Research Priorities for Interventions to Address Health Disparities in Lung Nodule Management: An Official American Thoracic Society Research Statement

Background: Lung nodules are common incidental findings, and timely evaluation is critical to ensure diagnosis of localized-stage and potentially curable lung cancers. Rates of guideline-concordant lung nodule evaluation are low, and the risk of delayed evaluation is higher for minoritized groups. Objectives: To summarize the existing evidence, identify knowledge gaps, and prioritize research questions related to interventions to reduce disparities in lung nodule evaluation. Methods: A multidisciplinary committee was convened to review the evidence and identify key knowledge gaps in four domains: 1) research methodology, 2) patient-level interventions, 3) clinician-level interventions, and 4) health system-level interventions. A modified Delphi approach was used to identify research priorities. Results: Key knowledge gaps included 1) a lack of standardized approaches to identify factors associated with lung nodule management disparities, 2) limited data evaluating the role of social determinants of health on disparities in lung nodule management, 3) a lack of certainty regarding the optimal strategy to improve patient-clinician communication and information transmission and/or retention, and 4) a paucity of information on the impact of patient navigators and culturally trained multidisciplinary teams. Conclusions: This statement outlines a research agenda intended to stimulate high-impact studies of interventions to mitigate disparities in lung nodule evaluation. Research questions were prioritized around the following domains: 1) need for methodologic guidelines for conducting research related to disparities in nodule management, 2) evaluating how social determinants of health influence lung nodule evaluation, 3) studying approaches to improve patient-clinician communication, and 4) evaluating the utility of patient navigators and culturally enriched multidisciplinary teams to reduce disparities.

Amplifying Their Voices: Advice, Guidance, and Perceived Value of Cancer Biobanking Research Among an Older, Diverse Cohort

The use of biobanks may accelerate scientists' chances of developing cures and treatments that are tailored to individuals' biological makeup-a function of the precision medicine movement. However, given the underrepresentation of certain populations in biobanks, the benefits of these resources may not be equitable for all groups, including older, multi-ethnic populations. The objective of this study was to better understand older, multi-ethnic populations' (1) perceptions of the value of cancer biobanking research, (2) study design preferences, and (3) guidance on ways to promote and increase participation. This study was designed using a community-based participatory research (CBPR) approach and involved eight FGDs with 67 older (65-74 years old) black and white residents from Baltimore City and Prince George's County, MD. FGDs lasted between 90 and 120 min, and participants received a $25 Target gift card for their participation. Analysis involved an inductive approach in which we went through a series of open and axial coding techniques to generate themes and subthemes. Multiple themes emerged from the FGDs for the development of future cancer-related biobanking research including (1) expectations/anticipated benefits, (2) biobanking design preferences, and (3) ways to optimize participation. Overall, most participants were willing to provide biospecimens and favored cancer-related biobank. To increase participation of older, diverse participants in biobanking protocols, researchers need to engage older, diverse persons as consultants in order to better understand the value of biobanking research to individuals from the various populations. Scientists should also incorporate suggestions from the community on garnering trust and increasing comfort with study design.

Abstract A096: Smartphone use and accessibility to Internet by cancer patients in a socioeconomically diverse community

Introduction: Hospitals are increasingly using different patient engagement platforms to improve patient education, engagement, and satisfaction. Most of these patient engagement platforms are smartphone based. This requires patient awareness and understanding of basic technology. Einstein Medical Center serves a large socioeconomically and racially diverse population in North Philadelphia. We undertook a feasibility study before introducing any patient education/engagement platforms in our population. Our primary objective was to assess the use of smartphones and Internet by cancer patients in a socioeconomically diverse population. Our secondary objective was to assess feasibility of introducing technological platforms to improve patient education, engagement and satisfaction.

Methods: A onetime cross-sectional survey of patients attending the outpatient clinic and infusion center were interviewed by a trained interviewer during a one-week period in July 2018. The questionnaire was designed to assess demographic information, questions related to patients' smartphone and Internet availability, and use for health.

Results: We surveyed 75 patients in one week (N=75). Their ages ranged from 21 to 91 years old. There were 25 (33.3%) male and 50 (66.7%) female patients. Around 32 patients had at least a college education and 42 had a high school level education or less. 53 (71.6%) patients owned a smartphone and all of those owners could browse the Internet and download applications on their phone. 20 (26.67%) patients used an iPhone platform and 34 (45.33%) patients used an Android smartphone. Most of the patients who had a smartphone were willing to download applications that can help monitor their cancer and health.

Conclusion: Though our hospital is located in a socioeconomically disadvantaged area, the vast majority of patients own a smartphone and are willing to use them to monitor their cancer care. We can confidently use this technological advancement to help improve patient education, engagement, and satisfaction in this setting.

Note: This abstract was not presented at the conference.

Citation Format: Rashmika R. Potdar, Arun Thomas, Claudia Dourado, Kamran Mohiuddin, Djeneba Audrey M. Djibo, John C. Leighton, Jean G. Ford. Smartphone use and accessibility to Internet by cancer patients in a socioeconomically diverse community [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A096.

The effect of aspirin on colorectal cancer incidence in African Americans

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Background: From 2011 to 2016, the incidence and mortality rate of colorectal cancer(CRC) were highest among African Americans(AA), compared to other US racial/ethnic groups. Long-term aspirin use is recommended as a strategy to reduce the risk of CRC. Yet, there is scant information on the chemopreventive effect of aspirin among AA. It is imperative to assess whether the reported chemo-preventive effect also occurs in AA. Our central hypothesis is that aspirin use in AA is associated with a lower incidence of CRC, irrespective of race/ethnicity. Methods: We conducted a secondary analysis, using data from AA participants in the Atherosclerosis Risk in Communities(ARIC) longitudinal study, who did not have CRC at enrollment, from 1987 to 1998. We extracted demographic, clinical and mortality data to compare the incidence of CRC among participants taking aspirin compared to those who were not taking aspirin, stratified by age, tobacco use, and body mass index. All-cause mortality and CRC mortality will also be assessed, and we will use Cox proportional hazard regression to determine the relationship between aspirin use and CRC incidence, and mortality. Results: At baseline in 1987, 15,026 participants enrolled in the ARIC study, 25% of whom were AA, median age 54(range 44-66), including 46.7% who reported using aspirin. We analyzed follow-up data from 10,960 participants in 1996-1998, 20% of whom were AA, and 56.9% of whom were taking aspirin. Non-AA participants were more likely to report using aspirin at baseline and follow-up, compared to AA, 53% vs 30% and 59% vs 50% respectively. After 10years, the total incidence of CRC in AA participants was 1% compared with 1.1% in non-AA(p = 0.7). There was no difference in CRC incidence by aspirin use among all participants, and when stratified by race(among all participants p = 0.81, amongAA p = 0.68, among non-AA p = 0.94). Conclusions: We found no difference in the incidence of CRC among AA compared to Caucasians, by aspirin use. Investigation of consistency and/or dose of aspirin use by race may provide further insights on the relationship between aspirin use and CRC incidence, comparing AA to Caucasians.

Access to internet, smartphone usage, and acceptability of mobile health technology among cancer patients

PURPOSE

The use of mobile health (mHealth) technologies to augment patient care enables providers to communicate remotely with patients enhancing the quality of care and patient engagement. Few studies evaluated predictive factors of its acceptance and subsequent implementation, especially in medically underserved populations.

METHODS

A cross-sectional study of 151 cancer patients was conducted at an academic medical center in the USA. A trained interviewer performed structured interviews regarding the barriers and facilitators of patients' current and desired use of mHealth technology for healthcare services.

RESULTS

Of the 151 participants, 35.8% were male and ages ranged from 21 to 104 years. 73.5% of participants currently have daily access to internet, and 68.2% currently own a smartphone capable of displaying mobile applications. Among all participants, acceptability of a daily mHealth application was significantly higher in patients with a college-level degree (OR 2.78, CI_95% 1.25-5.88) and lower in patients > 80 years of age (OR 0.05, CI_95% 0.01-0.23). Differences in acceptability when adjusted for current smartphone use and daily access to internet were nonsignificant. Among smartphone users, the desire to increase cancer knowledge was associated with a higher likelihood of utilizing a mHealth application (OR 261.53, CI_95% 10.13-6748.71).

