Regional differences in colorectal cancer incidence, stage, and subsite among American Indians and Alaska Natives, 1999-2004

A comprehensive review of phytochemicals targeting macrophages for the regulation of colorectal cancer progression

BACKGROUND

Phytochemicals are natural compounds derived from plants, and are now at the forefront of anti-cancer research. Macrophage immunotherapy plays a crucial role in the treatment of colorectal cancer (CRC). In the context of colorectal cancer, which remains highly prevalent and difficult to treat, it is of research value to explore the potential mechanisms and efficacy of phytochemicals targeting macrophages for CRC treatment.

PURPOSE

The aim of this study was to gain insight into the role of phytochemical-macrophage interactions in regulating CRC and to provide a theoretical basis for the development of new therapeutic strategies in the future.

STUDY DESIGN

This review discusses the potential immune mechanisms of phytochemicals for the treatment of CRC by summarizing research of phytochemicals targeting macrophages.

METHODS

We reviewed the PubMed, EMBASE, Web of Science and CNKI databases from their initial establishment to July 2023 to classify and summaries phytochemicals according to their mechanism of action in targeting macrophages.

RESULTS

The results of the literature review suggest that phytochemicals interfere with CRC development by affecting macrophages through four main mechanisms. Firstly, they modulate the production of cytotoxic substances, such as NO and ROS, by macrophages to exert anticancer effects. Secondly, phytochemicals polarize macrophages towards the M1 phenotype, inhibit M2 polarisation and enhance the anti-tumour immune responses. Thirdly, they enhance the secretion of macrophage-derived cytokines and alter the tumour microenvironment, thereby inhibiting tumor growth. Finally, they activate the immune response by targeting macrophages, triggering the recruitment of other immune cells, thereby enhancing the immune killing effect and exerting anti-tumor effects. These findings highlight phytochemicals as potential therapeutic strategies to intervene in colorectal cancer development by modulating macrophage activity, providing a strong theoretical basis for future clinical applications.

CONCLUSION

Phytochemicals exhibit potential anti-tumour effects by modulating macrophage activity and intervening in the colorectal cancer microenvironment by multiple mechanisms.

Participatory action research to develop and implement multicomponent, multilevel strategies for implementing colorectal cancer screening interventions in American Indian communities in New Mexico

BACKGROUND

Despite the effectiveness of colorectal cancer (CRC) screening, American Indians (AIs) have low screening rates in the US. Many AIs receive care at Indian Health Services, Tribal, and Urban Indian (I/T/U) healthcare facilities, where published evidence regarding the implementation of CRC screening interventions is lacking. To address this gap, the University of New Mexico Comprehensive Cancer Center and the Albuquerque Area Southwest Tribal Epidemiology Center collaborated with two tribally-operated healthcare facilities in New Mexico with the goal of improving CRC screening rates among New Mexico's AI communities.

METHODS

Guided by the principles of Community Based Participatory Research, we engaged providers from the two tribal healthcare facilities and tribal community members through focus group (two focus groups with providers (n = 15) and four focus group and listening sessions with community members (n = 65)), to elicit perspectives on the feasibility and appropriateness of implementing The Guide to Community Preventive Services (The Community Guide) recommended evidence-based interventions (EBIs) and strategies for increasing CRC screening. Within each tribal healthcare facility, we engaged a Multisector Action Team (MAT) that participated in an implementation survey to document the extent to which their healthcare facilities were implementing EBIs and strategies, and an organizational readiness survey that queried whether their healthcare facilities could implement additional strategies to improve uptake of CRC screening.

RESULTS

The Community Guide recommended EBIs and strategies that received the most support as feasible and appropriate from community members included: one-on-one education from providers, reminders, small media, and interventions that reduced structural barriers. From the providers' perspective, feasible and acceptable strategies included one-on-one education, patient and provider reminders, and provider assessment and feedback. Universally, providers mentioned the need for patient navigators who could provide culturally appropriate education about CRC and assist with transportation, and improved support for coordinating clinical follow-up after screening. The readiness survey highlighted overall readiness of the tribal facility, while the implementation survey highlighted that few strategies were being implemented.

CONCLUSIONS

Findings from this study contribute to the limited literature around implementation research at tribal healthcare facilities and informed the selection of specific implementation strategies to promote the uptake of CRC screening in AI communities.

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.

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.

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.

Metabolic Syndrome and Colorectal Cancer Risk: Results of Propensity Score-Based Analyses in a Community-Based Cohort Study

Background: This study aimed to determine the effects of metabolic syndrome (MetS) on colorectal cancer (CRC) using propensity score (PS) methods. Methods: The study subjects were 2417 men and 4568 women from the Korean National Cancer Center (KNCC) Community Cohort enrolled between 2003 and 2010. Odds risks (ORs) and 95% confidence intervals (CIs) using PS matching analysis, regression models adjusted by the PS or stratified into five strata according to PS, and PS weighting methods were calculated. Results: In women, MetS and abnormally high triglyceride (TG) levels were associated with CRC risk using the PS matching analysis (ORs, for MetS, 2.19 (95% CI, 1.10–4.33); for abnormal TG levels, 2.08 (95% CI, 1.07–4.02)). However, there were no significant associations between MetS and TG levels and CRC risk in men. Conclusions: Our study might provide additional evidence that deteriorated metabolic profiles increase the risk of CRC in women rather than men. Thus, this may have an important role in effective population-level interventions for deteriorated metabolic profiles at an early stage.

