2013-2017, colorectal cancer incidence was 41% higher among AI/AN than among White persons. AI/AN incidence rates per 100,000 varied regionally from 34.4 in the East to 96.1 in Alaska. Compared with White persons, AI/AN persons had higher colorectal cancer incidence rates among all age strata and were more likely to have late-stage diagnoses. Incidence rate trends indicated significant increases among both AI/AN and White persons ages <50 years and among AI/AN persons ages 50-64 years. The colorectal cancer incidence rate trend increased among AI/AN persons in the Southwest.

CONCLUSIONS

The disparity of colorectal cancer incidence rates between AI/AN and White persons has widened since 2005-2009. AI/AN populations have higher colorectal cancer incidence compared with White populations, especially in the Alaska region.

IMPACT

Our finding of increased colorectal cancer incidence disparities suggests that enhanced screening efforts and culturally appropriate clinical and public health interventions are needed among AI/AN persons overall, and especially in regions and age groups in which colorectal cancer rates are increasing.

Cancer mortality in a population-based cohort of American Indians - The strong heart study

BACKGROUND

Cancer mortality among American Indian (AI) people varies widely, but factors associated with cancer mortality are infrequently assessed.

METHODS

Cancer deaths were identified from death certificate data for 3516 participants of the Strong Heart Study, a population-based cohort study of AI adults ages 45-74 years in Arizona, Oklahoma, and North and South Dakota. Cancer mortality was calculated by age, sex and region. Cox proportional hazards model was used to assess independent associations between baseline factors in 1989 and cancer death by 2010.

RESULTS

After a median follow-up of 15.3 years, the cancer death rate per 1000 person-years was 6.33 (95 % CI 5.67-7.04). Cancer mortality was highest among men in North/South Dakota (8.18; 95 % CI 6.46-10.23) and lowest among women in Arizona (4.57; 95 % CI 2.87-6.92). Factors independently associated with increased cancer mortality included age, current or former smoking, waist circumference, albuminuria, urinary cadmium, and prior cancer history. Factors associated with decreased cancer mortality included Oklahoma compared to Dakota residence, higher body mass index and total cholesterol. Sex was not associated with cancer mortality. Lung cancer was the leading cause of cancer mortality overall (1.56/1000 person-years), but no lung cancer deaths occurred among Arizona participants. Mortality from unspecified cancer was relatively high (0.48/100 person-years; 95 % CI 0.32-0.71).

CONCLUSIONS

Regional variation in AI cancer mortality persisted despite adjustment for individual risk factors. Mortality from unspecified cancer was high. Better understanding of regional differences in cancer mortality, and better classification of cancer deaths, will help healthcare programs address cancer in AI communities.

Racial Differences in Incident Genitourinary Cancer Cases Captured in the National Cancer Database

Background and Objectives: The National Cancer Database (NCDB) captures nearly 70% of all new cancer diagnoses in the United States, but there exists significant variation in this capture rate based on primary tumor location and other patient demographic factors. Prostate cancer has the lowest coverage rate of all major cancers, and other genitourinary malignancies likewise fall below the average NCDB case coverage rate. We aimed to explore NCDB coverage rates for patients with genitourinary cancers as a function of race. Materials and Methods: We compared the incidence of cancer cases in the NCDB with contemporary United States Cancer Statistics data. Results: Across all malignancies, American Indian/Alaskan Natives subjects demonstrated the lowest capture rates, and Asian/Pacific Islander subjects exhibited the second-lowest capture rates. Between White and Black subjects, capture rates were significantly higher for White subjects overall and for prostate cancer and kidney cancer in White males, but significantly higher for bladder cancer in Black versus White females. No significant differences were observed in coverage rates for kidney cancer in females, bladder cancer in males, penile cancer, or testicular cancer in White versus Black patients. Conclusions: Differential access to Commission on Cancer-accredited treatment facilities for racial minorities with genitourinary cancer constitutes a unique avenue for health equity research.

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.

Pediatric Cancers among Alaska Native People

OBJECTIVE

To evaluate the descriptive epidemiology of pediatric cancers among Alaska Native 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, 3rd 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 12-month and 5-year cause-specific survival, and examined differences over the time period, adjusted for age, sex, and ICCC-3 site.

