Screening prevalence and incidence of colorectal cancer among American Indian/Alaskan natives in the Indian Health Service

Evaluating Disparities in Colon Cancer Survival in American Indian/Alaskan Native Patients Using the National Cancer Database

BACKGROUND

Studies demonstrate higher mortality rates from colon cancer in American Indian/Alaskan Native (AI/AN) patients compared to non-Hispanic White (nHW). We aim to identify factors that contribute to survival disparities.

METHODS

We used the National Cancer Database to identify AI/AN (n = 2127) and nHW (n = 527,045) patients with stage I-IV colon cancer from 2004 to 2016. Overall survival among stage I-IV colon cancer patients was estimated by Kaplan-Meier analysis; Cox proportional hazard ratios were used to identify independent predictors of survival.

RESULTS

AI/AN patients with stage I-III disease had significantly shorter median survival than nHW (73 vs 77 months, respectively; p < 0.001); there were no differences in survival for stage IV. Adjusted analyses demonstrated that AI/AN race was an independent predictor of higher overall mortality compared to nHW (HR 1.19, 95% CI 1.01-1.33, p = 0.002). Importantly, compared to nHW, AI/AN were younger, had more comorbidities, had greater rurality, had more left-sided colon cancers, had higher stage but lower grade tumors, were less frequently treated at an academic facility, were more likely to experience a delay in initiation of chemotherapy, and were less likely to receive adjuvant chemotherapy for stage III disease. We found no differences in sex, receipt of surgery, or adequacy of lymph node dissection.

CONCLUSION

We found patient, tumor, and treatment factors that potentially contribute to worse survival rates observed in AI/AN colon cancer patients. Limitations include the heterogeneity of AI/AN patients and the use of overall survival as an endpoint. Additional studies are needed to implement strategies to eliminate disparities.

Colorectal cancer screening participation in First Nations populations worldwide: a systematic review and data synthesis

Background

First Nations populations have poorer colorectal cancer (CRC) survival compared to non-First Nations populations. Whilst First Nations populations across the world are distinct, shared experiences of discrimination and oppression contribute to persistent health inequities. CRC screening improves survival, however screening rates in First Nations populations are poorly described. This study seeks to define participation rates in CRC screening in First Nations populations worldwide.

Methods

A systematic literature search was conducted of PubMed, Embase, Cochrane Library, CINAHL, MEDLINE, grey literature, national registries and ClinicalTrials.gov. All sources were searched from their inception date to 18 February 2024. Studies were included if they reported CRC screening rates in adult (≥18 years) First Nations populations. We aimed to undertake a meta-analysis if there were sufficient data. Quality of papers were assessed using the Joanna Briggs Institute (JBI) appraisal tool. The study was registered with PROSPERO, CRD42020210181.

Findings

The literature search identified 1723 potentially eligible published studies. After review, 57 studies were included, 50 from the United States (US), with the remaining studies from Australia, Aotearoa New Zealand (NZ), Canada, Dominica and Guatemala. Additionally, eleven non-indexed reports from national programs in Australia and NZ were included. There were insufficient data to undertake meta-analysis, therefore a systematic review and narrative synthesis were conducted. CRC screening definitions varied, and included stool-based screening, sigmoidoscopy and colonoscopy. US First Nations screening rates ranged between 4.0 and 79.2%, Australia reported 10.6-35.2%, NZ 18.4-49%, Canada 22.4-53.4%, Guatemala 2.2% and Dominica 4.2%. Fifty-five studies were assessed as moderate or high quality and two as low quality.

Interpretation

Our findings suggested that there is wide variation in CRC screening participation rates across First Nations populations. Screening data are lacking in direct comparator groups and longitudinal outcomes. Disaggregation of screening data are required to better understand and address First Nations CRC outcome inequities.

Funding

None.

