Minority recruitment to the Selenium and Vitamin E Cancer Prevention Trial (SELECT)

Accommodating population differences when validating risk prediction models

Validation of risk prediction models in independent data provides a more rigorous assessment of model performance than internal assessment, for example, done by cross-validation in the data used for model development. However, several differences between the populations that gave rise to the training and the validation data can lead to seemingly poor performance of a risk model. In this paper we formalize the notions of "similarity" or "relatedness" of the training and validation data, and define reproducibility and transportability. We address the impact of different distributions of model predictors and differences in verifying the disease status or outcome on measures of calibration, accuracy and discrimination of a model. When individual level information from both the training and validation data sets is available, we propose and study weighted versions of the validation metrics that adjust for differences in the risk factor distributions and in outcome verification between the training and validation data to provide a more comprehensive assessment of model performance. We provide conditions on the risk model and the populations that gave rise to the training and validation data that ensure a model's reproducibility or transportability, and show how to check these conditions using weighted and unweighted performance measures. We illustrate the method by developing and validating a model that predicts the risk of developing prostate cancer using data from two large prostate cancer screening trials.

Willingness to participate in various nontherapeutic cancer research activities among urban and rural African American and Latinx healthy volunteers

PURPOSE

Inclusion of racial/ethnic minorities in cancer research can reduce disparities in health outcomes; however, data regarding barriers and motivators to participation are sparse. This study assessed African American (AA) and Latinx healthy volunteers' perspectives regarding willingness to participate in noninvasive and invasive research activities.

METHODS

Using a 38-item questionnaire adapted from the Tuskegee Legacy Project Questionnaire, we assessed willingness to participate in 12 research activities, offering 27 possible barriers and 14 motivators. The sample was segmented into four subgroups by AA/Latinx and rural/urban.

RESULTS

Across five states and Puerto Rico, 533 participants completed questionnaires. Overall, participants were more willing to participate in noninvasive versus invasive procedures, although, all subgroups were willing to participate in research if asked. Rural AA were most willing to complete a survey or saliva sample, while rural Latinx were least willing. Urban AA were least willing to provide cheek swab, while rural counterparts were most willing. Self-benefit and benefit to others were among the top three motivators for all subgroups. Curiosity was a primary motivator for urban AA while obtaining health information motivated rural Latinx. Primary barriers included fears of side effects and being experimented on, lack of information, and lack of confidentiality.

CONCLUSIONS

Latinx and AAs are willing to participate in the continuum of nontherapeutic research activities suggesting their lack of participation may be related to not being asked. Inclusive enrollment may be achieved by assessing needs of participants during the design phase of a study in order to reduce barriers to participation.

Willingness of Latinx and African Americans to Participate in Nontherapeutic Trials: It Depends on Who Runs the Research

Background

Inclusion of racial/ethnic minorities in cancer-related research remains inadequate, continuing to impact disparate health outcomes. Data regarding enrollment of racial/ethnic minorities in nontherapeutic, health-related research is sparse, and even less is known about enrollment of those with a double disparity of racial/ethnic minorities in rural settings.

Objective

To examine perspectives of Latinx and African American (AA) healthy volunteers from rural and urban settings in five southern US states and Puerto Rico regarding their trust in research and their willingness to participate in nontherapeutic research trials based on who conducts the research.

Methods

This study was conducted in 2013 in rural and urban communities across Alabama, Florida, Georgia, Mississippi, Louisiana, and Puerto Rico. A 38-item questionnaire based on the Tuskegee Legacy Project Questionnaire assessed willingness, motivators, and barriers to participation in nontherapeutic cancer-related research. The sample was segmented into four subgroups by urban/rural location and race/ethnicity.

Results

Of 553 participants (rural Latinx=151, urban Latinx=158, rural AA=122, urban AA=122), more than 90% had never been asked to participate in research, yet 75% of those asked agreed to participate. Most had positive views regarding health-related research. Trust in who conducted research varied by subgroup. Personal doctors and university hospitals were most trusted by all subgroups; for-profit and tobacco companies were least trusted. Both Latinx subgroups trusted pharmaceutical companies more than AAs; local hospitals and for-profit businesses were more trusted by AAs. Both rural subgroups trusted research by insurance companies more than their urban counterparts.