RESULTS

Incidence rates of pediatric cancers increased between 1969 and 1996 (n = 134) and 1997 and 2016 (n = 186) among Alaska Native people, from 139.8 in 1 000 000 (95% CI, 116.99-165.7) to 197.54 in 1 000 000 (95% CI, 170.1-228.1). Distribution of ICCC-3 sites differed between time periods (P < .0001). Finally, cancer survival was high; the 12-month survival probability from all ICCC-3 sites combined was 0.88 (95% CI, 0.84-0.92) and the 5-year survival probability was 0.76 (95% CI, 0.70-0.81) for 1969-2016. After adjusting for age, sex, and ICCC-3 site, we observed a 57% decrease in the risk of death when comparing Alaska Native pediatric cancer cases diagnosed in 1997-2016 with those diagnosed in 1969-1996.

CONCLUSIONS

This information will be of value for our understanding of pediatric cancers among Indigenous peoples of the US, and will also be informative for clinicians providing care to this population.

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.

Racial Misclassification in Mortality Records Among American Indians/Alaska Natives in Oklahoma From 1991 to 2015

OBJECTIVE

The primary purpose of this study was to compare age-adjusted mortality rates before and after linkage with Indian Health Service records, adjusting for racial misclassification. We focused on differences in racial misclassification by gender, age, geographic differences, substate planning districts, and cause of death. Our secondary purpose was to evaluate time trends in misclassification from 1991 to 2015.

DESIGN

Retrospective, descriptive study.

SETTING

Oklahoma.

PARTICIPANTS

Persons contained in the Oklahoma State Health Department Vital Records.

MAIN OUTCOME MEASURES

To evaluate the age-adjusted mortality ratio pre- and post-Indian Health Service record linkage (misclassification rate ratio) and to evaluate the overall trend of racial misclassification on mortality records measured through annual percent change (APC) and average annual percent change (AAPC).

RESULTS

We identified 2 stable trends of racial misclassification upon death for American Indians/Alaska Natives (AI/ANs) from 1991 to 2001 (APC: -0.2%; 95% confidence interval: -1.4% to 1.0%) and from 2001 to 2005 (APC: -6.9%; 95% confidence interval: -13.7% to 0.4%). However, the trend identified from 2005 to 2015 decreased significantly (APC: -1.4%; 95% confidence interval: -2.5% to -0.2%). For the last 5 years available (2011-2015), the racial misclassification adjustment resulted in higher mortality rates for AI/ANs reflecting an increase from 1008 per 100 000 to 1305 per 100 000 with the linkage process. There were an estimated 3939 AI/ANs in Oklahoma who were misclassified as another race upon death in those 5 years, resulting in an underestimation of actual AI/AN deaths by nearly 29%.

CONCLUSIONS

An important result of this study is that misclassification is improving; however, this effort needs to be maintained and further improved. Continued linkage efforts and public access to linked data are essential throughout the United States to better understand the burden of disease in the AI/AN population.

Trends in Cancer Incidence Among American Indians and Alaska Natives and Non-Hispanic Whites in the United States, 1999-2015

BACKGROUND

Female breast, prostate, lung, and colorectal cancers are the leading incident cancers among American Indian and Alaska Native (AI/AN) and non-Hispanic White (NHW) persons in the United States. To understand racial differences, we assessed incidence rates, analyzed trends, and examined geographic variation in incidence by Indian Health Service regions.

METHODS

To assess differences in incidence, we used age-adjusted incidence rates to calculate rate ratios (RRs) and 95% confidence intervals (CIs). Using joinpoint regression, we analyzed incidence trends over time for the four leading cancers from 1999 to 2015.