Access to Lung Cancer Screening Among American Indian and Alaska Native Adults: A Qualitative Study

BACKGROUND

Lung cancer is the leading cause of cancer mortality among American Indian and Alaska Native populations. American Indian and Alaska Native people use commercial tobacco products at higher rates compared with all other races and ethnicities. Moreover, they show lower adherence to cancer screening guidelines.

RESEARCH QUESTION

How do American Indian and Alaska Native adults perceive and use lung cancer screening?

STUDY DESIGN AND METHODS

We conducted a study in which we recorded and transcribed data from three focus groups consisting of American Indian and Alaska Native adults. Participants were recruited through convenience sampling at a national health conference. Transcripts were analyzed by inductive coding.

RESULTS

Participants (n = 58) of 28 tribes included tribal Elders, tribal leaders, and non-Native volunteers who worked with tribal communities. Limited community awareness of lung cancer screening, barriers to lung cancer screening at health care facilities, and health information-seeking behaviors emerged as key themes in discussions. Screening knowledge was limited except among people with direct experiences of lung cancer. Cancer risk factors such as multigenerational smoking were considered important priorities to address in communities. Limited educational and diagnostic resources are significant barriers to lung cancer screening uptake in addition to limited discussions with health care providers about cancer risk.

INTERPRETATION

Limited access to and awareness of lung cancer screening must be addressed. American Indian and Alaska Native adults use several health information sources unique to tribal communities, and these should be leveraged in designing screening programs. Equitable partnerships between clinicians and tribes are essential in improving knowledge and use of lung cancer screening.

Identifying Priorities and Strategies for Improving Colorectal Cancer Screening in Tribal Clinics

BACKGROUND

Colorectal cancer (CRC) is the 3^rd most frequently diagnosed cancer and the 2^nd leading cause of cancer death in the United States (US), and incidence and mortality rates in Oklahoma are higher for many American Indian (AI) populations than other populations. The AI CRC Screening Consortium addresses major regional CRC screening disparities among AIs with shared objectives to increase CRC screening delivery and uptake in AIs aged 50 to 75 years at average risk for CRC and to assess the effectiveness of implementations of the interventions. This manuscript reports environmental scan findings related to current practices and multi-stakeholder experiences with CRC screening in two Oklahoma Indian health care systems.

METHOD

We conducted a mixed methods environmental scan across five clinical sites and with multiple stakeholders to determine the scope and scale of colorectal cancer screening in two separate AI health care delivery systems in Oklahoma. Data collection consisted of a mixture of individual interviews and group discussions at an urban site, and four clinical care sites within a tribal health system.

RESULTS

Sixty-two individuals completed interviews. Data from these interviews will inform the development of evidence-based intervention strategies to increase provider delivery, community access to, and community priority for CRC screening in diverse AI health care delivery systems. Conversations with patients, providers, and clinical leadership point to individual and system-level opportunities for improvement at each site, shaped in part by differences in the delivery of services, structure of the health care system, and capacity to implement new intervention strategies. The thematic areas most central to the process of evidenced-based intervention development included: current practices, needs and recommendations, and CRC site priorities.

CONCLUSION

Environmental scan data indicated clear opportunities for individual and system-level interventions to enhance CRC screening and was critical for understanding readiness for EBI implementation at each site.

American Indian/Alaska native access to colorectal cancer screening: Does gastroenterologist density matter?

BACKGROUND

American Indians/Alaska Natives (AI/AN) receive less colorectal cancer (CRC) screening than other populations. Using gastroenterologist (GI) locations as a measure of colonoscopy access, we correlate GI density and AI/AN CRC screening rates.

METHODS

We identified GIs from the 2016 National Provider Identifier registry, and calculated GI density per 100,000 people. We identified screening, demographic, and socioeconomic variables from the 2016 Behavioral Risk Factor Surveillance System Survey. GI density and CRC screening rates were analyzed with Multivariable Poisson regression.

RESULTS

In states with GI Density greater than 3.98/100,000, odds of AI/AN CRC screening are 1.27-1.37 times higher than in states below this threshold (p < 0.036).