Conclusions

If asked, rural and urban AA and Latinx healthy volunteers were willing to participate in health-related research, with personal doctors and university hospitals considered the most trusted sources to encourage/conduct research.

Selenium for preventing cancer

BACKGROUND

This review is the third update of the Cochrane review "Selenium for preventing cancer". Selenium is a naturally occurring element with both nutritional and toxicological properties. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancer.

OBJECTIVES

To gather and present evidence needed to address two research questions:1. What is the aetiological relationship between selenium exposure and cancer risk in humans?2. Describe the efficacy of selenium supplementation for cancer prevention in humans.

SEARCH METHODS

We updated electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), MEDLINE (Ovid, 2013 to January 2017, week 4), and Embase (2013 to 2017, week 6), as well as searches of clinical trial registries.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and longitudinal observational studies that enrolled adult participants.

DATA COLLECTION AND ANALYSIS

We performed random-effects (RE) meta-analyses when two or more RCTs were available for a specific outcome. We conducted RE meta-analyses when five or more observational studies were available for a specific outcome. We assessed risk of bias in RCTs and in observational studies using Cochrane's risk assessment tool and the Newcastle-Ottawa Scale, respectively. We considered in the primary analysis data pooled from RCTs with low risk of bias. We assessed the certainty of evidence by using the GRADE approach.

MAIN RESULTS

We included 83 studies in this updated review: two additional RCTs (10 in total) and a few additional trial reports for previously included studies. RCTs involved 27,232 participants allocated to either selenium supplements or placebo. For analyses of RCTs with low risk of bias, the summary risk ratio (RR) for any cancer incidence was 1.01 (95% confidence interval (CI) 0.93 to 1.10; 3 studies, 19,475 participants; high-certainty evidence). The RR for estimated cancer mortality was 1.02 (95% CI 0.80 to 1.30; 1 study, 17,444 participants). For the most frequently investigated site-specific cancers, investigators provided little evidence of any effect of selenium supplementation. Two RCTs with 19,009 participants indicated that colorectal cancer was unaffected by selenium administration (RR 0.99, 95% CI 0.69 to 1.43), as were non-melanoma skin cancer (RR 1.16, 95% CI 0.30 to 4.42; 2 studies, 2027 participants), lung cancer (RR 1.16, 95% CI 0.89 to 1.50; 2 studies, 19,009 participants), breast cancer (RR 2.04, 95% CI 0.44 to 9.55; 1 study, 802 participants), bladder cancer (RR 1.07, 95% CI 0.76 to 1.52; 2 studies, 19,009 participants), and prostate cancer (RR 1.01, 95% CI 0.90 to 1.14; 4 studies, 18,942 participants). Certainty of the evidence was high for all of these cancer sites, except for breast cancer, which was of moderate certainty owing to imprecision, and non-melanoma skin cancer, which we judged as moderate certainty owing to high heterogeneity. RCTs with low risk of bias suggested increased melanoma risk.Results for most outcomes were similar when we included all RCTs in the meta-analysis, regardless of risk of bias. Selenium supplementation did not reduce overall cancer incidence (RR 0.99, 95% CI 0.86 to 1.14; 5 studies, 21,860 participants) nor mortality (RR 0.81, 95% CI 0.49 to 1.32; 2 studies, 18,698 participants). Summary RRs for site-specific cancers showed limited changes compared with estimates from high-quality studies alone, except for liver cancer, for which results were reversed.In the largest trial, the Selenium and Vitamin E Cancer Trial, selenium supplementation increased risks of alopecia and dermatitis, and for participants with highest background selenium status, supplementation also increased risk of high-grade prostate cancer. RCTs showed a slightly increased risk of type 2 diabetes associated with supplementation. A hypothesis generated by the Nutritional Prevention of Cancer Trial - that individuals with low blood selenium levels could reduce their risk of cancer (particularly prostate cancer) by increasing selenium intake - has not been confirmed. As RCT participants have been overwhelmingly male (88%), we could not assess the potential influence of sex or gender.We included 15 additional observational cohort studies (70 in total; over 2,360,000 participants). We found that lower cancer incidence (summary odds ratio (OR) 0.72, 95% CI 0.55 to 0.93; 7 studies, 76,239 participants) and lower cancer mortality (OR 0.76, 95% CI 0.59 to 0.97; 7 studies, 183,863 participants) were associated with the highest category of selenium exposure compared with the lowest. Cancer incidence was lower in men (OR 0.72, 95% CI 0.46 to 1.14, 4 studies, 29,365 men) than in women (OR 0.90, 95% CI 0.45 to 1.77, 2 studies, 18,244 women). Data show a decrease in risk of site-specific cancers for stomach, colorectal, lung, breast, bladder, and prostate cancers. However, these studies have major weaknesses due to study design, exposure misclassification, and potential unmeasured confounding due to lifestyle or nutritional factors covarying with selenium exposure beyond those taken into account in multi-variable analyses. In addition, no evidence of a dose-response relation between selenium status and cancer risk emerged. Certainty of evidence was very low for each outcome. Some studies suggested that genetic factors might modify the relation between selenium and cancer risk - an issue that merits further investigation.