RESULTS

For all four cancers, overall and age-specific incidence rates were lower among AI/ANs than NHWs. By Indian Health Service regions, incidence rates for lung cancer were higher among AI/ANs than NHWs in Alaska (RR: 1.46; 95% CI: 1.37, 1.56) and Northern (RR: 1.29; 95% CI: 1.25, 1.33) and Southern (RR: 1.06; 95% CI: 1.03, 1.09) Plains. Similarly, colorectal cancer incidence rates were higher in AI/ANs than NHWs in Alaska (RR: 2.29; 95% CI: 2.14, 2.45) and Northern (RR: 1.04; 95% CI: 1.00, 1.09) and Southern (RR: 1.11; 95% CI: 1.07, 1.15) Plains. Also, AI/AN women in Alaska had a higher incidence rate for breast cancer than NHW women (RR: 1.05; 95% CI: 1.05, 1.20). From 1999 to 2015, incidence rates for all four cancers decreased in NHWs, but only rates for prostate (average annual percent change: -4.70) and colorectal (average annual percent change: -1.80) cancers decreased considerably in AI/ANs.

CONCLUSION

Findings from this study highlight the racial and regional differences in cancer incidence.

Collection and Reporting of Indigenous Status Information in Cancer Registries Around the World

PURPOSE

Worldwide, Indigenous people often have disproportionally worse health and lower life expectancy than their non-Indigenous counterparts. Despite the impact of cancer on life expectancy, little is known about the burden of cancer for Indigenous people primarily because of the paucity of data. We investigated the collection and reporting of Indigenous status information among a global sample of population-based cancer registries (PBCRs).

PARTICIPANTS AND METHODS

An online survey was e-mailed to eligible registries using set inclusion criteria. Respondents were asked questions on the collection, reporting, and quality assessment of Indigenous status in their registers.

RESULTS

Eighty-three PBCRs from 25 countries were included. Of these, 66% reported that their registry collected Indigenous status data, although the quality of this variable had been assessed in less than half in terms of completeness (38%) and accuracy (47%). Two thirds of PBCRs who collected Indigenous status data (67%), from nine of 25 countries responded that cancer statistics for Indigenous people were reported using registry data. Key barriers to the collection of Indigenous status information included the lack of data collection at the point of care (79%), lack of transfer of Indigenous status to the cancer registry (46%), inadequate information systems (43%), and legislative limitations (32%). Important variations existed among world regions, although the lack of Indigenous status data collection at the point of care was commonly reported across all regions.

CONCLUSION

High-quality data collection is lacking for Indigenous peoples in many countries. To ensure the design and implementation of cancer control activities required to reduce disparities for Indigenous populations, health information systems, including cancer registries, need to be strengthened, and this must be done in dialogue with Indigenous leaders.

Andersen's Behavioral Model to Identify Correlates of Breast Cancer Screening Behaviors among Indigenous Women

This study examined predictive models of utilization of mammograms among Indigenous women adapting Andersen's behavioral model. Using a sample of 285 Indigenous women residing in South Dakota, nested logistic regression analyses were conducted to assess predisposing (age and marital status), need (personal and family cancer history), and enabling factors (education, monthly household income, mammogram screening awareness, breast cancer knowledge, self-rated health, and cultural practice to breast cancer screening). Results indicated that only 55.5% of participants reported having had a breast cancer screening within the past 2 years. After controlling for predisposing and need factors, higher education, greater awareness of mammogram, and higher utilization of traditional Native American approaches were significant predictors of mammogram uptake. The results provide important implications for intervention strategies aimed at improving breast cancer screening and service use among Indigenous women.

Disparities in Cancer Incidence and Trends among American Indians and Alaska Natives in the United States, 2010-2015

BACKGROUND

Cancer incidence rates for American Indian and Alaska Native (AI/AN) populations vary by geographic region in the United States. The purpose of this study is to examine cancer incidence rates and trends in the AI/AN population compared with the non-Hispanic white population in the United States for the years 2010 to 2015.

METHODS

Cases diagnosed during 2010 to 2015 were identified from population-based cancer registries and linked with the Indian Health Service (IHS) patient registration databases to describe cancer incidence rates in non-Hispanic AI/AN persons compared with non-Hispanic whites (whites) living in IHS purchased/referred care delivery area counties. Age-adjusted rates were calculated for the 15 most common cancer sites, expressed per 100,000 per year. Incidence rates are presented overall as well as by region. Trends were estimated using joinpoint regression analyses.