CONCLUSION

The study suggests that factors such as age, educational achievement, and access to internet are significant predictors of acceptability of a mHealth application among cancer patients. Healthcare organizations should consider these factors when launching patient engagement platforms.

Prevalence of disability among adults with chronic obstructive pulmonary disease, Behavioral Risk Factor Surveillance System 2016-2017

BACKGROUND

The prevalence of disabilities is rising steadily, reflecting an aging population and an increasing burden of chronic conditions affecting quality of life. There are scant national data on the prevalence of disability among individuals with chronic obstructive pulmonary disease (COPD). The main objective was to estimate the prevalence of common disabilities among US-based individuals diagnosed with COPD.

METHODS

Data from the BRFSS, a national telephone survey examining health-related behaviors in 2016-2017 were analyzed. The study population consisted of individuals with self-reported COPD (N = 38352 in 2016 and N = 35423 in 2017). The prevalence of disabilities in hearing, vision, cognition, mobility, and independent living were obtained and adjusted with sampling weights. Healthcare access measures were described by type of disability.

RESULTS

Mobility disability had the highest prevalence of 45.9 (44.8-47.0) % in 2016 and 48.4 (47.3-49.5) % in 2017 among respondents with COPD. The prevalence of disabilities was highest among those 45-64 years old, except for hearing and cognition. Hearing disabilities were most prevalent among males with COPD while cognitive and mobility disabilities were most prevalent among females with COPD. While differences in the prevalence of disabilities were observed, access to health care was similar by disability type and age group among respondents.

CONCLUSION

Contrary to expectation, the highest prevalence of disabilities was found not to be among those 65 years old and above. Further research is needed to explain this age-specific shift in the burden of disability, as long-term care planning and prevention support systems should be informed by the demographical patterns of disabilities among individuals with COPD.

Association Between the Timing of Goals-of-Care Discussion and Hospitalization Outcomes in Patients With Metastatic Cancer

BACKGROUND

Patients with cancer often require acute hospitalizations, many of which are unplanned. These hospitalizations have been shown to increase in frequency near the end of life. The American College of Physicians recommends that goals-of-care (GOC) discussions be initiated early for metastatic cancers. We hypothesized that discussing GOC during hospitalization could help reduce readmissions. Our aim was to examine the association between the timing of GOC discussion, length of hospital stay, and the time to readmission.

METHODS

We conducted a retrospective review of medical records of patients with stage IV cancers hospitalized between August 2017 and July 2018. We recorded timing of GOC discussion, use of palliative care services, and hospital readmissions within 90 days. χ² tests were used to identify independent associations with GOC discussion, and logistic regression was used to examine association with readmission within 90 days.

RESULTS

Of all study patients (N = 241), 40.6% were female, 46% (n = 112) had a GOC discussion, and 34% (n = 82) had a palliative care consultation. Having a palliative care consult and being admitted to critical care were independently associated with having a GOC discussion. Early timing of GOC discussion was inversely associated with admission to critical care units (P < .05). Thirty-eight percent (n = 92) had unplanned hospital readmission within 90 days. Having a GOC discussion was independently associated with a reduction in the odds of an unplanned hospital readmission within 90 days by 79% (odds ratio = 0.21, 95% confidence interval: 0.12-0.37).

CONCLUSION

Among hospitalized patients with stage IV cancer, performing an early GOC discussion has an important association with lower hospital readmission rates and increased rates of goal-congruent patient care.

Influence of timing of goals of care discussion on hospitalization outcomes in metastatic cancer patients

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Background: Cancer patients often require acute hospitalizations, and these hospitalizations have been shown to increase in frequency near the end of life. The American College of Physicians recommends that goals of care (GOC) discussions be initiated early for metastatic cancers. Discussing GOC during hospitalization can help reduce readmissions and improve patient satisfaction, by helping to ensure that patients receive goal-congruent care. We aim to examine the association between the timing of GOC discussion and the patient's length of stay and the time to hospital readmission. Methods: We conducted a retrospective review of medical records of patients with stage IV solid tumors who were hospitalized acutely between August 2017 and July 2018. We assessed demographics, timing of GOC discussion, use of palliative care services and hospital readmissions within 90 days. Chi-square tests were used to identify independent associations with having a GOC discussion; and anova was used for continuous variables. We used logistic regression to examine the association with a hospital readmission within 90 days, controlling for potential confounders. Results: The subjects were 26-92 years old and 40.6% were female. Only 46% (n = 112) of patients had a GOC discussion. Age, tumor site, and presenting complaint were not independently associated with having a GOC discussion (p > 0.05). Overall, 34% (n = 82) had a palliative care encounter. Having a palliative care consult and being admitted to critical care were independently associated with having a GOC discussion. Early timing of GOC discussion was inversely associated with admission to critical care units (p < 0.05). Length of stay was positively correlated with having a GOC discussion. Thirty-eight percent (n = 92) had unplanned hospital readmission within 90 days. Having any GOC discussion reduced the odds of an unplanned hospital readmission within 90 days by 79% [OR = 0.21, 95% confidence interval 0.12-0.37]. Conclusions: Among hospitalized patients with stage IV cancer, performing an early GOC discussion is associated with better hospitalization outcomes. It is therefore important to perform GOC discussion early when such patients are acutely hospitalized.

Influence of timing of goals of care discussion on hospitalization outcomes in metastatic cancer patients

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Background: Cancer patients often require acute hospitalizations, many of which are unplanned. These hospitalizations have been shown to increase in frequency near the end of life. The American College of Physicians recommends that goals of care (GOC) discussions be initiated early for metastatic cancers. We hypothesize that discussing GOC during hospitalization will help reduce readmissions and improve patient satisfaction, by helping to ensure that patients receive goal-congruent care. We aim to examine the association between the timing of GOC discussion and the patient's length of stay and the time to hospital readmission. Methods: We conducted a retrospective review of medical records of patients with stage IV solid tumors who were hospitalized acutely between August 2017 and July 2018 (N = 241). We assessed demographics, clinical information, timing of GOC discussion, use of palliative care services and hospital readmissions within 90 days. Chi-square tests were used to identify independent associations with having a GOC discussion; and anova was used for continuous variables. We used logistic regression to examine the association with a hospital readmission within 90 days, controlling for potential confounders. Results: The subjects were 26-92 years old and 40.6% were female. Only 43% (n = 106) of patients had a GOC discussion. Age, gender, tumor site, and presenting complaint were not independently associated with having a GOC discussion (p > 0.05). Overall, 34.4% (n = 83) had a palliative care encounter. Having a palliative care consult and being admitted to critical care were independently associated with having a GOC discussion. Early timing of GOC discussion was inversely associated with admission to critical care units (p < 0.05). Length of stay was positively correlated with having a GOC discussion. Thirty-seven percent (n = 91) had unplanned hospital readmission within 90 days. Having any GOC discussion reduced the odds of an unplanned hospital readmission within 90 days by 75% [OR = 0.25, 95% confidence interval (CI) 0.14-0.45]. Conclusions: Among hospitalized patients with stage IV cancer, performing an early GOC discussion is associated with better hospitalization outcomes. It is therefore important to perform GOC discussion early when such patients are acutely hospitalized.