Geographic and intra-racial disparities in early-onset colorectal cancer in the SEER 18 registries of the United States

Background

Although early‐onset colorectal cancer (EOCRC) incidence rates (IRs) are increasing, geographic and intra‐racial IR disparities are not well defined.

Methods

2000‐2015 Surveillance, Epidemiology, and End Results (SEER) program CRC IR Analysis (170,434 cases) was performed from ages 30 to 60 in four US regions, 18 individual registries, metropolitan and nonmetropolitan locations and stratified by race. Analyses were conducted in 1‐year and 5‐year age increments.

Results

Wide US regional EOCRC IR variations exist: For example, age 45 IRs in the south are 26.8/100,000, 36.0% higher than the West, 19.7/100,000 (p < 0.0001). Disparities magnify between individual registries: EOCRC IRs in highest risk registries were 177‐348% (Alaska Natives), 75‐200% (Hawaii), 76‐128% (Louisiana), and 61‐125% (Kentucky) higher than lowest risk registries depending on age. EOCRC IRs are 18.2%‐25.6% higher in nonmetropolitan versus metropolitan settings. Wide geographic intra‐racial disparities exist. Within the White population, the greatest IR difference (78.8%) was between Kentucky (5.9/100,000) and Los Angeles (3.3/100,000) in 30‐ to 34‐year‐olds (p < .0001). Within the Black population, the greatest difference (136.2%) was between rural Georgia (30.7/100,000) and California excluding San Francisco‐Oakland/San Jose‐Monterey/Los Angeles (13/100,000) in 40‐ to 44‐year‐olds (p = 0003).

Conclusion

Marked geographic EOCRC disparities exist with disproportionately high IRs in Alaska Natives, Hawaii, and southern registries. Geographic intra‐racial disparities are present within White and Black populations. In Blacks, there are disproportionately high EOCRC IRs in rural Georgia. Although vigilance is required in all populations, attention must be paid to these higher risk populations. Potential interventions include assuring early investigation of symptoms, targeting modifiable risk factors and utilizing earlier age 45 screening options supported by some guidelines.

High Prevalence of Adenomatous Polyps in Alaska Native People Aged 40-49 years

BACKGROUND

Although colorectal cancer occurs earlier in life and at twice the frequency in Alaska Native (AN) people compared with the general population, the colorectal polyp burden in this group has not been quantified. In addition, an appropriate age for initial screening in ANs has not been defined.

MATERIALS AND METHODS

A retrospective chart review of 766 AN people who had screening colonoscopy from 2015 to 2016 was performed. The polyp burden in patients aged 40-49 y was compared with that in those aged 50-59 y in both the AN and the general US populations.

RESULTS

In total, 345 adenomas were removed: 121 (35%) from 40- to 49-year-olds and 224 (65%) from 50- to 59-year-olds. Twenty-six percent of AN people aged 40 y to 49 y and 40% of AN people aged 50 to 59 y had at least one adenoma. Low- and high-risk adenomas were significantly less frequent in the younger group (22% versus 29%, P = 0.048; 9.2% versus 15%, P = 0.035; respectively). Advanced adenomas were also less frequent in the younger group, although not statistically significant. Polyp histology, size, location, and morphology did not differ significantly between groups.

CONCLUSIONS

The adenoma and advanced adenoma prevalence in 40- to 49-year-old AN people is high, suggesting colorectal cancer screening should begin at age 40 y in ANs.

Cancer survival among Alaska Native people

BACKGROUND

Recent cancer survival trends among American Indian and Alaska Native (AN) people are not well understood; survival has not been reported among AN people since 2001.

METHODS

This study examined cause-specific survival among AN cancer patients for lung, colorectal, female breast, prostate, and kidney cancers. It evaluated whether survival differed between cancers diagnosed in 1992-2002 (the earlier period) and cancers diagnosed in 2003-2013 (the later period) and by the age at diagnosis (<65 vs ≥65 years), stage at diagnosis (local or regional/distant/unknown), and sex. Kaplan-Meier and Cox proportional hazards models were used to estimate univariate and multivariate-adjusted cause-specific survival for each cancer.

RESULTS

An improvement was observed in 5-year survival over time from lung cancer (hazard ratio [HR] for the later period vs the earlier period, 0.83; 95% confidence interval [CI], 0.72-0.97), and a marginally nonsignificant improvement was observed for colorectal cancer (HR, 0.81; 95% CI, 0.66-1.01). Site-specific differences in survival were observed by age and stage at diagnosis.

CONCLUSIONS

This study presents the first data on cancer survival among AN people in almost 2 decades. During this time, AN people have experienced improvements in survival from lung and colorectal cancers. The reasons for these improvements may include increased access to care (including screening) as well as improvements in treatment. Improving cancer survival should be a priority for reducing the burden of cancer among AN people and eliminating cancer disparities. Cancer 2018;124:2570-7. © 2018 American Cancer Society.

Effect of Ulcerative Colitis on Incidence of Colorectal Cancer: Results from the Nationwide Population-Based Cohort Study (2003-2013)

PURPOSE

The colorectal cancer (CRC) is the third leading cause of death in Korea. Ulcerative colitis (UC) is regarded as a risk factor of CRC. The aim of study is to confirm the incidence of CRC among subjects with and without a diagnosis of UC based on a sample of the Korean population. This study identified the effect of UC on incidence of CRC in Korea.