RESULTS

Lung and colorectal cancer incidence rates were nearly 20% to 2.5 times higher in AI/AN males and nearly 20% to nearly 3 times higher in AI/AN females compared with whites in the Northern Plains, Southern Plains, Pacific Coast, and Alaska. Cancers of the liver, kidney, and stomach were significantly higher in the AI/AN compared with the white population in all regions. We observed more significant decreases in cancer incidence rates in the white population compared with the AI/AN population.

CONCLUSIONS

Findings demonstrate the importance of examining cancer disparities between AI/AN and white populations. Disparities have widened for lung, female breast, and liver cancers.

IMPACT

These findings highlight opportunities for targeted public health interventions to reduce AI/AN cancer incidence.

Using Tribal Data Linkages to Improve the Quality of American Indian Cancer Data in Michigan

This study examines the extent to which data linkages between Indian Health Service, tribal data, and cancer registries affect cancer incidence rates among American Indians/Alaska Natives (AI/ANs) in Michigan. The incidence of tobacco- and alcohol-associated cancers for 1995-2012 was analyzed to compare rates of the Upper Peninsula (UP) and Lower Peninsula (LP) in Michigan and among AI/ANs and non-Hispanic Whites (NHWs). Complete linkage resulted in 1,352 additional AI/AN cases; 141 cases were linked via IHS records alone, while 373 were linked via tribal records alone; 838 were linked through both IHS and tribal records. Age-adjusted incidence rates for AI/ANs increased from 214.39 per 100,000 to 405.41 per 100,000, similar to that of NHWs after complete linkage (421.46 per 100,000). In the UP, AI/ANs had age-adjusted incidence rates 1.67 times higher than NHWs (596.69 per 100,000 vs. 356.32 per 100,000 respectively). This study indicates a substantial number of AI/AN cancer cases remain misclassified in Michigan.

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.

Annual Report to the Nation on the Status of Cancer, part I: National cancer statistics

BACKGROUND

The American Cancer Society (ACS), the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR) collaborate to provide annual updates on cancer occurrence and trends in the United States.

METHODS

Incidence data were obtained from the CDC-funded and NCI-funded population-based cancer registry programs and compiled by NAACCR. Data on cancer deaths were obtained from the National Center for Health Statistics National Vital Statistics System. Trends in age-standardized incidence and death rates for all cancers combined and for the leading cancer types by sex, race, and ethnicity were estimated by joinpoint analysis and expressed as the annual percent change. Stage distribution and 5-year survival by stage at diagnosis were calculated for breast cancer, colon and rectum (colorectal) cancer, lung and bronchus cancer, and melanoma of the skin.

RESULTS

Overall cancer incidence rates from 2008 to 2014 decreased by 2.2% per year among men but were stable among women. Overall cancer death rates from 1999 to 2015 decreased by 1.8% per year among men and by 1.4% per year among women. Among men, incidence rates during the most recent 5-year period (2010-2014) decreased for 7 of the 17 most common cancer types, and death rates (2011-2015) decreased for 11 of the 18 most common types. Among women, incidence rates declined for 7 of the 18 most common cancers, and death rates declined for 14 of the 20 most common cancers. Death rates decreased for cancer sites, including lung and bronchus (men and women), colorectal (men and women), female breast, and prostate. Death rates increased for cancers of the liver (men and women); pancreas (men and women); brain and other nervous system (men and women); oral cavity and pharynx (men only); soft tissue, including heart (men only); nonmelanoma skin (men only); and uterus. Incidence and death rates were higher among men than among women for all racial and ethnic groups. For all cancer sites combined, black men and white women had the highest incidence rates compared with other racial groups, and black men and black women had the highest death rates compared with other racial groups. Non-Hispanic men and women had higher incidence and mortality rates than those of Hispanic ethnicity. Five-year survival for cases diagnosed from 2007 through 2013 ranged from 100% (stage I) to 26.5% (stage IV) for female breast cancer, from 88.1% (stage I) to 12.6% (stage IV) for colorectal cancer, from 55.1% (stage I) to 4.2% (stage IV) for lung and bronchus cancer, and from 99.5% (stage I) to 16% (stage IV) for melanoma of the skin. Among children, overall cancer incidence rates increased by 0.8% per year from 2010 to 2014, and overall cancer death rates decreased by 1.5% per year from 2011 to 2015.

