Computer-Aided Detection Improves Adenomas per Colonoscopy for Screening and Surveillance Colonoscopy: A Randomized Trial.

BACKGROUND & AIMS: Colonoscopy for colorectal cancer screening is endoscopist dependent, and colonoscopy quality improvement programs aim to improve efficacy. This study evaluated the clinical benefit and safety of using a computer-aided detection (CADe) device in colonoscopy procedures. METHODS: This randomized study prospectively evaluated the use of a CADe device at 5 academic and community centers by US board-certified gastroenterologists (n = 22). Participants aged ≥40 scheduled for screening or surveillance (≥3 years) colonoscopy were included; exclusion criteria included incomplete procedure, diagnostic indication, inflammatory bowel disease, and familial adenomatous polyposis. Patients were randomized by endoscopist to the standard or CADe colonoscopy arm using computer-generated, random-block method. The 2 primary endpoints were adenomas per colonoscopy (APC), the total number of adenomas resected divided by the total number of colonoscopies; and true histology rate (THR), the proportion of resections with clinically significant histology divided by the total number of polyp resections. The primary analysis used a modified intention-to-treat approach. RESULTS: Between January and September 2021, 1440 participants were enrolled to be randomized. After exclusion of participants who did not meet the eligibility criteria, 677 in the standard arm and 682 in the CADe arm were included in a modified intention-to-treat analysis. APC increased significantly with use of the CADe device (standard vs CADe: 0.83 vs 1.05, P = .002; total number of adenomas, 562 vs 719). There was no decrease in THR with use of the CADe device (standard vs CADe: 71.7% vs 67.4%, P for noninferiority < .001; total number of non-neoplastic lesions, 284 vs 375). Adenoma detection rate was 43.9% and 47.8% in the standard and CADe arms, respectively (P = .065). CONCLUSIONS: For experienced endoscopists performing screening and surveillance colonoscopies in the United States, the CADe device statistically improved overall adenoma detection (APC) without a concomitant increase in resection of non-neoplastic lesions (THR). CLINICALTRIALS: gov registration: NCT04754347.

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

Objective: To determine if masculinity barriers to medical care and the death from colorectal cancer (CRC) of actor Chadwick Boseman (The Black Panther) influenced CRC early-detection screening intent among unscreened American Indian/Alaska Native (AIAN) and Non-Hispanic-Black (Black) men compared with Non-Hispanic-White (White) men. Methods: Using a consumer-panel, we surveyed U.S. men aged 18-75 years (N = 895) using the 24-item Masculinity Barriers to Medical Care (MBMC) scale. We calculated the median score to create binary exposures to evaluate associations with CRC screening intent and conducted multivariable logistic regression to evaluate independent associations stratified by race/ethnicity. Results: Overall, Black respondents were most likely to have a high MBMC score (55%) compared to White (44%) and AIAN (51%) men (p = 0.043). AIAN men were least likely to report CRC screening intent (51.1%) compared with Black (68%) and White men (64%) (p < 0.001). Black men who reported the recent death of Chadwick Boseman increased their awareness of CRC were more likely (78%) to report intention to screen for CRC compared to those who did not (56%) (p < 0.001). Black men who exhibited more masculinity-related barriers to care were more likely to intend to screen for CRC (OR: 1.76, 95% CI: 0.98-3.16) than their counterparts, as were Black men who reported no impact of Boseman's death on their CRC awareness (aOR: 2.96, 95% CI: 1.13-7.67). Conversely, among AIAN men, those who exhibited more masculinity-related barriers to care were less likely to have CRC screening intent (aOR: 0.47, 95% CI: 0.27-0.82) compared with their counterparts. Conclusions: Masculinity barriers to medical care play a significant role in intention to screen for CRC. While Black men were most likely to state that The Black Panther's death increased their awareness of CRC, it did not appear to modify the role of masculine barriers in CRC screening intention as expected. Further research is warranted to better understand how masculine barriers combined with celebrity-driven health-promotion interventions influence the uptake of early-detection screening for CRC. Impact: Our study provides formative data to develop behavioral interventions focused on improving CRC screening completion among diverse men.

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

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

Triage of General Gastrointestinal Endoscopic Procedures During the COVID-19 Pandemic: Results From a National Delphi Consensus Panel.