Acceptability of mobile health technology among cancer patients

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Background: Advances in wireless technology have led to the increasing use of mobile health platforms. This approach, tele-medicine, enables healthcare providers to communicate remotely with patients, thereby enhancing timeliness and quality of care, and patient engagement. However, few studies address barriers to its implementation, especially in medically under served populations. Methods: A cross-sectional survey of 151 cancer patients was conducted at an academic medical center in North Philadelphia, PA. A trained interviewer performed structured interviews regarding the barriers and facilitators of patients’ current and desired utilization of technology for healthcare services. Statistical significance was defined as p < 0.05 on a two-tailed distribution. Chi-Square test was used for categorical variables. Odds ratios from logistic regression analysis were used to identify the relationship between demographic factors and willingness to utilize a mobile application for health surveillance. Results: Of the 151 patients who completed the survey, 35.8% were male; ages ranged from 21-104 years. Forty-two percent were married, 49.0% were single, and 9% were divorced at the time of the survey. No significant associations existed between the willingness to utilize a mobile health application and gender ( p = 0.73) or marital status ( p = 0.97). After controlling for other demographic variables, patients older than 70 were significantly less likely to utilize a mobile application. Conversely, patients with a college-level education or more were significantly more likely to utilize a mobile application [OR = 2.78, p = 0.01]. Conclusions: Age and education level represent potential barriers to mobile health applications for cancer patients in socioeconomically diverse community. Health networks should consider these factors when launching patient engagement platforms. [Table: see text]

Community Engagement to Address Cancer Health Disparities: A Process EVALUATION using the Partnership Self-Assessment Tool

BACKGROUND

African Americans suffer disproportionately from cancer health disparities, and population-level prevention is needed.

OBJECTIVES

A community-academic partnership to address cancer health disparities in two predominately African American jurisdictions in Maryland was evaluated.

METHODS

The Partnership Self-Assessment Tool (PSAT) was used in a process evaluation to assess the partnership in eight domains (partnership synergy, leadership, efficiency, management, resources, decision making, participation, and satisfaction).

RESULTS

Mean scores in each domain were high, indicative of a functional and synergistic partnership. However, scores for decision making (Baltimore City's mean score = 9.3; Prince George's County's mean score = 10.8; p = .02) and participation (Baltimore City's mean score = 16.0; Prince George's County's mean score = 18.0; p = .04) were significantly lower in Baltimore City.

CONCLUSIONS

Community-academic partnerships are promising approaches to help address cancer health disparities in African American communities. Factors that influence decision making and participation within partnerships require further research.

Author Correction: Assembly of a pan-genome from deep sequencing of 910 humans of African descent

In the version of this article initially published, the statement "there are no pan-genomes for any other animal or plant species" was incorrect. The statement has been corrected to "there are no reported pan-genomes for any other animal species, to our knowledge." We thank David Edwards for bringing this error to our attention. The error has been corrected in the HTML and PDF versions of the article.

A genome-wide association and admixture mapping study of bronchodilator drug response in African Americans with asthma

Short-acting β₂-adrenergic receptor agonists (SABAs) are the most commonly prescribed asthma medications worldwide. Response to SABAs is measured as bronchodilator drug response (BDR), which varies among racial/ethnic groups in the U.S^{1, 2}. However, the genetic variation that contributes to BDR is largely undefined in African Americans with asthma³. To identify genetic variants that may contribute to differences in BDR in African Americans with asthma, we performed a genome-wide association study (GWAS) of BDR in 949 African American children with asthma, genotyped with the Axiom World Array 4 (Affymetrix, Santa Clara, CA) followed by imputation using 1000 Genomes phase III genotypes. We used linear regression models adjusting for age, sex, body mass index (BMI) and genetic ancestry to test for an association between BDR and genotype at single nucleotide polymorphisms (SNPs). To increase power and distinguish between shared vs. population-specific associations with BDR in children with asthma, we performed a meta-analysis across 949 African Americans and 1,830 Latinos (Total=2,779). Lastly, we performed genome-wide admixture mapping to identify regions whereby local African or European ancestry is associated with BDR in African Americans. We identified a population-specific association with an intergenic SNP on chromosome 9q21 that was significantly associated with BDR (rs73650726, p=7.69×10⁻⁹). A trans-ethnic meta-analysis across African Americans and Latinos identified three additional SNPs within the intron of PRKG1 that were significantly associated with BDR (rs7903366, rs7070958, and rs7081864, p≤5×10⁻⁸). Our results failed to replicate in three additional populations of 416 Latinos and 1,615 African Americans. Our findings indicate that both population specific and shared genetic variation contributes to differences in BDR in minority children with asthma, and that the genetic underpinnings of BDR may differ between racial/ethnic groups.

Breastfeeding associated with higher lung function in African American youths with asthma

OBJECTIVE

In the United States, Puerto Ricans and African Americans have lower prevalence of breastfeeding and worse clinical outcomes for asthma compared with other racial/ethnic groups. We hypothesize that the history of breastfeeding is associated with increased forced expiratory volume in 1 second (FEV1) % predicted and reduced asthma exacerbations in Latino and African American youths with asthma.

METHODS

As part of the Genes-environments & Admixture in Latino Americans (GALA II) Study and the Study of African Americans, asthma, Genes & Environments (SAGE II), we conducted case-only analyses in children and adolescents aged 8-21 years with asthma from four different racial/ethnic groups: African Americans (n = 426), Mexican Americans (n = 424), mixed/other Latinos (n = 255), and Puerto Ricans (n = 629). We investigated the association between any breastfeeding in infancy and FEV1% predicted using multivariable linear regression; Poisson regression was used to determine the association between breastfeeding and asthma exacerbations.

RESULTS

Prevalence of breastfeeding was lower in African Americans (59.4%) and Puerto Ricans (54.9%) compared to Mexican Americans (76.2%) and mixed/other Latinos (66.9%; p < 0.001). After adjusting for covariates, breastfeeding was associated with a 3.58% point increase in FEV1% predicted (p = 0.01) and a 21% reduction in asthma exacerbations (p = 0.03) in African Americans only.

CONCLUSION

Breastfeeding was associated with higher FEV1% predicted in asthma and reduced number of asthma exacerbations in African American youths, calling attention to continued support for breastfeeding.

A continuum of admixture in the Western Hemisphere revealed by the African Diaspora genome

The African Diaspora in the Western Hemisphere represents one of the largest forced migrations in history and had a profound impact on genetic diversity in modern populations. To date, the fine-scale population structure of descendants of the African Diaspora remains largely uncharacterized. Here we present genetic variation from deeply sequenced genomes of 642 individuals from North and South American, Caribbean and West African populations, substantially increasing the lexicon of human genomic variation and suggesting much variation remains to be discovered in African-admixed populations in the Americas. We summarize genetic variation in these populations, quantifying the postcolonial sex-biased European gene flow across multiple regions. Moreover, we refine estimates on the burden of deleterious variants carried across populations and how this varies with African ancestry. Our data are an important resource for empowering disease mapping studies in African-admixed individuals and will facilitate gene discovery for diseases disproportionately affecting individuals of African ancestry.

Effectiveness of strategies to recruit underrepresented populations into cancer clinical trials

Background Certain populations, including racial and ethnic minorities and older persons, have had a history of low participation in cancer-related trials, yet there has been little information reported on recruitment strategies tailored to improve their enrollment.

Methods We conducted a systematic literature review to examine the methods used to study recruitment of underrepresented populations into cancer prevention and treatment trials and examined the studies that compared the efficacy and/or effectiveness of different recruitment strategies. We performed an electronic search through multiple databases including PubMed and a hand search of 34 journals. Potential studies were pulled and underwent title, abstract, and article review by at least two investigators.

Results Fourteen articles examined recruitment of underrepresented populations into cancer trials and, of these, five compared efficacy or effectiveness of different strategies for recruitment of underrepresented populations into randomized or concurrent controlled trials. These five studies used various strategies but only three reported that specific recruitment strategies, such as media campaigns and churchbased project sessions, resulted in improvement in accrual to cancer trials.

Conclusion There is limited evidence for efficacious or effective strategies to recruit underrepresented populations in cancer-related trials. The available evidence cannot be generalized to these heterogeneous groups. Further study is needed on efficacious strategies for recruitment of underrepresented populations into cancerrelated trials.

Applying justice in clinical trials for diverse populations

Background Considerable attention has focused on increasing clinical trial participation for members of “underrepresented groups”. However, doing so involves clarifying how to meet the demands of justice, or fairness, which provides the ethical mandate to enhance broad trial representation.