AUTHORS' CONCLUSIONS

Well-designed and well-conducted RCTs have shown no beneficial effect of selenium supplements in reducing cancer risk (high certainty of evidence). Some RCTs have raised concerns by reporting a higher incidence of high-grade prostate cancer and type 2 diabetes in participants with selenium supplementation. No clear evidence of an influence of baseline participant selenium status on outcomes has emerged in these studies.Observational longitudinal studies have shown an inverse association between selenium exposure and risk of some cancer types, but null and direct relations have also been reported, and no systematic pattern suggesting dose-response relations has emerged. These studies suffer from limitations inherent to the observational design, including exposure misclassification and unmeasured confounding.Overall, there is no evidence to suggest that increasing selenium intake through diet or supplementation prevents cancer in humans. However, more research is needed to assess whether selenium may modify the risk of cancer in individuals with a specific genetic background or nutritional status, and to investigate possible differential effects of various forms of selenium.

The Role of Clinical Trial Participation in Cancer Research: Barriers, Evidence, and Strategies

Fewer than one in 20 adult patients with cancer enroll in cancer clinical trials. Although barriers to trial participation have been the subject of frequent study, the rate of trial participation has not changed substantially over time. Barriers to trial participation are structural, clinical, and attitudinal, and they differ according to demographic and socioeconomic factors. In this article, we characterize the nature of cancer clinical trial barriers, and we consider global and local strategies for reducing barriers. We also consider the specific case of adolescents with cancer and show that the low rate of trial enrollment in this age group strongly correlates with limited improvements in cancer population outcomes compared with other age groups. Our analysis suggests that a clinical trial system that enrolls patients at a higher rate produces treatment advances at a faster rate and corresponding improvements in cancer population outcomes. Viewed in this light, the issue of clinical trial enrollment is foundational, lying at the heart of the cancer clinical trial endeavor. Fewer barriers to trial participation would enable trials to be completed more quickly and would improve the generalizability of trial results. Moreover, increased accrual to trials is important for patients, because trials provide patients the opportunity to receive the newest treatments. In an era of increasing emphasis on a treatment decision-making process that incorporates the patient perspective, the opportunity for patients to choose trial participation for their care is vital.