METHOD

The data were from the population-based cohort containing National Health Insurance (NHI) claims from 2002 to 2013. We washed out first year (2002) for newly detected cases. Subjects who were under 20 years of age, diagnosed UC and CRC in 2002 development of CRC before diagnosis of UC since 2003, were excluded from analyses. Among 745,641 subjects during 11 years of follow-up (2003-2013), 7,448 patients with CRC were newly detected. Cox proportional hazard regression model was used to estimate the hazard ratio (HR) of UC for CRC incidence. Confounding variables including gender, baseline age, type of social security, income level, residence, Charlson Comorbidity Index, hypertension and diabetes mellitus were incorporated into the model.

RESULTS

Overall annual incidence of UC and CRC were 6.7 and 95.4 per 100,000 during 11 years (2003~2013), respectively. Among 522 of newly detected UC cases, CRC incident cases were 12 cases during 11 years. The effects were stronger for male. Advancing age and Charlson Comorbidity Index, hypertension and diabetes mellitus increased the risk of CRC. This study showed that the adjusted hazard ratio of UC in incidence of CRC is 1.92 (95% confidence interval: 1.09-3.38). Also, male patients with UC have more HR than female patients with UC.

CONCLUSION

The results of this study showed that patients with UC are the high risk group in incidence of CRC. Furthermore, the effects of UC in male patients are higher than those in female. The future study is needed to identify the effect of UC on mortality of CRC.

Genetics, Diet, and Season Are Associated with Serum 25-Hydroxycholecalciferol Concentration in a Yup'ik Study Population from Southwestern Alaska

BACKGROUND

Low blood vitamin D concentration is a concern for people living in circumpolar regions, where sunlight is insufficient for vitamin D synthesis in winter months and the consumption of traditional dietary sources of vitamin D is decreasing.

OBJECTIVE

The objective was to characterize the effects of diet, genetic variation, and season on serum 25-hydroxycholecalciferol [25(OH)D3] concentrations in Yup'ik Alaska Native people living in rural southwest Alaska.

METHODS

This study was a cross-sectional design that assessed the associations of traditional diet (via a biomarker, the RBC δ(15)N value), age, gender, body mass index (BMI), community location, and genotype of select single nucleotide polymorphisms (SNPs) in cytochrome P450 family 2, subfamily R, peptide 1 (CYP2R1), 7-dehydrocholesterol reductase (DHCR7), and vitamin D binding protein (GC) with serum 25(OH)D3 concentrations in 743 Yup'ik male and female participants, aged 14-93 y, recruited between September 2009 and December 2013.

RESULTS

Yup'ik participants, on average, had adequate concentrations of serum 25(OH)D3 (31.1 ± 1.0 ng/mL). Variations in diet, BMI, age, gender, season of sample collection, and inland or coastal community geography were all significantly associated with serum 25(OH)D3 concentration. In models not adjusting for other covariates, age, diet, and seasonal effects explained 33.7%, 20.7%, and 9.8%, respectively, of variability in serum 25(OH)D3 concentrations. Of the 8 SNPs interrogated in CYP2R1 and DHCR7, only rs11023374 in CYP2R1 was significantly associated with serum 25(OH)D3, explaining 1.5% of variability. The GC haplotype explained an additional 2.8% of variability. Together, age, diet, gender, season of sample collection, BMI, geography of the community, and genotype at rs11023374 explained 52.5% of the variability in serum 25(OH)D3 concentrations.

CONCLUSIONS

Lower consumption of the traditional diet was associated with lower serum concentrations of 25(OH)D3. Younger adults and youth in this community may be at increased risk of adverse outcomes associated with vitamin D insufficiency compared with older members of the community, especially during seasons of low sunlight exposure, because of lower consumption of dietary sources of vitamin D.

Targeting colorectal cancer stem cells using curcumin and curcumin analogues: insights into the mechanism of the therapeutic efficacy

Colorectal cancer is one of the commonest cancers in the world and it is also a common cause of cancer-related death worldwide. Despite advanced treatment strategies, the disease is rarely cured completely due to recurrence. Evidence shows that this is due to a small population of cells, called cancer stem cells (CSCs), in the tumour mass that have the self-renewal and differentiation potential to give rise to a new tumour population. Many pre-clinical and clinical studies have used curcumin and its analogues as anti-cancer agents in various types of cancer, including colorectal cancer. Intriguingly, curcumin and its analogues have also recently been shown to be effective in lowering tumour recurrence by targeting the CSC population, hence inhibiting tumour growth. In this review, we highlight the efficacy of curcumin and its analogues in targeting colorectal CSC and also the underlying molecular mechanism involved. Curcumin, in the presence or absence of other anti-cancer agents, has been shown to reduce the size of tumour mass and growth in both in vivo and in vitro studies by affecting many intracellular events that are associated with cancer progression and CSC formation. An insight into the molecular mechanism has unraveled the mode of action via which curcumin could affect the key regulators in CSC, importantly; (1) the signaling pathways, including Wnt/β-catenin, Sonic Hedgehog, Notch and PI3K/Akt/mTOR, (2) microRNA and (3) the epithelial-mesenchymal transition at multiple levels. Therefore, curcumin could play a role as chemosensitiser whereby the colorectal CSCs are now sensitised towards the anti-cancer therapy, therefore, combination therapy using anti-cancer agent with curcumin could be much more effective than treatment using a single cancer agent. This potential treatment modality can be further developed by employing an effective delivery system using a nanotechnology based approach to treat colorectal cancer.