CONCLUSIONS

GI density has a limited association on CRC screening, with decrease impact beyond threshold of 3.98 GI/100,000. Minimal access to GIs is important in improving AI/AN CRC screening; however, further research is required to elucidate the most critical factors contributing to CRC screening.

Colorectal cancer community engagement: a qualitative exploration of American Indian voices from North Dakota

Background

American Indians (AI) in North Dakota present with higher rates of advanced-stage disease for screening detectable colorectal cancers and have lower overall baseline colorectal cancer screening rates than non-AIs. We sought to identify the perceived barriers and facilitators for the engagement with colorectal cancer prevention within North Dakota tribal communities.

Methods

Twelve semi-structured interviews were carried out across four tribal reservation communities in the state of North Dakota with American Indian adults between the ages of 30 and 75 years. We utilized purposive sampling to ensure maximum variation in age, sex, and tribal community until data saturation was achieved. The interviews were transcribed, and thematic analysis was carried out to identify consistent themes rooted within the data. Ethical approval was gained for this project from all relevant institutional review boards.

Results

Four main themes were identified as barriers for the engagement with colorectal cancer prevention, including: colorectal cancer screening barriers, focused on other health problems, lack of colorectal cancer tailored health promotion, and socio-cultural factors affecting colorectal cancer prevention. Three main themes were identified as facilitators for the engagement with colorectal cancer prevention, including: reasons for getting colorectal cancer screening, role of culture, and getting out into the community.

Conclusion

There is need for more community-rooted, strengths-based approaches to colorectal cancer prevention activities in AI communities in North Dakota. Socio-cultural factors, such as the use of storytelling, and the use of traditional knowledge have been demonstrated to be an important element of consideration for colorectal cancer tribal community engagement and prevention planning in the state.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09119-2.

Colorectal Cancer: In the Pursuit of Health Equity

Colorectal cancer mortality has decreased considerably following the adoption of national screening programs, yet, within at-risk subgroups, there continue to be measurable differences in clinical outcomes from variations in screening, receipt of chemotherapy, radiation or surgery, access to clinical trials, research participation, and survivorship. These disparities are well-described and some have worsened over time. Disparities identified have included race and ethnicity, age (specifically young adults), socioeconomic status, insurance access, geography, and environmental exposures. In the context of the COVID-19 pandemic, colorectal cancer care has necessarily shifted dramatically, with broad, immediate uptake of telemedicine, transition to oral medications when feasible, and considerations for sequence of treatment. However, it has additionally marginalized patients with colorectal cancer with historically disparate cancer-specific outcomes; among them, uninsured, low-income, immigrant, and ethnic-minority patients-all of whom are more likely to become infected, be hospitalized, and die of either COVID-19 or colorectal cancer. Herein, we outline measurable disparities, review implemented solutions, and define strategies toward ensuring that all have a fair and just opportunity to be as healthy as possible.

Colorectal cancer statistics, 2020

Colorectal cancer (CRC) is the second most common cause of cancer death in the United States. Every 3 years, the American Cancer Society provides an update of CRC occurrence based on incidence data (available through 2016) from population-based cancer registries and mortality data (through 2017) from the National Center for Health Statistics. In 2020, approximately 147,950 individuals will be diagnosed with CRC and 53,200 will die from the disease, including 17,930 cases and 3,640 deaths in individuals aged younger than 50 years. The incidence rate during 2012 through 2016 ranged from 30 (per 100,000 persons) in Asian/Pacific Islanders to 45.7 in blacks and 89 in Alaska Natives. Rapid declines in incidence among screening-aged individuals during the 2000s continued during 2011 through 2016 in those aged 65 years and older (by 3.3% annually) but reversed in those aged 50 to 64 years, among whom rates increased by 1% annually. Among individuals aged younger than 50 years, the incidence rate increased by approximately 2% annually for tumors in the proximal and distal colon, as well as the rectum, driven by trends in non-Hispanic whites. CRC death rates during 2008 through 2017 declined by 3% annually in individuals aged 65 years and older and by 0.6% annually in individuals aged 50 to 64 years while increasing by 1.3% annually in those aged younger than 50 years. Mortality declines among individuals aged 50 years and older were steepest among blacks, who also had the only decreasing trend among those aged younger than 50 years, and excluded American Indians/Alaska Natives, among whom rates remained stable. Progress against CRC can be accelerated by increasing access to guideline-recommended screening and high-quality treatment, particularly among Alaska Natives, and elucidating causes for rising incidence in young and middle-aged adults.