Purpose To examine the ethical principle of justice as it applies to recruiting diverse populations to clinical trials representation.

Methods In this paper, we analyse the conceptual and practical challenges in applying the principle of justice to clinical trials representation.

Results Different facets of justice include demands for both fair outcomes and fair processes. Including both of these facets in clinical trials policy should not only promote access to trials, but also help to provide a framework to improve fairness in representation in clinical trials. Efforts to evaluate recruitment of representation should include outcome and process measures.

Limitations The suggestions offered based on this conceptual analysis need to be tested empirically.

Conclusions Those involved in the design, conduct and oversight of clinical trials should consider all of the facets of justice when assessing representation in clinical trials and attempt to balance fair access to trials with a fair process that may require protection from being unduly pressured to participate. Clinical Trials 2007; 4: 264—269; http://ctj.sagepub.com

A critical review of the enrollment of black patients in cancer clinical trials

Although clinical trials represent a vital opportunity for improvements in cancer treatment, data show that a small proportion of patients with newly diagnosed cancer participate in clinical research. Black patients continue to have a worse prognosis for most cancers compared with other patients of other races/ethnicities. Racial/ethnic- and age-related disparities in clinical trial accrual are also well documented. The recruitment and retention of minorities in these trials present an even greater challenge despite regulatory efforts and initiatives to increase representation. Treatment data from homogenous populations prevent us from understanding therapeutic response and the true safety profile of novel therapies. Patient-, physician-, and system-level factors that affect trial participation have been extensively studied. However, years of accrual data remain largely unchanged, suggesting the challenge lies in effectively addressing these factors. Furthermore, data showing that black patients tend to have more advanced stage cancers at the time of diagnosis in fact beg their overrepresentation on clinical trials. An inability to successfully enroll diverse populations in clinical trials only exacerbates racial/ethnic differences in cancer treatment and survivorship.

Effect of Patient Navigation on Breast Cancer Screening Among African American Medicare Beneficiaries: A Randomized Controlled Trial

BACKGROUND

There is growing evidence that patient navigation improves breast cancer screening rates; however, there are limited efficacy studies of its effect among African American older adult women.

OBJECTIVE

To evaluate the effect of patient navigation on screening mammography among African American female Medicare beneficiaries in Baltimore, MD.

DESIGN

The Cancer Prevention and Treatment Demonstration (CPTD), a multi-site study, was a randomized controlled trial conducted from April 2006 through December 2010.

SETTING

Community-based and clinical setting.

PARTICIPANTS

The CPTD Screening Trial enrolled 1905 community-dwelling African American female Medicare beneficiaries who were ≥65 years of age and resided in Baltimore, MD. Participants were recruited from health clinics, community centers, health fairs, mailings using Medicare rosters, and phone calls.

INTERVENTIONS

Participants were randomized to either: printed educational materials on cancer screening (control group) or printed educational materials + patient navigation services designed to help participants overcome barriers to cancer screening (intervention group).

MAIN MEASURE

Self-reported receipt of mammography screening within 2 years of the end of the study.

KEY RESULTS

The median follow-up period for participants in this analysis was 17.8 months. In weighted multivariable logistic regression analyses, women in the intervention group had significantly higher odds of being up to date on mammography screening at the end of the follow-up period compared to women in the control group (odds ratio [OR] 2.26, 95 % confidence interval [CI]1.59-3.22). The effect of the intervention was stronger among women who were not up to date with mammography screening at enrollment (OR 3.63, 95 % CI 2.09-6.38).

CONCLUSION

Patient navigation among urban African American Medicare beneficiaries increased self-reported mammography utilization. The results suggest that patient navigation for mammography screening should focus on women who are not up to date on their screening.

Mobilizing social support networks to improve cancer screening: the COACH randomized controlled trial study design

BACKGROUND

Disadvantaged populations face many barriers to cancer care, including limited support in navigating through the complexities of the healthcare system. Family members play an integral role in caring for patients and provide valuable care coordination; however, the effect of family navigators on adherence to cancer screening has not previously been evaluated. Training and evaluating trusted family members and other support persons may improve cancer outcomes for vulnerable patients.

METHODS

Guided by principles of community based participatory research (CBPR), "Evaluating Coaches of Older Adults for Cancer Care and Healthy Behaviors (COACH)" is a community-based randomized controlled trial to assess the effectiveness of a trained participant-designated coach (support person or care giver) in navigating cancer-screening for older African American adults, 50-74 years old. Participants are randomly assigned as dyads (participant+coach pair) to receiving either printed educational materials only (PEM--control group) or educational materials plus coach training (COACH--intervention group). We defined a coach as family member, friend, or other lay support person designated by the older adult. The coach training is designed as a one-time, 35- to 40-minute training consisting of: 1) a didactic session that covers the role of the coach, basic facts about colorectal, breast and cervical cancers (including risk factors, signs and symptoms and screening modalities), engaging the healthcare provider in cancer screening, insurance coverage for screening, and related healthcare issues, 2) three video skits addressing misconceptions about and planning for cancer screening, and 3) an interactive role-play session with the trainer to reinforce and practice strategies for encouraging the participant to get screened. The primary study outcome is the difference in the proportion of participants completing at least one of the recommended screenings (for breast, cervix or colorectal cancer) between the control and intervention groups.

DISCUSSION

Building on trusted patient contacts to encourage cancer screening, COACH is a highly sustainable intervention in a high-risk population. It has the potential to minimize the effect of mistrust of the medical establishment on screening behaviors by mobilizing participants' existing support networks. If effective, the intervention could have a high impact on health care disparities research across multiple diseases.

TRIAL REGISTRATION

ClinicalTrials.gov ( NCT01613430 ). Registered June 5, 2012.

Abstract A96: African Americans and colorectal cancer: Using multilevel analysis to understand the influence of neighborhood and individual level factors on screening behavior

Background: Early detection of colorectal cancer (CRC) effectively prevents premature deaths. However, racial disparities in CRC persist due to underutilization of cancer screening, which is associated with late stage diagnosis and higher mortality rates among African Americans. It is well documented that “…individual behavior both influences and is influenced by the social and physical environment…” Interventions that incorporate the environmental context of the individual behavior are more associated with increasing CRC screening. Methods: Using a community-engaged approach we recruited 230 African American adults aged 50 to 74 years to complete a psychosocial survey. Participants were recruited from a variety of venues, including churches, barbershops, community centers and public housing complexes in the Washington, DC Metropolitan Area. The survey instrument included valid standardized scales designed to assess 1) knowledge of cancer, 2) risk perception, 3) neighborhood perceptions, 4) social support, 5) behavioral risk factors, 6) religiousness and 7) trust in research. Results: Participants were women (80%), married (39%) and low income (34%). Preliminary analysis demonstrated that participants who were midlife (&lt; 60 years of age), unmarried, unemployed and reported no medical home were less likely to be screened for CRC (p&lt;0.01). Additionally, subscale measures for neighborhood perceptions, “social cohesion” (p&lt;0.04) and CRC knowledge were also significantly associated with receiving a CRC screening (p&lt;0.001). Additional analyses (multilevel modeling) are underway, using census data. Conclusions: Understanding the combined effects of individual and neighborhood factors may contribute to the development of scientifically sound and culturally relevant interventions to increase CRC screening among African Americans.

Citation Format: Mary A. Garza, Luciana C. Assini, Gabriella Villacis, Jean G. Ford. African Americans and colorectal cancer: Using multilevel analysis to understand the influence of neighborhood and individual level factors on screening behavior. [abstract]. In: Proceedings of the Seventh AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 9-12, 2014; San Antonio, TX. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2015;24(10 Suppl):Abstract nr A96.

Effect of patient navigation on colorectal cancer screening in a community-based randomized controlled trial of urban African American adults

PURPOSE

In recent years, colorectal cancer (CRC) screening rates have increased steadily in the USA, though racial and ethnic disparities persist. In a community-based randomized controlled trial, we investigated the effect of patient navigation on increasing CRC screening adherence among older African Americans.