Socioecological perspectives on cervical cancer and cervical cancer screening among Asian American women

Although cervical cancer is one of the most commonly diagnosed cancers among Vietnamese American women (VAW) and Korean American women (KAW), both groups consistently report much lower rates of cervical cancer screening compared with other Asian ethnic subgroups and non-Hispanic Whites. This study aimed to explore multilevel factors that may underlie low screening rates among VAW and KAW living in a city where their ethnic communities are relatively small. The socioecological model was used as a conceptual framework. Thirty participants were conveniently recruited from ethnic beauty salons run by VA and KA cosmetologists in Albuquerque, New Mexico. The participants' average age was 44.6 years (SD = .50; range = 21-60). Most participants were married (80 %) and employed (73.3 %), and had health insurance (83.3 %). A qualitative interview was conducted in Vietnamese or Korean and transcribed verbatim. A thematic content analysis was used to identify major codes, categories, and patterns across the transcripts. The study identified several factors at the individual (e.g., pregnancy, poverty, personality), interpersonal (e.g., family responsibility, mother as influential referent), and community (e.g., lack of availability, community size) levels. The study sheds light on four major areas that must be taken into consideration in the development of culturally appropriate, community-based interventions aimed to reduce disparities in cervical cancer screening among ethnic minority women in the United States: (1) ethnic community size and geographic location; (2) cross-cultural similarities and dissimilarities; (3) targeting of not only unmarried young women, but also close referents; and (4) utilization of trusted resources within social networks.

Cancer disparities among Alaska native people, 1970-2011

INTRODUCTION

Cancer is the leading cause of death among Alaska Native people. The objective of this study was to examine cancer incidence data for 2007-2011, age-specific rates for a 15-year period, incidence trends for 1970-2011, and mortality trends for 1990-2011.

METHODS

US data were from the Surveillance, Epidemiology, and End Results (SEER) Program SEER*Stat database and from the SEER Alaska Native Tumor Registry. Age-adjusted cancer incidence rates among Alaska Native people and US whites were compared using rate ratios. Trend analyses were performed using the Joinpoint Regression Program. Mortality data were from National Center for Health Statistics.

RESULTS

During 2007-2011 the cancer incidence rate among Alaska Native women was 16% higher than the rate among US white women and was similar among Alaska Native men and US white men. Incidence rates among Alaska Native people exceeded rates among US whites for nasopharyngeal, stomach, colorectal, lung, and kidney cancer. A downward trend in colorectal cancer incidence among Alaska Native people occurred from 1999 to 2011. Significant declines in rates were not observed for other frequently diagnosed cancers or for all sites combined. Cancer mortality rates among Alaska Native people during 2 periods, 1990-2000 and 2001-2011, did not decline. Cancer mortality rates among Alaska Native people exceeded rates among US whites for all cancers combined; for cancers of the lung, stomach, pancreas, kidney, and cervix; and for colorectal cancer.

CONCLUSION

Increases in colorectal screening among Alaska Native people may be responsible for current declines in colorectal cancer incidence; however; improvements in treatment of colon and rectal cancers may also be contributing factors.

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.

The impact of rural health care accessibility on cancer-related behaviors and outcomes

BACKGROUND

This research seeks to identify the relationship between economic factors related to the ability to receive and pay for health services and adverse cancer outcomes, as well as preventative screening and behavioral factors that influence the risk of cancer. We focus on the Northern High Plains region, where we are able to compare regions with extremely low access to health services with those with relatively high levels of access.

OBJECTIVE

This study aims to identify health disparities in rural communities, particularly among Native American populations, and, thereby, begin to determine the most effective means by which to deliver health services to areas where geography, economics, and culture might prevent traditional models of health delivery from providing sufficient incentives for the prevention of adverse cancer-related outcomes.

METHODS

The Health Care Accessibility Index (HCAI) is computed through the use of principal component analysis and includes economic variables as well as variables concerning institutional and geographic access to health care. Index values are then regressed onto cancer outcomes, cancer-prevention outcomes, and cancer-related risk, using weighted least squares and quantile regressions.

RESULTS

Counties with relatively poor access to health care (low HCAI) also have statistically (1) lower breast cancer screening rates, (2) higher smoking prevalence, (3) higher obesity prevalence, and (4) higher cancer-related mortality rates. Breast cancer screening is found to be especially sensitive to areas of low health accessibility.

CONCLUSIONS

Empirical results provide support for policy efforts to increase the accessibility of health care services that are targeted to areas with low mammography screening rates, high obesity rates, high smoking prevalence, as well as areas near Native American reservation territories.

A comparison of colorectal cancer screening uptake among average-risk insured American Indian/Alaska Native and white women

INTRODUCTION

American Indian and Alaska Native (AI/AN) women have among the lowest rates of colorectal cancer (CRC) screening. Whether screening disparities persist with equal access to health care is unknown.

METHODS

Using administrative data from 1996-2007, we compared CRC screening events for 286 AI/AN and 14,042 White women aged 50 years and older from a health maintenance organization in the Pacific Northwest of the U.S.

RESULTS

The proportion of AI/AN and White women screened for CRC at age 50 was similar (13.3% vs. 14.0%, p =.74). No differences were seen in the type of screening test. Time elapsed to first screening among AI/AN women who were not screened at age 50 did not differ from White women (hazard ratio 1.0, 95% confidence interval 0.8-1.3).

CONCLUSIONS

Uptake for CRC screening was similar among insured AI/AN and White women, suggesting that when access to care is equal, racial disparities in screening diminish.