Applying a Conceptual Framework to Maximize the Participation of Diverse Populations in Cancer Clinical Trials

The underrepresentation of ethnically diverse populations in cancer clinical trials results in the inequitable distribution of the risks and benefits of this research. Using a case study approach, we apply a conceptual framework of factors associated with the participation of diverse population groups in cancer clinical trials developed by Dr. Jean Ford and colleagues to increase understanding of the specific strategies, and barriers and promoters addressed by these strategies, that resulted in marked success in accrual of racially and ethnically diverse populations in cancer clinical research. Results indicate that the studies presented were able to successfully engage minority participants due to the creation and implementation of multilevel, multifaceted strategies that included: culturally and linguistically appropriate outreach, education, and research studies that were accessible in local communities; infrastructure to support engagement of key stakeholders, clinicians, and organizations serving minority communities; testimonials by ethnically diverse cancer survivors; availability of medical interpretation services; and providing infrastructure that facilitated the engagement in clinical research of clinicians who care for minority patient populations. These strategic efforts were effective in addressing limited awareness of trials, lack of opportunities to participate, and acceptance of engagement in cancer clinical trials. Careful attention to the context and population characteristics in which cancer clinical trials are conducted will be necessary to address disparities in research participation and cancer outcomes. These studies illustrate that progress on minority accrual into clinical research requires intentional efforts to overcome barriers at all three stages of the accrual process: awareness, opportunity, and acceptance of participation.

The Role of Clinical Trial Participation in Cancer Research: Barriers, Evidence, and Strategies

Fewer than one in 20 adult patients with cancer enroll in cancer clinical trials. Although barriers to trial participation have been the subject of frequent study, the rate of trial participation has not changed substantially over time. Barriers to trial participation are structural, clinical, and attitudinal, and they differ according to demographic and socioeconomic factors. In this article, we characterize the nature of cancer clinical trial barriers, and we consider global and local strategies for reducing barriers. We also consider the specific case of adolescents with cancer and show that the low rate of trial enrollment in this age group strongly correlates with limited improvements in cancer population outcomes compared with other age groups. Our analysis suggests that a clinical trial system that enrolls patients at a higher rate produces treatment advances at a faster rate and corresponding improvements in cancer population outcomes. Viewed in this light, the issue of clinical trial enrollment is foundational, lying at the heart of the cancer clinical trial endeavor. Fewer barriers to trial participation would enable trials to be completed more quickly and would improve the generalizability of trial results. Moreover, increased accrual to trials is important for patients, because trials provide patients the opportunity to receive the newest treatments. In an era of increasing emphasis on a treatment decision-making process that incorporates the patient perspective, the opportunity for patients to choose trial participation for their care is vital.

African American Participation in Oncology Clinical Trials--Focus on Prostate Cancer: Implications, Barriers, and Potential Solutions

In the United States, the incidence and mortality rates of many cancers, especially prostate cancer, are disproportionately high among African American men compared with Caucasian men. Recently, mortality rates for prostate cancer have declined more rapidly in African American versus Caucasian men, but prostate cancer is still the most common cancer and the second leading cause of cancer deaths in African American men in the United States. Compared with Caucasian men, prostate cancer occurs at younger ages, has a higher stage at diagnosis, and is more likely to progress after definitive treatments in African American men. Reasons for racial discrepancies in cancer are multifactorial and potentially include socioeconomic, cultural, nutritional, and biologic elements. In addition to improving access to novel therapies, clinical trial participation is essential to adequately establish the risks and benefits of treatments in African American populations. Considering the disproportionately high mortality rates noted in these groups, our understanding of the natural history and responses to therapies is limited. This review will explore African American underrepresentation in clinical trials with a focus on prostate cancer, and potentially effective strategies to engage African American communities in prostate cancer research. Solutions targeting physicians, investigators, the community, and health care systems are identified. Improvement of African American participation in prostate cancer clinical trials will benefit all stakeholders.

Retention of black and white participants in the selenium and vitamin E cancer prevention trial (SWOG-coordinated intergroup study S0000)

BACKGROUND

Disproportionally low retention of minority populations can adversely affect the generalizability of clinical research trials. We determine the overall retention rates for White and Black participants from the Selenium and Vitamin E Cancer Prevention Trial (SELECT) and explore participant and site characteristics associated with retention failure (study disengagement) for these groups.