METHODS

Participants in the Cancer Prevention and Treatment Demonstration were randomized to either the control group, receiving only printed educational materials (PEM), or the intervention arm where they were assigned a patient navigator in addition to PEM. Navigators assisted participants with identifying and overcoming screening barriers. Logistic regression analyses were used to assess the effect of patient navigation on CRC screening adherence. Up-to-date with screening was defined as self-reported receipt of colonoscopy/sigmoidoscopy in the previous 10 years or fecal occult blood testing (FOBT) in the year prior to the exit interview.

RESULTS

Compared with controls, the intervention group was more likely to report being up-to-date with CRC screening at the exit interview (OR 1.55, 95 % CI 1.07-2.23), after adjusting for select demographics. When examining the screening modalities separately, the patient navigator increased screening for colonoscopy/sigmoidoscopy (OR 1.53, 95 % CI 1.07-2.19), but not FOBT screening. Analyses of moderation revealed stronger effects of navigation among participants 65-69 years and those with an adequate health literacy level.

CONCLUSIONS

In a population of older African Americans adults, patient navigation was effective in increasing the likelihood of CRC screening. However, more intensive navigation may be necessary for adults over 70 years and individuals with low literacy levels.

Genome-wide association study and admixture mapping reveal new loci associated with total IgE levels in Latinos

BACKGROUND

IgE is a key mediator of allergic inflammation, and its levels are frequently increased in patients with allergic disorders.

OBJECTIVE

We sought to identify genetic variants associated with IgE levels in Latinos.

METHODS

We performed a genome-wide association study and admixture mapping of total IgE levels in 3334 Latinos from the Genes-environments & Admixture in Latino Americans (GALA II) study. Replication was evaluated in 454 Latinos, 1564 European Americans, and 3187 African Americans from independent studies.

RESULTS

We confirmed associations of 6 genes identified by means of previous genome-wide association studies and identified a novel genome-wide significant association of a polymorphism in the zinc finger protein 365 gene (ZNF365) with total IgE levels (rs200076616, P = 2.3 × 10(-8)). We next identified 4 admixture mapping peaks (6p21.32-p22.1, 13p22-31, 14q23.2, and 22q13.1) at which local African, European, and/or Native American ancestry was significantly associated with IgE levels. The most significant peak was 6p21.32-p22.1, where Native American ancestry was associated with lower IgE levels (P = 4.95 × 10(-8)). All but 22q13.1 were replicated in an independent sample of Latinos, and 2 of the peaks were replicated in African Americans (6p21.32-p22.1 and 14q23.2). Fine mapping of 6p21.32-p22.1 identified 6 genome-wide significant single nucleotide polymorphisms in Latinos, 2 of which replicated in European Americans. Another single nucleotide polymorphism was peak-wide significant within 14q23.2 in African Americans (rs1741099, P = 3.7 × 10(-6)) and replicated in non-African American samples (P = .011).

CONCLUSION

We confirmed genetic associations at 6 genes and identified novel associations within ZNF365, HLA-DQA1, and 14q23.2. Our results highlight the importance of studying diverse multiethnic populations to uncover novel loci associated with total IgE levels.

The Relationship Between Education and Prostate-Specific Antigen Testing Among Urban African American Medicare Beneficiaries

PURPOSE

We examined the association between socioeconomic status (SES) and prostate-specific antigen (PSA) cancer screening among older African American men.

METHODS

We analyzed baseline data from a sample of 485 community-dwelling African American men who participated in the Cancer Prevention and Treatment Demonstration Trial. The outcome was receipt of PSA screening within the past year. SES was measured using income and educational attainment. Sequential multivariate logistic regression models were performed to study whether health care access, patient-provider relationship, and cancer fatalism mediated the relationship between SES and PSA screening.

RESULTS

Higher educational attainment was significantly associated with higher odds of PSA screening in the past year (odds ratio (OR) 2.08 for college graduate compared to less than high school graduate, 95 % confidence interval (CI) 1.03-4.24); income was not. Health care access and patient-provider communication did not alter the relationship between education and screening; however, beliefs regarding cancer fatalism partially mediated the observed relationship.

CONCLUSION

Rates of prostate cancer screening among African American men vary by level of educational attainment; beliefs concerning cancer fatalism help explain this gradient. Understanding the determinants of cancer fatalism is a critical next step in building interventions that seek to ensure equitable access to prostate cancer screening.

Genetic ancestry influences asthma susceptibility and lung function among Latinos

BACKGROUND

Childhood asthma prevalence and morbidity varies among Latinos in the United States, with Puerto Ricans having the highest and Mexicans the lowest.

OBJECTIVE

To determine whether genetic ancestry is associated with the odds of asthma among Latinos, and secondarily whether genetic ancestry is associated with lung function among Latino children.

METHODS

We analyzed 5493 Latinos with and without asthma from 3 independent studies. For each participant, we estimated the proportion of African, European, and Native American ancestry using genome-wide data. We tested whether genetic ancestry was associated with the presence of asthma and lung function among subjects with and without asthma. Odds ratios (OR) and effect sizes were assessed for every 20% increase in each ancestry.

RESULTS

Native American ancestry was associated with lower odds of asthma (OR = 0.72, 95% CI: 0.66-0.78, P = 8.0 × 10(-15)), while African ancestry was associated with higher odds of asthma (OR = 1.40, 95% CI: 1.14-1.72, P = .001). These associations were robust to adjustment for covariates related to early life exposures, air pollution, and socioeconomic status. Among children with asthma, African ancestry was associated with lower lung function, including both pre- and post-bronchodilator measures of FEV1 (-77 ± 19 mL; P = 5.8 × 10(-5) and -83 ± 19 mL; P = 1.1 x 10(-5), respectively) and forced vital capacity (-100 ± 21 mL; P = 2.7 × 10(-6) and -107 ± 22 mL; P = 1.0 x 10(-6), respectively).

CONCLUSION

Differences in the proportions of genetic ancestry can partially explain disparities in asthma susceptibility and lung function among Latinos.

Human genetics. The genetics of Mexico recapitulates Native American substructure and affects biomedical traits

Mexico harbors great cultural and ethnic diversity, yet fine-scale patterns of human genome-wide variation from this region remain largely uncharacterized. We studied genomic variation within Mexico from over 1000 individuals representing 20 indigenous and 11 mestizo populations. We found striking genetic stratification among indigenous populations within Mexico at varying degrees of geographic isolation. Some groups were as differentiated as Europeans are from East Asians. Pre-Columbian genetic substructure is recapitulated in the indigenous ancestry of admixed mestizo individuals across the country. Furthermore, two independently phenotyped cohorts of Mexicans and Mexican Americans showed a significant association between subcontinental ancestry and lung function. Thus, accounting for fine-scale ancestry patterns is critical for medical and population genetic studies within Mexico, in Mexican-descent populations, and likely in many other populations worldwide.

Five National Cancer Institute-designated cancer centers' data collection on racial/ethnic minority participation in therapeutic trials: a current view and opportunities for improvement

BACKGROUND

To ensure that National Institutes of Health-funded research is relevant to the population's needs, specific emphasis on proportional representation of minority/sex groups into National Cancer Institute (NCI) cancer centers' clinical research programs is reported to the NCI.

METHODS

EMPaCT investigators at 5 regionally diverse comprehensive cancer centers compared data reported to the NCI for their most recent Cancer Center Support Grant competitive renewal to assess and compare the centers' catchment area designations, data definitions, data elements, collection processes, reporting, and performance regarding proportional representation of race/ethnicity and sex subsets.

RESULTS

Cancer centers' catchment area definitions differed widely in terms of their cancer patient versus general population specificity, levels of specificity, and geographic coverage. Racial/ethnic categories were similar, yet were defined differently, across institutions. Patients' socioeconomic status and insurance status were inconsistently captured across the 5 centers.