Geographic variations in access and utilization of cancer screening services: examining disparities among American Indian and Alaska Native Elders

Background

Despite recommendations for cancer screening for breast and colorectal cancer among the Medicare population, preventive screenings rates are often lower among vulnerable populations such as the small but rapidly growing older American Indian and Alaska Native (AIAN) population. This study seeks to identify potential disparities in the availability of screening services, distance to care, and the utilization of cancer screening services for Medicare beneficiaries residing in areas with a higher concentration of AIAN populations.

Methods

Using the county (n =3,225) as the level of analysis, we conducted a cross-sectional analysis of RTI International’s Spatial Impact Factor Data (2012) to determine the level of disparities for AIAN individuals. The outcomes of interest include: the presence of health care facilities in the county, the average distance in miles to the closest provider of mammography and colonoscopy (analyzed separately) and utilization of screening services (percent of adults aged 65 and older screened by county).

Results

Counties with higher concentrations of AIAN individuals had greater disparities in access and utilization of cancer screening services. Even after adjusting for income, education, state of residence, population 65 and older and rurality, areas with higher levels of AIAN individuals were more likely to see disparities with regard to health care services related to mammograms (p ≤ .05; longer distance, lower screening) and colonoscopies (p ≤ .05; longer distance, lower screening).

Conclusions

These findings provide evidence of a gap in service availability, utilization and access facing areas with higher levels of AIAN individuals throughout the US. Without adequate resources in place, these areas will continue to have less access to services and poorer health which will be accelerated as the population of older adults grows.

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.

The influence of health disparities on targeting cancer prevention efforts

Despite the advances in cancer medicine and the resultant 20% decline in cancer death rates for Americans since 1991, there remain distinct cancer health disparities among African Americans, Hispanics, Native Americans, and the those living in poverty. Minorities and the poor continue to bear the disproportionate burden of cancer, especially in terms of stage at diagnosis, incidence, and mortality. Cancer health disparities are persistent reminders that state-of-the-art cancer prevention, diagnosis, and treatment are not equally effective for and accessible to all Americans. The cancer prevention model must take into account the phenotype of accelerated aging associated with health disparities as well as the important interplay of biological and sociocultural factors that lead to disparate health outcomes. The building blocks of this prevention model will include interdisciplinary prevention modalities that encourage partnerships across medical and nonmedical entities, community-based participatory research, development of ethnically and racially diverse research cohorts, and full actualization of the prevention benefits outlined in the 2010 Patient Protection and Affordable Care Act. However, the most essential facet should be a thoughtful integration of cancer prevention and screening into prevention, screening, and disease management activities for hypertension and diabetes mellitus because these chronic medical illnesses have a substantial prevalence in populations at risk for cancer disparities and cause considerable comorbidity and likely complicate effective treatment and contribute to disproportionate cancer death rates.

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.

Views, barriers, and suggestions for colorectal cancer screening among american Indian women older than 50 years in the midwest

OBJECTIVE

Although colorectal cancer (CRC) mortality rates in the US population have shown a decline, American Indian (AI) CRC mortality rates appear to be increasing. CRC screening rates of AIs remain low when compared with other ethnic groups. The research team explored women's perceptions toward CRC screening, existing barriers, and suggestions to promote education and screening among AI women in Kansas and Missouri.

METHODS

Using a community-based participatory research approach, the authors conducted 7 focus groups with AI women older than 50 years (N = 52) to better understand their perceptions of and attitudes toward CRC screening.

RESULTS

Women recognized barriers to screening, such as embarrassment, privacy issues, fear, insurance, and cost. They countered perceived barriers through inventive suggestions for education and awareness via social support systems and intergenerational relationships.

DISCUSSION

CRC screening interventions for AI must be culturally tailored.

Native cancer navigation: the state of the science

The purpose of this literature review is to determine the current state of the science for the effectiveness of patient navigation on improving outcomes of cancer care across the continuum among Native Americans. The research will help healthcare professionals ascertain potential evidence-based practice guidelines and gaps in knowledge, which may provide direction for future research. Data synthesis included the use of Native navigation for cancer care, which has been demonstrated in limited, nonrandomized studies to improve cancer knowledge, access to care, and quality of life for Native Americans. Those studies had limitations, including small sample size, self-report of outcome measures, and lack of randomization. Evidence is insufficient to conclude that the use of Native navigation is superior to usual cancer care for Native American patients. Oncology nurses have a role in training personnel to serve as cancer navigators. Nurses need to be supportive of culturally appropriate navigation programs and know about services provided by navigators. In addition, nurse educators need to encourage Native Americans in their communities to consider choosing nursing as a profession. If an oncology nurse has an interest in research, opportunities exist to assist with or conduct research projects regarding Native cancer navigation. A particular need exists for addressing the gaps in research identified in this article.

The Alaska Education and Research Towards Health (EARTH) Study: cancer risk factors

The Alaska Education and Research Towards Health (EARTH) Study assessed cancer risk among 3,821 Alaska Native people (AN). We present the prevalence of selected cancer risk factors and comparison with Healthy People 2010 goals. Participants completed extensive computer-assisted self-administered questionnaires on diet, physical activity, tobacco and alcohol use, cancer screening, family history of cancer, and environmental exposures. Measurement data were collected on blood pressure, height, weight, waist/hip circumference, fasting serum lipids, and glucose. Cancer risk factors are high for the Alaska EARTH study population. For all risk factors studied except for vegetable consumption, Alaska EARTH Study participants did not meet Healthy People 2010 goals. This study is unique in providing questionnaire and measurement data of cancer risk factors on a larger study sample than any previous study among AN living in Alaska. Data show that the prevalence of most cancer risk factors exceeded national recommendations. Given the disease disparities that exist for the AN population, these data provide important baseline data that can be used to target health interventions and reduce health disparities.