METHODS

A secondary analysis of 28,118 White (age ≥55), and 4,322 Black (age ≥ 50) SELECT participants used multivariate Cox regression to estimate overall retention rates and to calculate HRs and 95% confidence intervals (CI).

RESULTS

Blacks had higher age-adjusted risk of disengagement than Whites (HR, 1.92; 95% CI, 1.77-2.08). Among Black participants, those ages 50 to 54 were at three times the risk of disengagement than those ≥65 years of age (HR, 3.61; 95% CI, 2.41-5.41). Blacks age ≥65 had 1.6 times the risk of disengagement than Whites age ≥65 (HR, 1.60; 95% CI, 1.38-1.87). By 6 years after randomization, 84% of Whites and 69% of Blacks remained engaged in the study. Current smoking status was an independent risk factor for study disengagement for both White and Black participants. For both groups, sites whose staffs missed SELECT training sessions or who received SELECT Retention and Adherence grants were associated with increased and decreased disengagement risks, respectively.

CONCLUSIONS

SELECT retention was disproportionately lower for Blacks than for Whites.

IMPACT

The observed difference in retention rates for Blacks and Whites and factors identified by race for study disengagement in SELECT may inform retention efforts for future long-term, cancer prevention trials.

Selenium for preventing cancer

BACKGROUND

This review is an update of the first Cochrane publication on selenium for preventing cancer (Dennert 2011).Selenium is a metalloid with both nutritional and toxicological properties. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancers.

OBJECTIVES

Two research questions were addressed in this review: What is the evidence for:1. an aetiological relation between selenium exposure and cancer risk in humans? and2. the efficacy of selenium supplementation for cancer prevention in humans?

SEARCH METHODS

We conducted electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL, 2013, Issue 1), MEDLINE (Ovid, 1966 to February 2013 week 1), EMBASE (1980 to 2013 week 6), CancerLit (February 2004) and CCMed (February 2011). As MEDLINE now includes the journals indexed in CancerLit, no further searches were conducted in this database after 2004.

SELECTION CRITERIA

We included prospective observational studies (cohort studies including sub-cohort controlled studies and nested case-control studies) and randomised controlled trials (RCTs) with healthy adult participants (18 years of age and older).

DATA COLLECTION AND ANALYSIS

For observational studies, we conducted random effects meta-analyses when five or more studies were retrieved for a specific outcome. For RCTs, we performed random effects meta-analyses when two or more studies were available. The risk of bias in observational studies was assessed using forms adapted from the Newcastle-Ottawa Quality Assessment Scale for cohort and case-control studies; the criteria specified in the Cochrane Handbook for Systematic Reviews of Interventions were used to evaluate the risk of bias in RCTs.

MAIN RESULTS

We included 55 prospective observational studies (including more than 1,100,000 participants) and eight RCTs (with a total of 44,743 participants). For the observational studies, we found lower cancer incidence (summary odds ratio (OR) 0.69, 95% confidence interval (CI) 0.53 to 0.91, N = 8) and cancer mortality (OR 0.60, 95% CI 0.39 to 0.93, N = 6) associated with higher selenium exposure. Gender-specific subgroup analysis provided no clear evidence of different effects in men and women (P value 0.47), although cancer incidence was lower in men (OR 0.66, 95% CI 0.42 to 1.05, N = 6) than in women (OR 0.90, 95% CI 0.45 to 1.77, N = 2). The most pronounced decreases in risk of site-specific cancers were seen for stomach, bladder and prostate cancers. However, these findings have limitations due to study design, quality and heterogeneity that complicate interpretation of the summary statistics. Some studies suggested that genetic factors may modify the relation between selenium and cancer risk-a hypothesis that deserves further investigation.In RCTs, we found no clear evidence that selenium supplementation reduced the risk of any cancer (risk ratio (RR) 0.90, 95% CI 0.70 to 1.17, two studies, N = 4765) or cancer-related mortality (RR 0.81, 95% CI 0.49 to 1.32, two studies, N = 18,698), and this finding was confirmed when the analysis was restricted to studies with low risk of bias. The effect on prostate cancer was imprecise (RR 0.90, 95% CI 0.71 to 1.14, four studies, N = 19,110), and when the analysis was limited to trials with low risk of bias, the interventions showed no effect (RR 1.02, 95% CI 0.90 to 1.14, three studies, N = 18,183). The risk of non-melanoma skin cancer was increased (RR 1.44, 95% CI 0.95 to 1.17, three studies, N = 1900). Results of two trials-the Nutritional Prevention of Cancer Trial (NPCT) and the Selenium and Vitamin E Cancer Trial (SELECT)-also raised concerns about possible increased risk of type 2 diabetes, alopecia and dermatitis due to selenium supplements. An early hypothesis generated by NPCT that individuals with the lowest blood selenium levels at baseline could reduce their risk of cancer, particularly of prostate cancer, by increasing selenium intake has not been confirmed by subsequent trials. As the RCT participants were overwhelmingly male (94%), gender differences could not be systematically assessed.