CONCLUSIONS

For all cancer sites combined, cancer incidence rates decreased among men but were stable among women. Overall, there continue to be significant declines in cancer death rates among both men and women. Differences in rates and trends by race and ethnic group remain. Progress in reducing cancer mortality has not occurred for all sites. Examining stage distribution and 5-year survival by stage highlights the potential benefits associated with early detection and treatment. Cancer 2018;124:2785-2800. © 2018 American Cancer Society.

Measuring cancer in indigenous populations

It is estimated that there are 370 million indigenous peoples in 90 countries globally. Indigenous peoples generally face substantial disadvantage and poorer health status compared with nonindigenous peoples. Population-level cancer surveillance provides data to set priorities, inform policies, and monitor progress over time. Measuring the cancer burden of vulnerable subpopulations, particularly indigenous peoples, is problematic. There are a number of practical and methodological issues potentially resulting in substantial underestimation of cancer incidence and mortality rates, and biased survival rates, among indigenous peoples. This, in turn, may result in a deprioritization of cancer-related programs and policies among these populations. This commentary describes key issues relating to cancer surveillance among indigenous populations including 1) suboptimal identification of indigenous populations, 2) numerator-denominator bias, 3) problems with data linkage in survival analysis, and 4) statistical analytic considerations. We suggest solutions that can be implemented to strengthen the visibility of indigenous peoples around the world. These include acknowledgment of the central importance of full engagement of indigenous peoples with all data-related processes, encouraging the use of indigenous identifiers in national and regional data sets and mitigation and/or careful assessment of biases inherent in cancer surveillance methods for indigenous peoples.

The history and use of cancer registry data by public health cancer control programs in the United States

Because cancer registry data provide a census of cancer cases, registry data can be used to: 1) define and monitor cancer incidence at the local, state, and national levels; 2) investigate patterns of cancer treatment; and 3) evaluate the effectiveness of public health efforts to prevent cancer cases and improve cancer survival. The purpose of this article is to provide a broad overview of the history of cancer surveillance programs in the United States, and illustrate the expanding ways in which cancer surveillance data are being made available and contributing to cancer control programs. The article describes the building of the cancer registry infrastructure and the successful coordination of efforts among the 2 federal agencies that support cancer registry programs, the Centers for Disease Control and Prevention and the National Cancer Institute, and the North American Association of Central Cancer Registries. The major US cancer control programs also are described, including the National Comprehensive Cancer Control Program, the National Breast and Cervical Cancer Early Detection Program, and the Colorectal Cancer Control Program. This overview illustrates how cancer registry data can inform public health actions to reduce disparities in cancer outcomes and may be instructional for a variety of cancer control professionals in the United States and in other countries. Cancer 2017;123:4969-76. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Capture and coding of industry and occupation measures: Findings from eight National Program of Cancer Registries states

BACKGROUND

Although data on industry and occupation (I&O) are important for understanding cancer risks, obtaining standardized data is challenging. This study describes the capture of specific I&O text and the ability of a web-based tool to translate text into standardized codes.

METHODS

Data on 62 525 cancers cases received from eight National Program of Cancer Registries (NPCR) states were submitted to a web-based coding tool developed by the National Institute for Occupational Safety and Health for translation into standardized I&O codes. We determined the percentage of sufficiently analyzable codes generated by the tool.

RESULTS

Using the web-based coding tool on data obtained from chart abstraction, the NPCR cancer registries achieved between 48% and 75% autocoding, but only 12-57% sufficiently analyzable codes.

CONCLUSIONS

The ability to explore associations between work-related exposures and cancer is limited by current capture and coding of I&O data. Increased training of providers and registrars, as well as software enhancements, will improve the utility of I&O data.