CONCLUSIONS

Catchment area definitions and the collection of patient-level demographic factors varied widely across the 5 comprehensive cancer centers. This challenged the assessment of success by cancer centers in accruing representative populations into the cancer research enterprise. Accrual of minorities was less than desired for at least 1 racial/ethnic subcategory at 4 of the 5 centers. Institutions should clearly and consistently declare their primary catchment area and the rationale and should report how race/ethnicity and sex are defined, determined, collected, and reported. More standardized, frequent, consistent collection, reporting, and review of these data are recommended, as is a commitment to collecting socioeconomic data, given that socioeconomic status is a primary driver of cancer disparities in the United States.

State-of-the-science of patient navigation as a strategy for enhancing minority clinical trial accrual

BACKGROUND

Patient navigation programs are emerging that aim to address disparities in clinical trial participation among medically underserved populations, including racial/ethnic minorities. However, there is a lack of consensus on the role of patient navigators within the clinical trial process as well as outcome measures to evaluate program effectiveness.

METHODS

A review of the literature was conducted of PubMed, Medline, CINHAL, and other sources to identify qualitative and quantitative studies on patient navigation in clinical trials. The search yielded 212 studies, of which only 12 were eligible for this review.

RESULTS

The eligible studies reported on the development of programs for patient navigation in cancer clinical trials, including training and implementation among African Americans, American Indians, and Native Hawaiians. A low rate of clinical trial refusal (range, 4%-6%) was reported among patients enrolled in patient navigation programs. However, few studies reported on the efficacy of patient navigation in increasing clinical treatment trial enrollment.

CONCLUSIONS

Outcome measures are proposed to assist in developing and evaluating the efficacy and/or effectiveness of patient navigation programs that aim to increase participation in cancer clinical trials. Future research is needed to evaluate the efficacy of patient navigators in addressing barriers to clinical trial participation and increasing enrollment among medically underserved cancer patients.

Examination of race disparities in physical inactivity among adults of similar social context

OBJECTIVE

The objective of the study was to determine whether race disparities in physical inactivity are present among urban low-income Blacks and Whites living in similar social context.

DESIGN

This analysis included Black and White respondents ( > or = 18 years) from the Exploring Health Disparities in Integrated Communities-Southwest Baltimore (EHDIC-SWB; N=1350) Study and the National Health Interview Survey (NHIS; N = 67790). Respondents who reported no levels of moderate or vigorous physical activity, during leisure time, over a usual week were considered physically inactive.

RESULTS

After controlling for confounders, Blacks had higher adjusted odds of physical inactivity compared to Whites in the national sample (odds ratio [OR] = 1.40; 95% confidence interval [CI] =1.30-1.51). In EHDIC-SWB, Blacks and Whites had a similar odds of physical inactivity (OR = 1.09; 95% CI .86-1.40).

CONCLUSION

Social context contributes to our understanding of racial disparities in physical inactivity.

The National Cancer Institute-American Society of Clinical Oncology Cancer Trial Accrual Symposium: summary and recommendations

INTRODUCTION

Many challenges to clinical trial accrual exist, resulting in studies with inadequate enrollment and potentially delaying answers to important scientific and clinical questions.

METHODS

The National Cancer Institute (NCI) and the American Society of Clinical Oncology (ASCO) cosponsored the Cancer Trial Accrual Symposium: Science and Solutions on April 29-30, 2010 to examine the state of accrual science related to patient/community, physician/provider, and site/organizational influences, and identify new interventions to facilitate clinical trial enrollment. The symposium featured breakout sessions, plenary sessions, and a poster session including 100 abstracts. Among the 358 attendees were clinical investigators, researchers of accrual strategies, research administrators, nurses, research coordinators, patient advocates, and educators. A bibliography of the accrual literature in these three major areas was provided to participants in advance of the meeting. After the symposium, the literature in these areas was revisited to determine if the symposium recommendations remained relevant within the context of the current literature.

RESULTS

Few rigorously conducted studies have tested interventions to address challenges to clinical trials accrual. Attendees developed recommendations for improving accrual and identified priority areas for future accrual research at the patient/community, physician/provider, and site/organizational levels. Current literature continues to support the symposium recommendations.

CONCLUSIONS

A combination of approaches addressing both the multifactorial nature of accrual challenges and the characteristics of the target population may be needed to improve accrual to cancer clinical trials. Recommendations for best practices and for future research developed from the symposium are provided.

Building a navigation system to reduce cancer disparities among urban Black older adults

BACKGROUND

Although cancer outcomes have improved in recent decades, substantial disparities by race, ethnicity, income, and education persist. Increasingly, patient navigation services are demonstrating success in improving cancer detection, treatment, and care and in reducing cancer health disparities. To advance progress in developing patient navigation programs, extensive descriptions of each component of the program must be made available to researchers and health service providers.

OBJECTIVE

We sought to describe the components of a patient navigation program designed to improve cancer screening based on informed decision making on cancer screening and cancer treatment services among predominantly Black older adults in Baltimore City.

METHODS

A community-academic participatory approach was used to develop a patient navigation program in Baltimore, Maryland. The components of the patient navigation system included the development of a community academic (advisory) committee (CAC); recruitment and selection of community health workers (CHWs)/navigators and supervisory staff, initial training and continuing education of the CHWs/navigators, and evaluation of CHWs/navigators. The study was approved by the Johns Hopkins Bloomberg School of Public Health Institutional Review Board.

CONCLUSIONS

The incorporation of community-based participatory research principles into each facet of this patient navigation program facilitated the attainment of the intervention's objectives. This patient navigation program successfully delivered cancer navigation services to 1,302 urban Black older adults. Appropriately recruited, selected and trained CHWs monitored by an experienced supervisor and investigators are the key elements in a patient navigation program. This model has the potential to be adapted by research and health service providers.

Epidemiology of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Ever since a lung cancer epidemic emerged in the mid-1900 s, the epidemiology of lung cancer has been intensively investigated to characterize its causes and patterns of occurrence. This report summarizes the key findings of this research.

METHODS

A detailed literature search provided the basis for a narrative review, identifying and summarizing key reports on population patterns and factors that affect lung cancer risk.

RESULTS

Established environmental risk factors for lung cancer include smoking cigarettes and other tobacco products and exposure to secondhand tobacco smoke, occupational lung carcinogens, radiation, and indoor and outdoor air pollution. Cigarette smoking is the predominant cause of lung cancer and the leading worldwide cause of cancer death. Smoking prevalence in developing nations has increased, starting new lung cancer epidemics in these nations. A positive family history and acquired lung disease are examples of host factors that are clinically useful risk indicators. Risk prediction models based on lung cancer risk factors have been developed, but further refinement is needed to provide clinically useful risk stratification. Promising biomarkers of lung cancer risk and early detection have been identified, but none are ready for broad clinical application.

CONCLUSIONS

Almost all lung cancer deaths are caused by cigarette smoking, underscoring the need for ongoing efforts at tobacco control throughout the world. Further research is needed into the reasons underlying lung cancer disparities, the causes of lung cancer in never smokers, the potential role of HIV in lung carcinogenesis, and the development of biomarkers.

Gender differences in correlates of colorectal cancer screening among Black Medicare beneficiaries in Baltimore

BACKGROUND

Previous research has shown colorectal cancer (CRC) screening disparities by gender. Little research has focused primarily on gender differences among older Black individuals, and reasons for existing gender differences remain poorly understood.

METHODS

We used baseline data from the Cancer Prevention and Treatment Demonstration Screening Trial. Participants were recruited from November 2006 to March 2010. In-person interviews were used to assess self-reported CRC screening behavior. Up-to-date CRC screening was defined as self-reported colonoscopy or sigmoidoscopy in the past 10 years or fecal occult blood testing in the past year. We used multivariable logistic regression to examine the association between gender and self-reported screening, adjusting for covariates. The final model was stratified by gender to examine factors differentially associated with screening outcomes for males and females.

RESULTS

The final sample consisted of 1,552 female and 586 male Black Medicare beneficiaries in Baltimore, Maryland. Males were significantly less likely than females to report being up-to-date with screening (77.5% vs. 81.6%, P = 0.030), and this difference was significant in the fully adjusted model (OR: 0.72; 95% confidence interval, 0.52-0.99). The association between having a usual source of care and receipt of cancer screening was stronger among males compared with females.