AUTHORS' CONCLUSIONS

Although an inverse association between selenium exposure and the risk of some types of cancer was found in some observational studies, this cannot be taken as evidence of a causal relation, and these results should be interpreted with caution. These studies have many limitations, including issues with assessment of exposure to selenium and to its various chemical forms, heterogeneity, confounding and other biases. Conflicting results including inverse, null and direct associations have been reported for some cancer types.RCTs assessing the effects of selenium supplementation on cancer risk have yielded inconsistent results, although the most recent studies, characterised by a low risk of bias, found no beneficial effect on cancer risk, more specifically on risk of prostate cancer, as well as little evidence of any influence of baseline selenium status. Rather, some trials suggest harmful effects of selenium exposure. To date, no convincing evidence suggests that selenium supplements can prevent cancer in humans.

Recruiting Chinese Americans into cancer screening intervention trials: strategies and outcomes

BACKGROUND

Cancer is the leading cause of death among Asian Americans. While Asian Americans are the fastest growing minority population in the United States, they are underrepresented in cancer research and report poor adherence to cancer screening guidelines.

PURPOSE

This study utilized data from two large randomized intervention trials to evaluate strategies to recruit first-generation Chinese American immigrants from community settings and Chinese American physician practices. Findings will inform effective strategies for promoting Asian American participation in cancer control research.

METHODS

Chinese Americans who were non-adherent to annual mammography screening guidelines (Study 1 with 664 immigrant women > 40 years of age) and to colorectal cancer screening guidelines (Study 2 with 455 immigrants > 50 years of age) were enrolled from the greater Washington DC, New York City (NYC), and Philadelphia (PA) areas. Both studies trained bilingual staff to enroll Chinese-speaking participants with the aid of linguistically appropriate fliers and brochures to obtain consent. Study 1 adopted community approaches and worked with community organizations to enroll participants. Study 2 randomly selected potential participants through 24 Chinese American primary-care physician offices, and mailed letters from physicians to enroll patients, followed by telephone calls from research staff. The success of recruitment approaches was assessed by yield rates based on number of participants approached, ineligible, and consented.

RESULTS

Most participants (70%) of Study 1 were enrolled through in-person community approaches (e.g., Chinese schools, stores, health fairs, and personal networks). The final yield of specific venues differed widely (6% to 100%) due to various proportions of ineligible subjects (2%-64%) and refusals (0%-92%). The Study 2 recruitment approach (physician letter followed by telephone calls) had different outcomes in two geographic areas, partially due to differences in demographic characteristics in the DC and NYC/PA areas. The community approaches enrolled more recent immigrants and uninsured Chinese Americans than the physician and telephone call approach (p < .001). Enrollment cost is provided to inform future research studies.

LIMITATIONS

Our recruitment outcomes might not be generalizable to all Chinese Americans or other Asian American populations because they may vary by study protocols (e.g., length of trials), target populations (i.e., eligibility criteria), and available resources.