Annual Report to the Nation on the Status of Cancer, 1975-2014, Featuring Survival

Background: The American Cancer Society (ACS), the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR) collaborate to provide annual updates on cancer occurrence and trends in the United States. This Annual Report highlights survival rates. Methods: Data were from the CDC- and NCI-funded population-based cancer registry programs and compiled by NAACCR. Trends in age-standardized incidence and death rates for all cancers combined and for the leading cancer types by sex were estimated by joinpoint analysis and expressed as annual percent change. We used relative survival ratios and adjusted relative risk of death after a diagnosis of cancer (hazard ratios [HRs]) using Cox regression model to examine changes or differences in survival over time and by sociodemographic factors.

Results: Overall cancer death rates from 2010 to 2014 decreased by 1.8% (95% confidence interval [CI] = –1.8 to –1.8) per year in men, by 1.4% (95% CI = –1.4 to –1.3) per year in women, and by 1.6% (95% CI = –2.0 to –1.3) per year in children. Death rates decreased for 11 of the 16 most common cancer types in men and for 13 of the 18 most common cancer types in women, including lung, colorectal, female breast, and prostate, whereas death rates increased for liver (men and women), pancreas (men), brain (men), and uterine cancers. In contrast, overall incidence rates from 2009 to 2013 decreased by 2.3% (95% CI = –3.1 to –1.4) per year in men but stabilized in women. For several but not all cancer types, survival statistically significantly improved over time for both early and late-stage diseases. Between 1975 and 1977, and 2006 and 2012, for example, five-year relative survival for distant-stage disease statistically significantly increased from 18.7% (95% CI = 16.9% to 20.6%) to 33.6% (95% CI = 32.2% to 35.0%) for female breast cancer but not for liver cancer (from 1.1%, 95% CI = 0.3% to 2.9%, to 2.3%, 95% CI = 1.6% to 3.2%). Survival varied by race/ethnicity and state. For example, the adjusted relative risk of death for all cancers combined was 33% (HR = 1.33, 95% CI = 1.32 to 1.34) higher in non-Hispanic blacks and 51% (HR = 1.51, 95% CI = 1.46 to 1.56) higher in non-Hispanic American Indian/Alaska Native compared with non-Hispanic whites.

Conclusions: Cancer death rates continue to decrease in the United States. However, progress in reducing death rates and improving survival is limited for several cancer types, underscoring the need for intensified efforts to discover new strategies for prevention, early detection, and treatment and to apply proven preventive measures broadly and equitably.

Text message reminders increased colorectal cancer screening in a randomized trial with Alaska Native and American Indian people

BACKGROUND

Alaska Native and American Indian people (AN/AIs) have a high incidence of colorectal cancer (CRC) and CRC-related mortality. Screening can prevent death from CRC, but screening rates are low in racially and ethnically diverse populations. The authors conducted a randomized controlled trial using text messaging to increase CRC screening among unscreened AN/AIs in a tribal health care system in Anchorage, Alaska.

METHODS

The intervention entailed up to 3 text messages sent 1 month apart. The authors randomized 2386 AN/AIs aged 40 to 75 years who were eligible for CRC screening to the intervention or usual-care control conditions. Screening status was ascertained from electronic health records 3 months and 6 months after the last text message. Hazard ratios (HRs) were estimated to evaluate the effectiveness of the intervention, stratified by age and sex.

RESULTS

The intervention increased CRC screening for AN/AIs aged 50 to 75 years (HR, 1.42; 95% confidence interval [95% CI], 0.97-2.09) and aged 40 to 49 years (HR, 1.24; 95% CI, 0.95-1.62). Within both age groups, the HRs were higher for women (HR, 1.69 [95% CI, 1.02-2.80] and HR, 1.37 [95% CI, 1.01-1.88]) compared with men (HR, 1.09 [95% CI, 0.59-1.99] and HR, 0.90 [95% CI, 0.54-1.53]). Interaction analysis yielded P values of .55 and .09, respectively, for age and sex.

CONCLUSIONS

A simple text messaging intervention was found to increase CRC screening rates in AN/AIs, a group with high CRC morbidity and mortality. Text messaging may be a cost-effective means of reducing CRC screening disparities in AN/AIs and other populations. Cancer 2017;123:1382-1389. © 2016 American Cancer Society.