CONCLUSIONS

Although observed differences in CRC screening were small, several factors suggest that gender-specific approaches may be used to promote screening adherence among Black Medicare beneficiaries.

IMPACT

Given disproportionate CRC mortality between White and Black Medicare beneficiaries, gender-specific interventions aimed at increasing CRC screening may be warranted among older Black patients.

Analysis of Latino populations from GALA and MEC studies reveals genomic loci with biased local ancestry estimation

MOTIVATION

Local ancestry analysis of genotype data from recently admixed populations (e.g. Latinos, African Americans) provides key insights into population history and disease genetics. Although methods for local ancestry inference have been extensively validated in simulations (under many unrealistic assumptions), no empirical study of local ancestry accuracy in Latinos exists to date. Hence, interpreting findings that rely on local ancestry in Latinos is challenging.

RESULTS

Here, we use 489 nuclear families from the mainland USA, Puerto Rico and Mexico in conjunction with 3204 unrelated Latinos from the Multiethnic Cohort study to provide the first empirical characterization of local ancestry inference accuracy in Latinos. Our approach for identifying errors does not rely on simulations but on the observation that local ancestry in families follows Mendelian inheritance. We measure the rate of local ancestry assignments that lead to Mendelian inconsistencies in local ancestry in trios (MILANC), which provides a lower bound on errors in the local ancestry estimates. We show that MILANC rates observed in simulations underestimate the rate observed in real data, and that MILANC varies substantially across the genome. Second, across a wide range of methods, we observe that loci with large deviations in local ancestry also show enrichment in MILANC rates. Therefore, local ancestry estimates at such loci should be interpreted with caution. Finally, we reconstruct ancestral haplotype panels to be used as reference panels in local ancestry inference and show that ancestry inference is significantly improved by incoroprating these reference panels.

AVAILABILITY AND IMPLEMENTATION

We provide the reconstructed reference panels together with the maps of MILANC rates as a public resource for researchers analyzing local ancestry in Latinos at http://bogdanlab.pathology.ucla.edu

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Contribution of higher risk genes and European admixture to Crohn's disease in African Americans

BACKGROUND

African Americans (AAs) are an admixed population of West African (WA) and European ancestry (EA). Crohn's disease (CD) susceptibility genes have not been established. We therefore evaluated the contribution of European admixture and major established risk genes to AA CD.

METHODS

Ninety-seven admixture informative markers were genotyped for ancestry estimates using STRUCTURE. Overall, 354 AA CD cases and 354 ethnicity-matched controls were genotyped for total 21 single nucleotide polymorphisms (SNPs) in ATG16L1, NOD2, IBD5, IL23R and IRGM by TaqMan or direct sequencing. Association was evaluated by logistic regression, adjusted for ancestry.

RESULTS

Mean EA was similar among the CD cases and controls (20.9% and 20.4%, respectively, P = 0.58). No significant admixture differences were observed among 211 to 227 cases stratified by phenotypic subclassifications including onset, surgery, site, and behavior. CD was associated with NOD2 carrier (6.93% CD, 2.15% Controls, P = 0.007), ATG16L1 Thr300Ala (36.1% CD, 29.3% Controls, P = 0.003), SLC22A4 and SLC22A5 (IBD5 locus) functional SNPs (Leu503Phe [10.5% CD, 7.6% Controls, P = 0.05] and g-207c [41.3% CD, 35.7% Controls, P = 0.03], respectively), and IL23R rs2201841 (18.2% CD, 13.8% Controls, P = 0.03), but not IRGM variants, nor three African ancestral NOD2 nonsynonymous variants. IBD5 risk was recessive. An all-minor allele IBD5 haplotype from EA was associated (P = 0.05), whereas a more common haplotype isolating g-207c was not.

CONCLUSIONS

Specific functional gene variations contribute significantly to AA CD risk. Established NOD2, SLC22A4-A5, and ATG16L1 variants show increased CD risk, with IBD5 recessive. Although CD is more common in whites, European admixture is similar among AA cases and controls.

Cancer support and resource needs among African American older adults

Older African Americans face substantial barriers to state-of-the-art cancer care. Implementing culturally appropriate support throughout cancer therapy is critical to improving cancer outcomes and quality of life for this vulnerable population. The purpose of this study was to obtain experiential data regarding cancer diagnosis and treatment, and analyze survivors' recommendations regarding treatment-related needs, psychosocial support, and strategies and resources. Four main issues emerged from the study: (a) the need for more health-related and cancer-specific education, (b) the importance of faith and spirituality, (c) the availability of support, and (d) participants' difficulty identifying and articulating financial needs. Few participants reported requesting or receiving assistance (financial or otherwise) outside of the family during their cancer experience. However, treatment-related medication costs posed a significant hardship for many.

Genome-wide ancestry association testing identifies a common European variant on 6q14.1 as a risk factor for asthma in African American subjects

BACKGROUND

Genetic variants that contribute to asthma susceptibility might be present at varying frequencies in different populations, which is an important consideration and advantage for performing genetic association studies in admixed populations.

OBJECTIVE

We sought to identify asthma-associated loci in African American subjects.

METHODS

We compared local African and European ancestry estimated from dense single nucleotide polymorphism genotype data in African American adults with asthma and nonasthmatic control subjects. Allelic tests of association were performed within the candidate regions identified, correcting for local European admixture.

RESULTS

We identified a significant ancestry association peak on chromosome 6q. Allelic tests for association within this region identified a single nucleotide polymorphism (rs1361549) on 6q14.1 that was associated with asthma exclusively in African American subjects with local European admixture (odds ratio, 2.2). The risk allele is common in Europe (42% in the HapMap population of Utah residents with Northern and Western European ancestry from the Centre d'Etude du Polymorphisme Humain collection) but absent in West Africa (0% in the HapMap population of Yorubans in Ibadan, Nigeria), suggesting the allele is present in African American subjects because of recent European admixture. We replicated our findings in Puerto Rican subjects and similarly found that the signal of association is largely specific to subjects who are heterozygous for African and non-African ancestry at 6q14.1. However, we found no evidence for association in European American or Puerto Rican subjects in the absence of local African ancestry, suggesting that the association with asthma at rs1361549 is due to an environmental or genetic interaction.

CONCLUSION

We identified a novel asthma-associated locus that is relevant to admixed populations with African ancestry and highlight the importance of considering local ancestry in genetic association studies of admixed populations.

Fast and accurate inference of local ancestry in Latino populations

MOTIVATION

It is becoming increasingly evident that the analysis of genotype data from recently admixed populations is providing important insights into medical genetics and population history. Such analyses have been used to identify novel disease loci, to understand recombination rate variation and to detect recent selection events. The utility of such studies crucially depends on accurate and unbiased estimation of the ancestry at every genomic locus in recently admixed populations. Although various methods have been proposed and shown to be extremely accurate in two-way admixtures (e.g. African Americans), only a few approaches have been proposed and thoroughly benchmarked on multi-way admixtures (e.g. Latino populations of the Americas).

RESULTS

To address these challenges we introduce here methods for local ancestry inference which leverage the structure of linkage disequilibrium in the ancestral population (LAMP-LD), and incorporate the constraint of Mendelian segregation when inferring local ancestry in nuclear family trios (LAMP-HAP). Our algorithms uniquely combine hidden Markov models (HMMs) of haplotype diversity within a novel window-based framework to achieve superior accuracy as compared with published methods. Further, unlike previous methods, the structure of our HMM does not depend on the number of reference haplotypes but on a fixed constant, and it is thereby capable of utilizing large datasets while remaining highly efficient and robust to over-fitting. Through simulations and analysis of real data from 489 nuclear trio families from the mainland US, Puerto Rico and Mexico, we demonstrate that our methods achieve superior accuracy compared with published methods for local ancestry inference in Latinos.