CONCLUSIONS

Use of multiple culturally relevant strategies (e.g., building trusting relationships through face-to-face enrollment, use of bilingual and bicultural staff, use of a physician letter, and employing linguistically appropriate materials) was crucial for successfully recruiting a large number of Chinese Americans in community and clinical settings. Our data demonstrate that substantial effort is required for recruitment; studies need to budget for this effort to ensure the inclusion of Asian Americans in health research.

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.

A systematic review of the factors influencing African Americans' participation in cancer clinical trials

OBJECTIVE

This systematic review was conducted to synthesize the existing evidence regarding key considerations influencing African Americans' participation in cancer clinical trials (CCTs).

METHODS

The PubMed and PsycINFO databases were searched to identify peer-reviewed publications during the last decade (2002-2011) that met our inclusionary criteria. Our search utilized Boolean combinations of the following terms: "clinical trial"; "cancer"; "neoplasm"; "African American"; "Black"; "caregiver"; "decision making"; "recruitment"; "companion"; "family"; "significant other"; and "social support".

RESULTS

A total of 267 articles were identified in the database searches. Of these articles, a total of 31 were determined to meet the inclusion criteria and were retained for review. Key issues that emerged as impediments to a successful recruitment of African Americans to CCTs included negative attitudes towards clinical trials, low levels of knowledge and awareness regarding CCTs, religious beliefs, and structural barriers, such as transportation, childcare, and access to health care. Recommendations from physicians, family members, and friends may promote CCT participation. Multimedia, and culturally-appropriate recruitment approaches may also be effective in soliciting participation among African Americans.

CONCLUSION

Existing research underscores the importance of social support from family and friends, cultural appropriateness and sensitivity from physicians and in the design of the CCT, and enhanced education among African Americans in decision-making processes. As African Americans are underrepresented in CCTs, targeted strategies to enhance recruitment efforts and improve cancer treatment outcomes are essential.

National Surgical Adjuvant Breast and Bowel Project Study of Tamoxifen and Raloxifene trial: advancing the science of recruitment and breast cancer risk assessment in minority communities

BACKGROUND

One of the first chemoprevention trials conducted in the western hemisphere, the National Surgical Adjuvant Breast and Bowel Project's (NSABP) Breast Cancer Prevention Trial (BCPT), demonstrated the need to evaluate all aspects of recruitment in real time and to implement strategies to enroll racial and ethnic minority women.

PURPOSE

The purpose of this report is to review various patient recruitment efforts the NSABP developed to enhance the participation of racial and ethnic minority women in the Study of Tamoxifen and Raloxifene (STAR) trial and to describe the role that the recruitment process played in the implementation and understanding of breast cancer risk assessment in minority communities.

METHODS

The NSABP STAR trial was a randomized, double-blinded study comparing the use of tamoxifen 20 mg/day to raloxifene 60 mg/day, for a 5-year period, to reduce the risk of developing invasive breast cancer. Eligible postmenopausal women were required to have a 5-year predicted breast cancer risk of 1.66% based on the modified Gail Model. For the current report, eligibility and enrollment data were tabulated by race/ethnicity for women who submitted STAR risk assessment forms (RAFs).

RESULTS

A total of 184,460 RAFs were received, 145,550 (78.9%) from white women and 38,910 (21.1%) from minority women. Of the latter group, 21,444 (11.6%) were from African Americans/blacks, 7913 (4.5%) from Hispanics/Latinas, and 9553 (5.2%) from other racial or ethnic groups. The percentages of risk-eligible women among African Americans, Hispanics/Latinas, others, and whites were 14.2%, 23.3%, 13.7%, and 57.4%, respectively. Programs targeting minority enrollment submitted large numbers of RAFs, but the eligibility rates of the women referred from those groups tended to be lower than the rates among women referred outside of those programs. The average number of completed risk assessments increased among minority women over the course of the recruitment period compared to those from whites.

LIMITATIONS

We have not addressed all identified barriers to the recruitment of minorities in clinical research. Our risk assessments and recruitment results do not reflect the modified Gail Model for African Americans.