American Indian/Alaska Native cancer policy: systemic approaches to reducing cancer disparities

Members of American Indian and Alaska Native (AI/AN) tribes have a unique political status in the United States in terms of citizenship, and that political status determines eligibility for certain unique healthcare services. The AI/AN population has a legal right to healthcare services based on treaties, court decisions, acts of Congress, Executive Orders, and other legal bases. Although the AI/AN population has a right to healthcare services, the Indian Health Service (the federal agency responsible for providing healthcare to AI/ANs) is severely underfunded, limiting access to services (including cancer care). In order to overcome distinct cancer health disparities, policy changes will be needed. This paper reviews the historical pattern of AI/AN healthcare and the challenges of the complex care needed from prevention through end-of-life care for cancer.

Effect of tribal language use on colorectal cancer screening among American Indians

American Indians have one of the lowest colorectal cancer (CRC) screening rates for any racial/ethnic group in the U.S., yet reasons for their low screening participation are poorly understood. We examine whether tribal language use is associated with knowledge and use of CRC screening in a community-based sample of American Indians. Using logistic regression to estimate the association between tribal language use and CRC test knowledge and receipt we found participants speaking primarily English were no more aware of CRC screening tests than those speaking primarily a tribal language (OR = 1.16 [0.29, 4.63]). Participants who spoke only a tribal language at home (OR = 1.09 [0.30, 4.00]) and those who spoke both a tribal language and English (OR = 1.74 [0.62, 4.88]) also showed comparable odds of receipt of CRC screening. Study findings failed to support the concept that use of a tribal language is a barrier to CRC screening among American Indians.

The last frontier: innovative efforts to reduce colorectal cancer disparities among the remote Alaska Native population

BACKGROUND

The Alaska Native (AN) population experiences twice the incidence and mortality of colorectal cancer (CRC) as does the U.S. white population. CRC screening allows early detection and prevention of cancer.

OBJECTIVE

We describe pilot projects conducted from 2005 to 2010 to increase CRC screening rates among AN populations living in rural and remote Alaska.

DESIGN

Projects included training rural mid-level providers in flexible sigmoidoscopy, provision of itinerant endoscopy services at rural tribal health facilities, the creation and use of a CRC first-degree relative database to identify and screen individuals at increased risk, and support and implementation of screening navigator services.

SETTING

Alaska Tribal Health System.

PATIENTS

AN population.

INTERVENTIONS

Itinerant endoscopy, patient navigation.

MAIN OUTCOME MEASUREMENTS

AN patients screened for CRC, colonoscopy quality measures.

RESULTS

As a result of these ongoing efforts, statewide AN CRC screening rates increased from 29% in 2000 to 41% in 2005 before the initiation of these projects and increased to 55% in 2010. The provision of itinerant CRC screening clinics increased rural screening rates, as did outreach to average-risk and increased-risk (family history) ANs by patient navigators. However, health care system barriers were identified as major obstacles to screening completion, even in the presence of dedicated patient navigators.

LIMITATIONS

Continuing challenges include geography, limited health system capacity, high staff turnover, and difficulty getting patients to screening appointments.

CONCLUSIONS

The projects described here aimed to increase CRC screening rates in an innovative and sustainable fashion. The issues and solutions described may provide insight for others working to increase screening rates among geographically dispersed and diverse populations.

Regional differences in dialysis care and mortality among American Indians and Alaska Natives

American Indians/Alaska Natives (AIANs) compose a heterogeneous population that includes geographically distinct tribal communities, many with high rates of ESRD. Regional features of dialysis care and mortality are unknown in this population. Here, we describe the structure of dialysis care and mortality of adult AIANs who initiated maintenance dialysis during 1995-2008 in different regions of the US. Overall, 13,716 AIANs received dialysis at 2054 facilities. Approximately 10% (n = 197) of these facilities provided care to two-thirds (n = 9011) of AIANs. AIANs from the Southwest and Alaska were concentrated in relatively few dialysis facilities whereas those in the Eastern US and Pacific Coast were distributed more diffusely. Despite comparably high rates of poverty, diabetes, and cardiovascular disease, annual mortality rates were lower in the Southwest (13.9%) compared with the Southern Plains (23.2%), Alaska (21.2%), Eastern US (20.0%), Northern Plains (20.8%), and Pacific Coast (22.0%). These regional differences were consistent over time and persisted after adjusting for sociodemographic and clinical variables and area-based poverty. In conclusion, regional differences in the structure of dialysis care and patient mortality exist among AIANs. Southwestern AIANs experience the highest concentration of dialysis care and the lowest mortality. Our findings suggest that an area-based approach examining the care structure of relatively few dialysis facilities may delineate determinants of these differences and improve the quality of care to many AIAN communities.

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

BACKGROUND

Studies on colorectal cancer (CRC) screening and incidence among American Indian/Alaska Natives (AI/AN) are few.

AIMS

Our aim was to determine CRC screening prevalence and to calculate CRC incidence among AI/AN receiving care within the Indian Health Service (IHS).