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.

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.

Health disparities in colorectal cancer among racial and ethnic minorities in the United States

In the 2010 Census, just over one-third of the United States (US) population identified themselves as being something other than being non-Hispanic white alone. This group has increased in size from 86.9 million in 2000 to 111.9 million in 2010, representing an increase of 29 percent over the ten year period. Per the American Cancer Society, racial and ethnic minorities are more likely to develop cancer and die from it when compared to the general population of the United States. This is particularly true for colorectal cancer (CRC). The primary aim of this review is to highlight the disparities in CRC among racial and ethnic minorities in the United States. Despite overall rates of CRC decreasing nationally and within certain racial and ethnic minorities in the US, there continue to be disparities in incidence and mortality when compared to non-Hispanic whites. The disparities in CRC incidence and mortality are related to certain areas of deficiency such as knowledge of family history, access to care obstacles, impact of migration on CRC and paucity of clinical data. These areas of deficiency limit understanding of CRC's impact in these groups and when developing interventions to close the disparity gap. Even with the implementation of the Patient Protection and Affordable Healthcare Act, disparities in CRC screening will continue to exist until specific interventions are implemented in the context of each of racial and ethnic group. Racial and ethnic minorities cannot be viewed as one monolithic group, rather as different segments since there are variations in incidence and mortality based on natural history of CRC development impacted by gender, ethnicity group, nationality, access, as well as migration and socioeconomic status. Progress has been made overall, but there is much work to be done.

Variations in Colorectal Cancer Screening of Medicare Beneficiaries Served by Rural Health Clinics

This study aims (1) to examine the trends and patterns of colorectal cancer screening (CCS) of Medicare beneficiaries in rural areas by state and year (before and after Affordable Care Act [ACA] enactment) and (2) to investigate the contextual, organizational, and aggregated patient characteristics influencing variations in care received by patients of rural health clinics (RHCs). The following 2 hypotheses were formulated: (1) CCS rates are higher in the post-ACA period than in the pre-ACA period, irrespective of the factors rurality, poverty, dually eligible status, and the organizational characteristics of RHCs and (2) the contextual and organizational factors of RHCs exert more influence on the variation in CCS rates of RHC patients than do aggregated personal factors. We used administrative data on CCS rates (2007 through 2012) for rural Medicare beneficiaries. Autoregressive growth curve modeling of the CCS rates was performed. A generalized estimating equation of selected predictors was analyzed. Of the 9 predictors, 5 were statistically significant: The ACA and the percentage of female patients had a positive effect on the CCS rate, whereas regional location, years of RHC certification, and average age of patients had a negative effect on the CCS rate. The predictors accounted for 40.2% of the total variance in CCS. Results show that in rural areas of 9 states, the enactment of ACA improved CCS rates, contextual, organizational, and patient characteristics being considered. Improvement in preventive care will be expected, as the ACA is implemented in the United States.