Case-control admixture mapping in Latino populations enriches for known asthma-associated genes

BACKGROUND

Polymorphisms in more than 100 genes have been associated with asthma susceptibility, yet much of the heritability remains to be explained. Asthma disproportionately affects different racial and ethnic groups in the United States, suggesting that admixture mapping is a useful strategy to identify novel asthma-associated loci.

OBJECTIVE

We sought to identify novel asthma-associated loci in Latino populations using case-control admixture mapping.

METHODS

We performed genome-wide admixture mapping by comparing levels of local Native American, European, and African ancestry between children with asthma and nonasthmatic control subjects in Puerto Rican and Mexican populations. Within candidate peaks, we performed allelic tests of association, controlling for differences in local ancestry.

RESULTS

Between the 2 populations, we identified a total of 62 admixture mapping peaks at a P value of less than 10(-3) that were significantly enriched for previously identified asthma-associated genes (P= .0051). One of the peaks was statistically significant based on 100 permutations in the Mexican sample (6q15); however, it was not significant in Puerto Rican subjects. Another peak was identified at nominal significance in both populations (8q12); however, the association was observed with different ancestries.

CONCLUSION

Case-control admixture mapping is a promising strategy for identifying novel asthma-associated loci in Latino populations and implicates genetic variation at 6q15 and 8q12 regions with asthma susceptibility. This approach might be useful for identifying regions that contribute to both shared and population-specific differences in asthma susceptibility.

Development of a panel of genome-wide ancestry informative markers to study admixture throughout the Americas

Most individuals throughout the Americas are admixed descendants of Native American, European, and African ancestors. Complex historical factors have resulted in varying proportions of ancestral contributions between individuals within and among ethnic groups. We developed a panel of 446 ancestry informative markers (AIMs) optimized to estimate ancestral proportions in individuals and populations throughout Latin America. We used genome-wide data from 953 individuals from diverse African, European, and Native American populations to select AIMs optimized for each of the three main continental populations that form the basis of modern Latin American populations. We selected markers on the basis of locus-specific branch length to be informative, well distributed throughout the genome, capable of being genotyped on widely available commercial platforms, and applicable throughout the Americas by minimizing within-continent heterogeneity. We then validated the panel in samples from four admixed populations by comparing ancestry estimates based on the AIMs panel to estimates based on genome-wide association study (GWAS) data. The panel provided balanced discriminatory power among the three ancestral populations and accurate estimates of individual ancestry proportions (R²>0.9 for ancestral components with significant between-subject variance). Finally, we genotyped samples from 18 populations from Latin America using the AIMs panel and estimated variability in ancestry within and between these populations. This panel and its reference genotype information will be useful resources to explore population history of admixture in Latin America and to correct for the potential effects of population stratification in admixed samples in the region.

Individuals from Latin America are descendants of multiple ancestral populations, primarily Native American, European, and African ancestors. The relative proportions of these ancestries can be estimated using genetic markers, known as ancestry informative markers (AIMs), whose allele frequency varies between the ancestral groups. Once determined, these ancestral proportions can be correlated with normal phenotypes, can be associated with disease, can be used to control for confounding due to population stratification, or can inform on the history of admixture in a population. In this study, we identified a panel of AIMs relevant to Latin American populations, validated the panel by comparing estimates of ancestry using the panel to ancestry determined from genome-wide data, and tested the panel in a diverse set of populations from the Americas. The panel of AIMs produces ancestry estimates that are highly accurate and appropriately controlled for population stratification, and it was used to genotype 18 populations from throughout Latin America. We have made the panel of AIMs available to any researcher interested in estimating ancestral proportions for populations from the Americas.

Abstract B23: Socioeconomic factors and correlates of prostatespecific antigen testing in urban African-American Medicare beneficiaries

Background: Prostate specific antigen (PSA) testing is frequently used for early detection of prostate cancer, including among older adults. Since both race and socioeconomic status are associated with prostate cancer incidence and outcomes, it is often difficult to separate race from socioeconomic status as a determinant of prostate cancer screening. We sought to describe the relationship between socioeconomic status and PSA testing in a sample of urban, African American Medicare beneficiaries, and to examine factors that may contribute to this relationship.

Methods: We examined baseline questionnaire data collected from the Cancer Prevention and Treatment Demonstration, a community-based randomized, controlled trial in Baltimore, MD. The study population consisted of 511 community-dwelling African-American men, age 65–75, without a history of prostate cancer. Our main outcome was PSA testing within the past year. Sequential multivariate logistic regression models were performed to study factors that may mediate the relationship between socioeconomic status and PSA screening.

Results: Eighty percent of participants reported having had at least one PSA test in their lifetime, and approximately 50% reported having one within the past year. About half of the sample population reported a household income of less than $30,000 a year and one-third reported education past high school, but only 14% reported a bachelor's degree or higher. In bivariate analyses both higher income ($30,000 vs. &lt; $10,000) (Odds Ratio [OR] 3.14, 95% Confidence Interval [CI] 1.79, 5.52) and higher levels of education (Bachelor's degree vs. less than high school) (OR 3.19, CI 1.72, 5.71) were associated with screening in the past year. In a multivariable regression model, which controlled for marital status, family history, and self-reported health status, income was no longer a significantly associated with PSA testing while the association between educational attainment and PSA testing was reduced (OR 2.13, 95% CI 1.07–4.22). The addition of increased healthcare access and patient-provider relationship measures in sequential models did not alter the relationship between educational attainment and screening. However, upon inclusion of cancer knowledge and belief measures the association between education and PSA testing was no longer significant (OR 1.84, 95% CI 0.90–3.75).

Conclusions: In this urban, African American Medicare population, socioeconomic status was associated with PSA testing. This relationship may be explained, in part, by demographic factors and cancer knowledge and beliefs.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B23.

Abstract B11: Effect of patient navigation on colorectal cancer screening in a community-based randomized controlled trial of urban African American Medicare beneficiaries

Background: In recent years, colorectal cancer screening rates have increased steadily in the United States, though racial and ethnic disparities persist. We investigated the effect of a patient navigation intervention on adherence to colorectal cancer screening guidelines among African American older adults in Baltimore, MD.

Methods: We examined data collected from the Cancer Prevention and Treatment Demonstration (CPTD), a community-based randomized, controlled trial. Our study population consisted of 661 African American men and women aged 65 to 75 years who were Medicare beneficiaries and residents of Baltimore City. Participants were randomized to receive either printed educational materials only (PEM) or the addition of a patient navigator (NAV). The Johns Hopkins trained and certified patient navigator assisted participants with identifying and overcoming potential barriers to cancer screening. Self-reported colorectal cancer screening data were collected at baseline and at one-year follow-up through inperson interviews. Rates of screening between the two groups were examined using multivariable logistic regression modeling. All participants irrespective of their baseline screening status were included in calculating the adjusted odds of completing colorectal cancer screening during the follow-up period.

Results: At baseline, 68% of the PEM group and 71% of the NAV group (P = 0.45) reported being up-to-date with colorectal cancer screening, defined as having either a fecal occult blood test (FOBT) within one year or colonoscopy/sigmoidoscopy within ten years of randomization. At the one-year follow-up visit, participants in the NAV group were more likely to report having undergone any colorectal cancer screening during the previous year, compared to the PEM group, 54% versus 46%, though this did not reach statistical significance (P = 0.12). After adjusting for age, gender, number of co-morbidities, education, participants’ health perception and level of health literacy, individuals in the NAV group were more likely to report being screened by colonoscopy/sigmoidoscopy (OR, 1.53; 95% CI, 1.07–2.18) compared to those in the PEM group. Individuals who underwent patient navigation did not have a statistically significant change in the likelihood of reporting a FOBT compared to the PEM group.

Conclusions: In a population of urban African American older adults, patient navigation was effective in increasing the likelihood of screening by colonoscopy/sigmoidoscopy but not fecal occult blood testing at one-year follow-up. The lack of effect on screening by FOBT likely represents the relatively low rate of provider utilization of this screening modality in the target population.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B11.