METHODS

A retrospective cohort study of AI/AN who utilized IHS from 1996 to 2004. AI/AN who were average-risk for CRC and received primary care within IHS were identified by searching the IHS Resource Patient Management System for selected ICD-9/CPT codes (n = 142,051). CRC screening prevalence was calculated and predictors of screening were determined for this group. CRC incidence rates were ascertained for the entire AI/AN population ages 50-80 who received IHS medical care between 1996 and 2004 (n = 283,717).

RESULTS

CRC screening was performed in 4.0% of average-risk AI/AN. CRC screening was more common among women than men (RR = 1.6, 95% CI 1.4-1.7) and among AI/AN living in the Alaska region compared to the Pacific Coast region (RR = 2.5, 95% CI 2.2-2.8) while patients living in the Northern Plains (RR = 0.4, 95% CI 0.3-0.4) were less likely to have been screened. CRC screening was less common among patients with a greater number of primary care visits. The age-adjusted CRC incidence among AI/AN ages 50-80 was 227 cancers per 100,000 person-years.

CONCLUSIONS

CRC was common among AI/AN receiving medical care within IHS. However, CRC screening prevalence was far lower than has been reported for the U.S. population.

Cancer-related disparities and opportunities for intervention in Northern Plains American Indian communities

OBJECTIVES

We examined behavioral trends associated with cancer risk and cancer screening use from 1997 through 2006 among American Indians/Alaska Natives (AI/ANs) in the Northern Plains region (North Dakota, South Dakota, Nebraska, and Iowa) of the United States. We also examined disparities between that population and non-Hispanic white (NHW) people in the Northern Plains and AI/ANs in other regions.

METHODS

We analyzed Behavioral Risk Factor Surveillance System data from the Centers for Disease Control and Prevention for 1997-2000 and 2003-2006. We used age-adjusted Wald Chi-square tests to test the difference between these two periods for AI/ANs and the difference between AI/ANs and NHW people during 2003-2006.

RESULTS

There was no statistically significant improvement among AI/ANs in the Northern Plains region for behaviors associated with cancer risk or cancer screening use, and there was a significant increase in the obesity rate. The prevalence of binge drinking, obesity, and smoking among AI/ANs in the Northern Plains was significantly higher than among NHW people in the same region and among AI/AN populations in other regions. Although the percentage of cancer screening use was similar for all three groups, the use of sigmoidoscopy/colonoscopy was significantly lower among the Northern Plains AI/ANs than among NHW people.

CONCLUSION

These results indicate a need for increased efforts to close the gaps in cancer health disparities between AI/ANs and the general population. Future efforts should focus not only on individual-level changes, but also on system-level changes to build infrastructure to promote healthy living and to increase access to cancer screening.

Is distance to provider a barrier to care for medicaid patients with breast, colorectal, or lung cancer?

PURPOSE

Distance to provider might be an important barrier to timely diagnosis and treatment for cancer patients who qualify for Medicaid coverage. Whether driving time or driving distance is a better indicator of travel burden is also of interest.

METHODS

Driving distances and times from patient residence to primary care provider were calculated for 3,917 breast, colorectal (CRC) and lung cancer Medicaid patients in Washington State from 1997 to 2003 using MapQuest.com. We fitted regression models of stage at diagnosis and time-to-treatment (number of days between diagnosis and surgery) to test the hypothesis that travel burden is associated with timely diagnosis and treatment of cancer.

FINDINGS

Later stage at diagnosis for breast cancer Medicaid patients is associated with travel burden (OR = 1.488 per 100 driving miles, P= .037 and OR = 1.270 per driving hour, P= .016). Time-to-treatment after diagnosis of CRC is also associated with travel burden (14.57 days per 100 driving miles, P= .002 and 5.86 days per driving hour, P= .018).

CONCLUSIONS

Although travel burden is associated with timely diagnosis and treatment for some types of cancer, we did not find evidence that driving time was, in general, better at predicting timeliness of cancer diagnosis and treatment than driving distance. More intensive efforts at early detection of breast cancer and early treatment of CRC for Medicaid patients who live in remote areas may be needed.

Australia's national bowel cancer screening program: does it work for indigenous Australians?

BACKGROUND

Despite a lower incidence of bowel cancer overall, Indigenous Australians are more likely to be diagnosed at an advanced stage when prognosis is poor. Bowel cancer screening is an effective means of reducing incidence and mortality from bowel cancer through early identification and prompt treatment. In 2006, Australia began rolling out a population-based National Bowel Cancer Screening Program (NBCSP) using the Faecal Occult Blood Test. Initial evaluation of the program revealed substantial disparities in bowel cancer screening uptake with Indigenous Australians significantly less likely to participate in screening than the non-Indigenous population.This paper critically reviews characteristics of the program which may contribute to the discrepancy in screening uptake, and includes an analysis of organisational, structural, and socio-cultural barriers that play a part in the poorer participation of Indigenous and other disadvantaged and minority groups.

METHODS

A search was undertaken of peer-reviewed journal articles, government reports, and other grey literature using electronic databases and citation snowballing. Articles were critically evaluated for relevance to themes that addressed the research questions.

RESULTS

The NBCSP is not reaching many Indigenous Australians in the target group, with factors contributing to sub-optimal participation including how participants are selected, the way the screening kit is distributed, the nature of the test and comprehensiveness of its contents, cultural perceptions of cancer and prevailing low levels of knowledge and awareness of bowel cancer and the importance of screening.