Knowledge, attitudes, and behaviours towards cancer screening in indigenous populations: a systematic review

Cancer mortality among indigenous peoples is increasing, but these populations commonly under use cancer-screening services. This systematic review explores knowledge, attitudes, and behaviours towards cancer screening among indigenous peoples worldwide. Searches of major bibliographic databases identified primary studies published in English up to March, 2014; of 33 eligible studies, three were cohort studies, 27 cross-sectional, and three case-control. Knowledge of and participation in screening was greater for breast cancer than for other cancers. Indigenous peoples tended to have less knowledge, less favourable attitudes, and a higher propensity to refuse screening than non-indigenous populations. The most common factors affecting knowledge, attitudes, and behaviours towards cancer screening included access to screening, knowledge about cancer and screening, educational attainment, perceived necessity of screening, and age. Greater understanding of knowledge, attitudes, and behaviours towards cancer screening in diverse indigenous cultures is needed so that culturally appropriate cancer prevention programmes can be provided.

United States colorectal cancer screening practices among American Indians/Alaska Natives, blacks, and non-Hispanic whites in the new millennium (2001 to 2010)

BACKGROUND

The objectives of this study were to describe, examine, and compare prevalence estimates of colorectal cancer (CRC) screening practices and to determine whether disparities exist for American Indians/Alaska Natives (AIANs) and blacks compared with whites.

METHODS

Behavioral Risk Factor Surveillance System (2001-2010) data from respondents aged ≥ 50 years (n = 356,073) were used. The primary outcome was self-reported CRC screening according to US Preventive Services Task Force guidelines for endoscopy (colonoscopy or sigmoidoscopy), fecal occult blood test (FOBT), or mixed screening (endoscopy or FOBT).

RESULTS

From 2001 to 2010, endoscopy screening increased in the AIAN population by 44.8% (P < .001) compared with black respondents (51.7%) and white respondents (26.5%). AIANs were less likely to report endoscopy screening (45%) compared with both blacks (56%) and whites (55%). For mixed CRC screenings, AIAN rates increased by 34.5%, compared with 29.7% for blacks and 15% for whites. In 2010, AIANs (51%) had the lowest prevalence of mixed CRC screening compared with blacks (61%) and whites (60%; P < .001). Factors that enabled health care attenuated the lowered likelihood of CRC screenings, but disparities remained for AIAN CRC screening. In contrast, once enabling factors were controlled, the odds ratios of CRC screening among blacks were higher compared with whites.

CONCLUSIONS

Between 2001 and 2010, AIANs had the lowest CRC screening rates in the United States compared with blacks and whites, presenting a CRC disparity, as rigorously defined. The current findings indicate that, although considerable progress has been made to increase CRC screening for blacks and whites, progress for AIANs continues to lag behind in the first decade of 21st century.

Geographic variation in colorectal cancer incidence and mortality, age of onset, and stage at diagnosis among American Indian and Alaska Native people, 1990-2009

OBJECTIVES

We characterized estimates of colorectal cancer (CRC) in American Indians/Alaska Natives (AI/ANs) compared with Whites using a linkage methodology to improve AI/AN classification in incidence and mortality data.

METHODS

We linked incidence and mortality data to Indian Health Service enrollment records. Our analyses were restricted to Contract Health Services Delivery Area counties. We analyzed death and incidence rates of CRC for AI/AN persons and Whites by 6 regions from 1999 to 2009. Trends were described using linear modeling.

RESULTS

The AI/AN colorectal cancer incidence was 21% higher and mortality 39% higher than in Whites. Although incidence and mortality significantly declined among Whites, AI/AN incidence did not change significantly, and mortality declined only in the Northern Plains. AI/AN persons had a higher incidence of CRC than Whites in all ages and were more often diagnosed with late stage CRC than Whites.

CONCLUSIONS

Compared with Whites, AI/AN individuals in many regions had a higher burden of CRC and stable or increasing CRC mortality. An understanding of the factors driving these regional disparities could offer critical insights for prevention and control programs.