Hospitalizations at Nonfederal Facilities for Lower Respiratory Tract Infection in American Indian and Alaska Native Children Younger than 5 Years of Age, 1997-2012

OBJECTIVES

To evaluate hospitalizations at nonfederal facilities for lower respiratory tract infection (LRTI) in American Indian/Alaska Native (AI/AN) children and to compare associated rates and risk factors in AI/AN children and white children.

STUDY DESIGN

We used Kids' Inpatient Database samples from 1997-2012 to identify discharges in non-Hispanic AI/AN and white children ages <5 years with a principal or secondary diagnosis code indicating LRTI. To address systematic underreporting and misclassification of race in administrative databases, population rates were estimated by deriving race- and year-specific denominators from hospital births.

RESULTS

During the study period, LRTI-associated discharge rates (per 1000) declined for white children (from 14.8 to 10.9; P < .001 for trend). For AI/AN children, rates varied widely by census region and were highest in the West, where they ranged from 38.6 in 1997 to 26.7 in 2012 (P = .35 for trend). Discharges in AI/AN children were associated with low household income, Medicaid insurance, and rural residence. In a case-cohort analysis of infants hospitalized with LRTI in 2012, discharge rates were higher for AI/AN infants than for white infants only in the West (72.8 vs 22.2; aOR, 2.5; 95% CI, 1.8-3.4).

CONCLUSIONS

Among young children who use nonfederal hospitals, LRTI-associated hospitalizations occur at substantially higher rates for AI/AN children than for white children. These hospitalizations occur at rates that are particularly high for AI/AN infants in the West, where rates are comparable with those reported for Indian Health Service enrollees.

Validity of Race, Ethnicity, and National Origin in Population-based Cancer Registries and Rapid Case Ascertainment Enhanced With a Spanish Surname List

BACKGROUND

Accurate information regarding race, ethnicity, and national origins is critical for identifying disparities in the cancer burden.

OBJECTIVES

To examine the use of a Spanish surname list to improve the quality of race-related information obtained from rapid case ascertainment (RCA) and to estimate the accuracy of race-related information obtained from cancer registry records collected by routine reporting.

SUBJECTS

Self-reported survey responses of 3954 participants from California enrolled in the Cancer Care Outcomes Research and Surveillance Consortium.

MEASURES

Sensitivity, specificity, positive predictive value, and percent agreement. We used logistic regression to identify predictors of underreporting and overreporting of a race/ethnicity.

RESULTS

Use of the Spanish surname list increased the sensitivity of RCA for Latino ethnicity from 37% to 83%. Sensitivity for cancer registry records collected by routine reporting was ≥95% for whites, blacks, and Asians, and specificity was high for all groups (86%-100%). However, patterns of misclassification by race/ethnicity were found that could lead to biased cancer statistics for specific race/ethnicities. Discordance between self-reported and registry-reported race/ethnicity was more likely for women, Latinos, and Asians.

CONCLUSIONS

Methods to improve race and ethnicity data, such as using Spanish surnames in RCA and instituting data collection guidelines for hospitals, are needed to ensure minorities are accurately represented in clinical and epidemiological research.

Annual Report to the Nation on the Status of Cancer, 1975-2012, featuring the increasing incidence of liver cancer

BACKGROUND

Annual updates on cancer occurrence and trends in the United States are provided through an ongoing collaboration among the American Cancer Society (ACS), the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR). This annual report highlights the increasing burden of liver and intrahepatic bile duct (liver) cancers.

METHODS

Cancer incidence data were obtained from the CDC, NCI, and NAACCR; data about cancer deaths were obtained from the CDC's National Center for Health Statistics (NCHS). Annual percent changes in incidence and death rates (age-adjusted to the 2000 US Standard Population) for all cancers combined and for the leading cancers among men and women were estimated by joinpoint analysis of long-term trends (incidence for 1992-2012 and mortality for 1975-2012) and short-term trends (2008-2012). In-depth analysis of liver cancer incidence included an age-period-cohort analysis and an incidence-based estimation of person-years of life lost because of the disease. By using NCHS multiple causes of death data, hepatitis C virus (HCV) and liver cancer-associated death rates were examined from 1999 through 2013.