BACKGROUND AND AIMS: As the COVID-19 pandemic moves into the postpeak period, the focus has now shifted to resuming endoscopy services to meet the needs of patients who were deferred. By using a modified Delphi process, we sought to develop a structured framework to provide guidance regarding procedure indications and procedure time intervals. METHODS: A national panel of 14 expert gastroenterologists from throughout the US used a modified Delphi process, to achieve consensus regarding: (1) common indications for general endoscopy, (2) critical patient-important outcomes for endoscopy, (3) defining time-sensitive intervals, (4) assigning time-sensitive intervals to procedure indications. Two anonymous rounds of voting were allowed before attempts at consensus were abandoned. RESULTS: Expert panel reached consensus that procedures should be allocated to one of three timing categories: (1) time-sensitive emergent = scheduled within 1 week, (2) time-sensitive urgent = scheduled within 1-8 weeks, (3) nontime sensitive = defer to > 8 weeks and reassess timing then. The panel identified 62 common general endoscopy indications (33 for EGD, 21 for colonoscopy, 5 for sigmoidoscopy). Consensus was reached on patient-important outcomes for each procedure indication, and consensus regarding timing of the procedure indication was achieved for 74% of indications. Panelists also identified adequate personal-protective-equipment, rapid point-of-care testing, and staff training as critical preconditions before endoscopy services could be resumed. CONCLUSION: We used the validated Delphi methodology, while prioritized patient-important outcomes, to provide consensus recommendations regarding triaging a comprehensive list of general endoscopic procedures.

Adenomas per colonoscopy and adenoma per positive participant as quality indicators for screening colonoscopy.

Background and study aims Adenomas per colonoscopy (APC) and adenomas per positive patient (APP) have been proposed as additional quality indicators but their association with adenoma detection rate (ADR) is not well studied. The aim of our study was to evaluate the variability in APC and APP, their association with ADR, and associated risk factors in screening colonoscopies from a community practice. Patients and methods We calculated the APC, APP, and ADR from all screening colonoscopies performed over 5 years. We used adjusted hierarchical logistic regression to assess the association of factors with APC, APP, and ADR. Results There were 80,915 screening colonoscopies by 60 gastroenterologists. The median (Q1-Q3) APC, APP, and ADR were 0.41 (0.36 - 0.53), 1.33 (1.23 - 1.40), and 0.32 (0.28 - 0.38), respectively. Despite the high correlation between APC and ADR, 47.6 % of endoscopists with the lowest APC had a higher ADR, and no endoscopists with the highest APC had a lower ADR. Of endoscopists with the lowest APP, 74.3 % had a higher ADR and 5.6 % of endoscopists with the highest APP had a lower ADR. Factors associated with higher APC after multivariable adjustment included: older patients age (OR 1.003; 95 % CI 1.002 - 1.005), male patients (OR 1.123; 95 % CI 1.090 - 1.156), younger endoscopist age (OR 0.943; 95 % CI 0.941 - 0.945), and longer withdrawal time (OR 3.434; 95 % CI 2.941 - 4.010). Factors associated with higher APP were male sex, younger endoscopist age, and longer withdrawal time. Conclusion APC and APP provides additional information about endoscopist performance. Younger endoscopist age and longer withdrawal time are associated with colonoscopy quality.

Influences and Practices in Colorectal Cancer Screening Among Health Care Providers Serving Northern Plains American Indians, 2011-2012.

INTRODUCTION: The epidemiology of colorectal cancer, including incidence, mortality, age of onset, stage of diagnosis, and screening, varies regionally among American Indians. The objective of the Improving Northern Plains American Indian Colorectal Cancer Screening study was to improve understanding of colorectal cancer screening among health care providers serving Northern Plains American Indians. METHODS: Data were collected, in person, from a sample of 145 health care providers at 27 health clinics across the Northern Plains from May 2011 through September 2012. Participants completed a 32-question, self-administered assessment designed to assess provider practices, screening perceptions, and knowledge. RESULTS: The proportion of providers who ordered or performed at least 1 colorectal cancer screening test for an asymptomatic, average-risk patient in the previous month was 95.9% (139 of 145). Of these 139 providers, 97.1% ordered colonoscopies, 12.9% ordered flexible sigmoidoscopies, 73.4% ordered 3-card, guaiac-based, fecal occult blood tests, and 21.6% ordered fecal immunochemical tests. Nearly two-thirds (64.7%) reported performing in-office guaiac-based fecal occult blood tests using digital rectal examination specimens. Providers who reported receiving a formal update on colorectal cancer screening during the previous 24 months were more likely to screen using digital rectal exam specimens than providers who had received a formal update on colorectal cancer screening more than 24 months prior (73.9% vs 56.9%, respectively, χ2 = 4.29, P = .04). CONCLUSION: Despite recommendations cautioning against the use of digital rectal examination specimens for colorectal cancer screening, the practice is common among providers serving Northern Plains American Indian populations. Accurate up-to-date, ongoing education for patients, the community, and health care providers is needed.