Challenges and possible solutions to colorectal cancer screening for the underserved

Colorectal cancer (CRC) is a leading cause of cancer mortality worldwide. CRC incidence and mortality can be reduced through screening. However, in the United States, screening participation remains suboptimal, particularly among underserved populations such as the uninsured, recent immigrants, and racial/ethnic minority groups. Increasing screening rates among underserved populations will reduce the US burden of CRC. In this commentary focusing on underserved populations, we highlight the public health impact of CRC screening, list key challenges to screening the underserved, and review promising approaches to boost screening rates. We identify four key policy and research priorities to increase screening among underserved populations: 1) actively promote the message, "the best test is the one that gets done"; 2) develop and implement methods to identify unscreened individuals within underserved population groups for screening interventions; 3) develop and implement approaches for organized screening delivery; and 4) fund and enhance programs and policies that provide access to screening, diagnostic follow-up, and CRC treatment for underserved populations. This commentary represents the consensus of a diverse group of experts in cancer control and prevention, epidemiology, gastroenterology, and primary care from across the country who formed the Coalition to Boost Screening among the Underserved in the United States. The group was organized and held its first annual working group meeting in conjunction with the World Endoscopy Organization's annual Colorectal Cancer Screening Committee meeting during Digestive Disease Week 2012 in San Diego, California.

Barriers to colorectal cancer screening among American Indian men aged 50 or older, Kansas and Missouri, 2006-2008

American Indian (AI) men have some of the highest rates of colorectal cancer (CRC) in the United States but among the lowest screening rates. Our goal was to better understand awareness and discourse about colorectal cancer in a heterogeneous group of AI men in the Midwestern United States. Focus groups were conducted with AI men (N = 29); data were analyzed using a community-participatory approach to qualitative text analysis. Several themes were identified regarding knowledge, knowledge sources, and barriers to and facilitators of screening. Men in the study felt that awareness about colorectal cancer was low, and people were interested in learning more. Education strategies need to be culturally relevant and specific.

American Indian perceptions of colorectal cancer screening: viewpoints from adults under age 50

Colorectal cancer (CRC) mortality rates have decreased in the general US population; however, CRC mortality rates are increasing among American Indians (AI). AI CRC screening rates remain low when compared to other ethnic groups. Our team investigated CRC screening education prior to recommended age for screening to better understand screening perceptions among AI community members. Our research team conducted 11 focus groups with AI men and women aged 30-49 (N = 39 men and N = 31 women) in Kansas and Missouri. The results revealed that community members (1) have little knowledge of CRC, (2) do not openly discuss CRC, and (3) want additional CRC education. Variations existed among men and women's groups, but they agreed that preventive measures need to be appropriate for AI communities. Thus, AI CRC screening interventions should be culturally tailored to better meet the needs of the population.

Colorectal cancer in alaska native people, 2005-2009

BACKGROUND

Colorectal cancer (CRC) is the most frequently diagnosed cancer among Alaska Native (AN) people, and the second leading cause of cancer death. The incidence rate for the combined years 1999 through 2003 was 30% higher than the rate among U.S. whites (USWs) for the same period. Current incidence rates may serve to monitor the impact of screening programs in reducing CRC in the AN population.

METHODS

Incidence data are from the Alaska Native Tumor Registry and the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) Program. We compared AN CRC incidence, survival rates, and stage at diagnosis with rates in USWs for cases diagnosed from 2005 through 2009. Relative survival calculations were produced in SEER*Stat by the actuarial method.

RESULTS

The CRC age-adjusted incidence rate among AN men and women combined was higher than those in USW men and women (84 vs. 43/100,000; P < .05; AN:USW rate ratio [RR] = 2.0). The greatest differences between rates in AN people and USWs were for tumors in the hepatic flexure (RR = 3.1) and in the transverse (RR = 2.9) and sigmoid (RR = 2.5) regions of the colon. Rectal cancer rates among AN people were significantly higher than rates in USWs (21 vs.12/100,000). Five-year relative survival proportions by stage at diagnosis indicate that the CRC 5-year relative survival was similar in AN people and USWs for the period 2004 through 2009.

CONCLUSIONS

The high rate of CRC in AN people emphasizes the need for screening programs and interventions to reduce known modifiable risks. Research in methods to promote healthy behaviors among AN people is greatly needed.