RESULTS

Among men and women of all major racial and ethnic groups, death rates continued to decline for all cancers combined and for most cancer sites; the overall cancer death rate (for both sexes combined) decreased by 1.5% per year from 2003 to 2012. Overall, incidence rates decreased among men and remained stable among women from 2003 to 2012. Among both men and women, deaths from liver cancer increased at the highest rate of all cancer sites, and liver cancer incidence rates increased sharply, second only to thyroid cancer. Men had more than twice the incidence rate of liver cancer than women, and rates increased with age for both sexes. Among non-Hispanic (NH) white, NH black, and Hispanic men and women, liver cancer incidence rates were higher for persons born after the 1938 to 1947 birth cohort. In contrast, there was a minimal birth cohort effect for NH Asian and Pacific Islanders (APIs). NH black men and Hispanic men had the lowest median age at death (60 and 62 years, respectively) and the highest average person-years of life lost per death (21 and 20 years, respectively) from liver cancer. HCV and liver cancer-associated death rates were highest among decedents who were born during 1945 through 1965.

CONCLUSIONS

Overall, cancer incidence and mortality declined among men; and, although cancer incidence was stable among women, mortality declined. The burden of liver cancer is growing and is not equally distributed throughout the population. Efforts to vaccinate populations that are vulnerable to hepatitis B virus (HBV) infection and to identify and treat those living with HCV or HBV infection, metabolic conditions, alcoholic liver disease, or other causes of cirrhosis can be effective in reducing the incidence and mortality of liver cancer. Cancer 2016;122:1312-1337. © 2016 American Cancer Society.

Cancer incidence in indigenous people in Australia, New Zealand, Canada, and the USA: a comparative population-based study

INTRODUCTION

Indigenous people have disproportionally worse health and lower life expectancy than their non-indigenous counterparts in high-income countries. Cancer data for indigenous people are scarce and incidence has not previously been collectively reported in Australia, New Zealand, Canada, and the USA. We aimed to investigate and compare, for the first time, the cancer burden in indigenous populations in these countries.

METHODS

We derived incidence data from population-based cancer registries in three states of Australia (Queensland, Western Australia, and the Northern Territory), New Zealand, the province of Alberta in Canada, and the Contract Health Service Delivery Areas of the USA. Summary rates for First Nations and Inuit in Alberta, Canada, were provided directly by Alberta Health Services. We compared age-standardised rates by registry, sex, cancer site, and ethnicity for all incident cancer cases, excluding non-melanoma skin cancers, diagnosed between 2002 and 2006. Standardised rate ratios (SRRs) and 95% CIs were computed to compare the indigenous and non-indigenous populations of each jurisdiction, except for the Alaska Native population, which was compared with the white population from the USA.

FINDINGS

We included 24 815 cases of cancer in indigenous people and 5 685 264 in non-indigenous people from all jurisdictions, not including Alberta, Canada. The overall cancer burden in indigenous populations was substantially lower in the USA except in Alaska, similar or slightly lower in Australia and Canada, and higher in New Zealand compared with their non-indigenous counterparts. Among the most commonly occurring cancers in indigenous men were lung, prostate, and colorectal cancer. In most jurisdictions, breast cancer was the most common cancer in women followed by lung and colorectal cancer. The incidence of lung cancer was higher in indigenous men in all Australian regions, in Alberta, and in US Alaska Natives than in their non-indigenous counterparts. For breast cancer, rates in women were lower in all indigenous populations except in New Zealand (SRR 1·23, CI 95% 1·16-1·32) and Alaska (1·14, 1·01-1·30). Incidence of cervical cancer was higher in indigenous women than in non-indigenous women in most jurisdictions, although the difference was not always statistically significant.

INTERPRETATION

There are clear differences in the scale and profile of cancer in indigenous and non-indigenous populations in Australia, New Zealand, Canada, and the USA. Our findings highlight the need for much-improved, targeted programmes of screening, vaccination, and smoking cessation, among other prevention strategies. Governments and researchers need to work in partnership with indigenous communities to improve cancer surveillance in all jurisdictions and facilitate access to cancer data.

FUNDING

International Agency for Research on Cancer-Australia Fellowship.