COLORECTAL CANCER SCREENING PRACTICES AMONG THREE AMERICAN INDIAN COMMUNITIES IN MINNESOTA.

Colorectal cancer (CRC) is a leading cause of cancer morbidity and mortality. Effective prevention and early detection may be achieved through screening, but screening rates are low, especially in American Indian (AI) populations. We wanted to understand perceptions of CRC screening among AI located in the Great Lakes region. Focus groups were recorded and transcribed verbatim (N = 45). Data were analyzed using qualitative text analysis. Themes that deterred CRC screening were low CRC knowledge, fear of the procedure and results, cost and transportation issues, and a lack of quality and competent care. Suggestions for improvement included outreach efforts and culturally-tailored teaching materials.

Sorting it Out: Pile Sorting as a Mixed Methodology for Exploring Barriers to Cancer Screening.

We discuss a mixed methodology for analyzing pile sorting data. We created a list of 14 barriers to colon cancer screening and recruited 18, 13, and 14 participants from three American Indian (AI) communities to perform pile sorting. Quantitative data were analyzed by cluster analysis and multidimensional scaling. Differences across sites were compared using permutation bootstrapping. Qualitative data collected during sorting were compiled by AI staff members who determined names for the clusters found in quantitative analysis. Results showed 5 clusters of barriers in each site although barriers in the clusters varied slightly across sites. Simulation demonstrated type I error rates around the nominal 0.05 level whereas power depended on the numbers of clusters, and between and within cluster variability.

Mortality caused by chronic liver disease among American Indians and Alaska Natives in the United States, 1999-2009.

OBJECTIVES: We compared chronic liver disease (CLD) mortality from 1999 to 2009 between American Indians and Alaska Natives (AI/ANs) and Whites in the United States after improving CLD case ascertainment and AI/AN race classification. METHODS: We defined CLD deaths and causes by comprehensive death certificate-based diagnostic codes. To improve race classification, we linked US mortality data to Indian Health Service enrollment records, and we restricted analyses to Contract Health Service Delivery Areas and to non-Hispanic populations. We calculated CLD death rates (per 100,000) in 6 geographic regions. We then described trends using linear modeling. RESULTS: CLD mortality increased from 1999 to 2009 in AI/AN persons and Whites. Overall, the CLD death rate ratio (RR) of AI/AN individuals to Whites was 3.7 and varied by region. The RR was higher in women (4.7), those aged 25 to 44 years (7.4), persons residing in the Northern Plains (6.4), and persons dying of cirrhosis (4.0) versus hepatocellular carcinoma (2.5), particularly those aged 25 to 44 years (7.7). CONCLUSIONS: AI/AN persons had greater CLD mortality, particularly from premature cirrhosis, than Whites, with variable mortality by region. Comprehensive prevention and care strategies are urgently needed to stem the CLD epidemic among AI/AN individuals.

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.

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.

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.

Culture and colorectal cancer screening on three American Indian reservations.

BACKGROUND: Colorectal cancer (CRC) rates among many American Indian populations are high. Screening by fecal occult blood test (FOBT) and endoscopy is effective for reducing CRC mortality, but little research has examined the extent of such screening in reservation populations. Further, nothing is known of how American Indians' cultural characteristics may be related to screening receipt. PARTICIPANTS AND SETTING: We examined data from participants recruited from 2 Northern Plains and 1 Southwest reservation for the Education and Research Toward Health (EARTH) study. All participants aged > or = 51 years were eligible for inclusion. DESIGN: After calculating screening rates, we examined bivariate relationships between screening and participant characteristics, including measures of cultural characteristics including ethnic identity and use of traditional healing practices. We applied multivariate regression to relate these cultural variables to odds of lifetime screening by FOBT or endoscopy. RESULTS: Of 751 American Indians sampled, 35% reported lifetime CRC screening by at least one modality. Multivariate analyses did not reveal significant relationships or trends relating FOBT to respondents' cultural characteristics. By contrast, odds of endoscopy were significantly lower among persons who spoke a tribal language at home (OR .6, 95% C.I. .4-.9), and trend analysis revealed an inverse relationship between endoscopy and number of identity measures endorsed (Ptrend<.1). CONCLUSIONS: The sampled population exhibits disparities in CRC compared to the general population, and cultural characteristics are related to odds of endoscopy. Findings warrant culturally tailored CRC screening initiatives for American Indians.

A survey of Indian Health Service and tribal health providers' colorectal cancer screening knowledge, perceptions, and practices.