CONCLUSIONS

Our findings suggest that the population-based approach to implementing bowel cancer screening to the Australian population unintentionally excludes vulnerable minorities, particularly Indigenous and other culturally and linguistically diverse groups. This potentially contributes to exacerbating the already widening disparities in cancer outcomes that exist among Indigenous Australians. Modifications to the program are recommended to facilitate access and participation by Indigenous and other minority populations. Further research is also needed to understand the needs and social and cultural sensitivities of these groups around cancer screening and inform alternative approaches to bowel cancer screening.

Sex disparities in colorectal cancer incidence by anatomic subsite, race and age

Although incidence of colorectal cancer (CRC) in the United States has declined in recent years, rates remain higher in men than in women and the male-to-female incidence rate ratio (MF IRR) increases progressively across the colon from the cecum to the rectum. Rates among races/ethnicities other than Whites or Blacks have not been frequently reported. To examine CRC rates by sex across anatomic subsite, age and racial/ethnic groups, we used the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program for cases diagnosed among residents of 13 registries during 1992-2006. Incidence rates were expressed per 100,000 person-years and age-adjusted to the 2000 US Standard Population; MF IRR and 95% confidence intervals were also calculated. Among each racial/ethnic group, the MF IRR increased fairly monotonically from close to unity for cecal cancers to 1.81 (Hispanics) for rectal cancers. MF IRRs increased with age most rapidly for distal colon cancers from <1.0 at ages <50 years to 1.4-1.9 at older ages. The MF IRR for rectal cancers also rose with age from about 1.0 to 2.0. For proximal cancer, the MF IRR was consistently <1.5; among American Indian/Alaska Natives, it was <1.0 across all ages. The MF IRRs for CRC vary markedly according to subsite and age but less by racial/ethnic group. These findings may partially reflect differences in screening experiences and access to medical care but also suggest that etiologic factors may be playing a role.

Prostate cancer incidence among American Indian and Alaska Native men, US, 1999-2004

BACKGROUND

American Indian and Alaska Native (AI/AN) men experience lower incidence of prostate cancer than other race/ethnic populations in the US, but racial misclassification of AI/AN men threatens the validity of these estimates. To the authors' knowledge, little is known concerning prostate-specific antigen (PSA) testing in AI/AN men.

METHODS

The authors linked cancer registry data with Indian Health Service enrollment records to improve race classification. Analyses comparing cancer incidence rates and stage at diagnosis for AI/AN and non-Hispanic white (NHW) men for 6 geographic regions focused on counties known to have less race misclassification. The authors also used Behavioral Risk Factors Surveillance System data to characterize PSA testing in AI/AN men.

RESULTS

Prostate cancer incidence rates were generally lower in AI/AN than in NHW men for all regions combined (rate ratio of 0.68). However, regional variation was noted among AI/AN men, with incidence rates (per 100,000 population) ranging from 65.7 in the Southwest to 174.5 on the Northern Plains. The rate of distant stage disease was somewhat higher among AI/AN (7.8) than NHW (6.2) men. Nationally, AI/AN men were less likely than NHW men to have undergone recent PSA testing (48.4% vs 58.0%), with prominent regional variation in screening rates noted.

CONCLUSIONS

Prostate cancer incidence rates and the proportion of men with recent PSA testing were lower for AI/AN men than for NHW men. However, incident rates and rate of distant stage varied by region more for AI/AN than for NHW. Further research is needed among AI/AN men to evaluate strategies for better understanding the causes of the regional variation in prostate cancer incidence.

Cancer in American Indian and Alaska Native young adults (ages 20-44 years): US, 1999-2004

BACKGROUND

An examination of cancer incidence patterns in American Indians and Alaska Native (AI/AN) young adults may provide insight into their present and future cancer burden.

METHODS

To reduce racial misclassification, incidence data were linked with the Indian Health Service (IHS) patient services database. Age-adjusted cancer incidence rates per 100,000 (AAR) and corresponding rate ratios (RR) for young adults (ages 20-44 years) were compared across IHS regions and for selected cancers within Contract Health Service Delivery Area counties by race (AI/AN vs non-Hispanic whites [NHW]) and sex.

RESULTS

The all-sites cancer incidence rate was lower for AI/ANs (AAR of 83.8) than for NHWs (AAR of 111.2) (RR of 0.75) but varied by IHS regions. Among the leading cancers in AI/AN females the risk was elevated for stomach (RR of 3.22), colorectal (RR of 1.30), uterine (RR of 1.61), and kidney (RR of 1.39) cancers and was lower for breast (RR of 0.70) and thyroid (RR of 0.71) cancers. Among AI/AN young adult males the risk was elevated for stomach (RR of 2.62), liver (RR of 1.89), and kidney (RR of 1.59) cancers and lower for testicular germ cell cancer (RR of 0.64) and lymphoma (RR of 0.60). The risk for these and other cancers varied across IHS regions.

CONCLUSIONS

Many of the cancer patterns that characterize the AI/AN population overall are apparent among young adults. Compared with NHW young adults, the overall cancer burden among AI/AN young adults was lower but varied for selected cancers and across IHS regions. Cancer control and research strategies are needed to address the unique genetic, social, cultural, and lifestyle aspects of AI/AN young adults.

Introduction to the supplement on cancer in the American Indian and Alaska Native populations in the United States

The collection of papers in this Supplement combines cancer incidence data from the National Program of Cancer Registries and the Surveillance, Epidemiology, and End Results program, enhanced by record linkages and geographic factors, to provide a comprehensive description of the cancer burden in the American Indian/Alaska Native population in the United States. Cancer incidence rates among this population varied widely, sometimes more than 5-fold, by geographic region.