BACKGROUND: Provider recommendation is critical for colorectal cancer (CRC) screening participation, yet few data exist on practices of providers serving American Indians and Alaska Natives. We examined Indian Health Service (IHS) and tribal provider practices, beliefs about screening efficacy, and perceptions of barriers. METHODS: We developed a Web-based questionnaire and recruited respondents via electronic distribution lists. We generated descriptive statistics by region, provider type, and workplace setting. RESULTS: Most respondents (77%) recommend starting CRC screening of average-risk patients at age 50; however, 22% recommend flexible sigmoidoscopy and 43% colonoscopy at intervals inconsistent with national guidelines. Of those recommending fecal occult blood test (FOBT), 23% use a single, in-office FOBT card as their only FOBT method. Respondents reported barriers to screening to include underutilized reminder systems and inadequate resources. CONCLUSIONS: Indian Health Service/tribal providers are knowledgeable about when to begin CRC screening; however, education about the appropriate use and frequency of CRC tests is needed.

Plastic versus self-expanding metallic stents for malignant hilar biliary obstruction: a prospective multicenter observational cohort study.

BACKGROUND: There are few comparative data as to whether plastic or self-expanding metallic stents are preferable for palliating malignant hilar biliary obstruction. METHODS: Thirty-day outcomes of consecutive endoscopic retrograde cholangiopancreatographies performed for malignant hilar obstruction at 6 private and 5 university centers were assessed prospectively. RESULTS: Patients receiving plastic (N=28) and metallic stents (N=34) were similar except that metallic stent recipients more often had: Bismuth III or IV tumors (16/34 vs. 5/28 P=0.043), higher Charlson comorbidity scores (P=0.003), metastatic disease (P=0.006), and management at academic centers (P=0.018). The groups had similar rates of bilateral stent placement (4/28 vs. 5/34), and similar frequency of opacified but undrained segmental ducts (7/28 vs. 5/34). Adverse outcomes including cholangitis, stent occlusion, migration, perforation, and/or the need for unplanned endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography occurred in 11/28 (39.3%) patients with plastic versus 4/34 (11.8%) with metal stents (P=0.017). By logistic regression, factors associated with adverse outcomes included plastic stent placement (odds ratio 6.32; 95% confidence interval 1.23, 32.56) and serum bilirubin (1.11/mg/dL above normal: 1.01, 1.22) but not center type or Bismuth class. CONCLUSIONS: Metallic stent performance was superior to plastic for hilar tumor palliation with respect to short-term outcomes, independent of disease severity, Bismuth class, or drainage quality.

Gastric cancer among American Indians and Alaska Natives in the United States, 1999-2004.

BACKGROUND: Gastric cancer incidence rates for American Indians and Alaska Natives (AI/ANs) historically have exceeded those for non-Hispanic whites (NHWs). Previous reports may have underestimated the true burden of gastric cancer in AI/AN populations because of misclassification of AI/AN race in cancer registries. METHODS: Population-based cancer registry data from 1999 through 2004 were used to describe gastric cancer incidence in AI/ANs and NHWs in the US. To address misclassification of race, registry data were linked with Indian Health Service administrative records, and analyses were restricted to residents of Contract Health Service Delivery Areas (CHSDA). Disease patterns were assessed for 6 geographic regions and for all regions combined. Rates were expressed per 100,000 population and were age-adjusted to the 2000 US standard population. RESULTS: In CHSDA counties, gastric cancer incidence rates for AI/ANs were higher than the rates for NHWs across most regions. For both sexes combined, AI/AN rates ranged from 6.1 in the East region to 24.5 in Alaska; there was relatively little regional variation in NHW rates. Most patients with gastric cancer were diagnosed with late-stage disease, regardless of race, age, or sex. In some regions, cancer rates in the central/distal portions of the stomach were higher among AI/ANs than among NHWs, whereas rates in the proximal stomach were similar between the 2 populations. CONCLUSIONS: AI/ANs are generally at greater risk for gastric cancer than NHWs. Relatively high rates of cancer in the central/distal portions of the stomach among AI/ANs in some geographic regions may indicate a disproportional burden of Helicobacter pylori-associated disease.

Primary liver cancer incidence among American Indians and Alaska Natives, US, 1999-2004.

BACKGROUND: American Indians and Alaska Natives (AI/AN) experience higher morbidity and mortality from primary liver cancer than other United States (US) populations, but racial misclassification in medical records results in underestimates of disease burden. METHODS: To reduce misclassification, National Program of Cancer Registries and Surveillance, Epidemiology, and End Results data were linked with Indian Health Service (IHS) enrollment records to compare primary liver cancer incidence and stage at diagnosis between AI/AN and non-Hispanic whites (NHW) living within the regionalized IHS Contract Health Service Delivery Area counties. Incidence rates are expressed per 100,000 persons and age-adjusted by 19 age groups to the 2000 US standard population. RESULTS: Overall, AI/AN have a higher proportion of hepatocellular carcinoma compared with NHW, 77.8% versus 66.7%. Liver cancer incidence rates among AI/AN males and females were higher than those among NHW males and females for all regions except for the East. Among males, rates ranged from 7.3 (95% confidence interval [CI], 3.8-12.6) in the East to 17.2 (95% CI, 10.4-26.3) in Alaska. Among females, rates ranged from 3.8 (95% CI, 1.4-8.2) in the East to 6.9 (95% CI, 3.6-11.6) in Alaska. The AI/AN rates for all regions were consistently higher than the NHW rates at every age. An increasing trend among AI/AN was suggested but did not achieve statistical significance. CONCLUSIONS: Reducing racial misclassification revealed higher disparities in primary liver cancer incidence between NHW and AI/AN populations than previously reported. Further description of the reasons for regional differences in this disparity is needed, as are programs to reduce risk factors and to diagnose primary liver cancer at earlier, more treatable stages.

Gallbladder cancer incidence among American Indians and Alaska Natives, US, 1999-2004.

BACKGROUND: Gallbladder cancer (GBC) is rare; however, it disproportionately affects the American Indian and Alaska Natives (AI/AN) population. The purpose of the study was to characterize GBC among AI/AN in the US population. METHODS: Cases of GBC diagnosed between 1999 and 2004 and collected by state-based cancer registries were included. Registry records were linked with Indian Health Service (IHS) administration records to decrease race misclassification of AI/AN. GBC rates and/or percent distributions for AI/AN and non-Hispanic whites (NHW) were calculated by sex, IHS region, age, and stage for all US counties and IHS Contract Health Service Delivery Area (CHSDA) counties, in which approximately 56% of US AI/AN individuals reside. RESULTS: In CHSDA counties, the GBC incidence rate among AI/AN was 3.3 per 100,000, which was significantly higher than that among NHW (P < .05). Rates varied widely among IHS regions and ranged from 1.5 in the East to 5.5 in Alaska. Rates were higher among AI/AN females than males in all regions, except the Northern Plains. Higher percentages of GBC were diagnosed among AI/AN aged <65 years compared with NHW. GBC was most often diagnosed at the regional stage among AI/AN, whereas GBC was most often diagnosed at regional or distant stages among NHW. CONCLUSIONS: To the authors' knowledge to date, this is the most comprehensive study of GBC incidence among AI/AN in the US. The accurate characterization of GBC in this population could help inform the development of interventions aimed at reducing morbidity and mortality from this disease.

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

BACKGROUND: Colorectal cancer (CRC) is a leading cause of cancer morbidity and mortality for American Indians and Alaska Natives (AI/ANs), but misclassification of race causes underestimates of disease burden. METHODS: The authors compared regional differences in CRC incidence, stage at diagnosis, and anatomic distribution between AI/ANs and non-Hispanic whites (NHWs). To reduce misclassification, data from the National Program of Cancer Registries; the Surveillance, Epidemiology, and End Results Program; and the Indian Health Service (IHS) were linked. The analysis was limited to the 56% of AI/AN who live in IHS Contract Health Service Delivery Areas. RESULTS: From 1999 to 2004, the overall incidence rate (per 100,000 persons per year) of CRC was 9% lower in the AI/AN population (46.3) than in the NHW population (50.8). However, AI/AN CRC incidence rates varied nearly 5-fold regionally, from 21 in the Southwest to 102.6 in Alaska. Compared with NHW rates, AI/AN rates were significantly higher in Alaska (rate ratio [RR], 2.03), the Northern Plains (RR, 1.39), and the Southern Plains (RR, 1.16) but were lower in the Pacific Coast (RR, 0.80), the East (RR, 0.65), and the Southwest (RR, 0.45). AI/ANs were diagnosed more often with advanced CRC than with localized CRC (RR, 1.92) compared with NHWs (RR, 1.48). Females more often had proximal CRC among both the AI/AN population (females, 40.1%; males, 33.5%) and the NHW population (females, 50.1%; males, 40.3%), although AI/ANs had a higher proportion of distal cancers overall. CONCLUSIONS: CRC incidence rates in AI/AN populations varied dramatically between regions. Efforts are needed to make CRC screening a priority, overcome barriers to endoscopic screening, and to engage AI/AN communities in culturally appropriate ways to participate in prevention and early detection programs.