CONCLUSIONS

Recruitment strategies used in STAR for racial and ethnic minorities contributed to doubling the minority enrollment compared to that in the BCPT and increased the awareness of breast cancer risk assessment in minority communities. Incorporation of new information into models to improve the risk estimation of diverse populations should prove beneficial.

Recruiting a special sample with sparse resources: lessons from a study of Gulf War veterans

BACKGROUND

Recruitment is the most common failure point for clinical studies, with recruitment failure adversely affecting science, dollar costs, human capital, and the ethical risk-benefit trade-off to study participants. Added problems attend recruitment of special and/or challenging candidate populations, particularly in settings of sparse recruitment resources. Obstacles to study recruitment and participation of ill Gulf War veterans (GWVs) include health barriers, work and family obligations, mistrust of the medical/scientific community, and challenges to identifying/reaching potential participants.

PURPOSE

We sought to identify and implement a minimal-cost multipronged recruitment approach for a small single-site (<50 participants) study of a special group, ill GWVs, with approaches substantially applicable to other recruitment settings and larger multisite studies.

METHODS

Categories of recruitment approach included directed as well as general media, collaborations with support groups/interest groups, local free advertising resources (Craigslist and Backpage), physician outreach, Internet-based approaches, and referrals from study participants and screenees. We describe the subcategories and yield of each approach within each approach.

RESULTS

Each approach contributed candidates to the final recruitment tally, with the largest fractional contribution by directed media (52%). Among the remainder, no other individual approach was clearly dominant (largest contribution: 13%).

LIMITATIONS

Special population subsamples present special challenges; all approaches cited may not be useful in all settings and subpopulations.

CONCLUSIONS

A multipronged suite of minimal-cost approaches led to successful recruitment to target for this single-site clinical trial for a special population with significant recruitment challenges. It additionally yielded a nation-wide corpus of several hundred individuals interested in participation in future studies of GWVs. While certain approaches produced disproportionate yield, it was not possible to predict these a priori. We suggest that this model, which incorporates a suite of approaches, and delineates backup approaches in the event of recruitment shortfall, may provide a template applicable to recruitment of other special samples in settings of limited resources and also is germane to cost-effective recruitment in studies more generally.

Recruitment strategy cost and impact on minority accrual to a breast cancer prevention trial

BACKGROUND

Recruitment of minorities to cancer prevention trials is difficult and costly. Early-phase cancer prevention trials have fewer resources to promote recruitment. Identifying cost-effective strategies that can replace or supplement traditional recruitment methods and improve minority accrual to small, early-phase cancer prevention trials are of critical importance.

PURPOSE

To compare the costs of accrual strategies used in a small breast cancer prevention trial and assess their impact on recruitment and minority accrual.

METHODS

A total of 1196 potential subjects with a known recruitment source contacted study coordinators about the SOY study, a breast cancer prevention trial. Recruitment strategies for this study included recruitment from within the Northwestern University network (internal strategy), advertisements placed on public transportation (Chicago Transit Authority (CTA)), health-related events, media (print/radio/television), and direct mail. Total recruitment strategy cost included the cost of study personnel and material costs calculated from itemized receipts. Incremental cost-effectiveness ratios (ICERs) were calculated to compare the relative cost-effectiveness of each recruitment strategy. If a strategy was more costly and less effective than its comparator, then that strategy was considered dominated. Scenarios that were not dominated were compared. The primary effectiveness measure was the number of consents. Separate ICERs were calculated using the number of minority consents as the effectiveness measure.

RESULTS

The total cost of SOY study recruitment was US$164,585, which included the cost of materials (US$26,133) and personnel (US$138,452). The internal referral strategy was the largest source of trial contacts (748/1196; 63%), consents (107/150; 71%), and minority consents (17/34; 50%) and was the most expensive strategy (US$139,033). CTA ads generated the second largest number of trial contacts (326/1196; 27%), the most minority contacts (184/321; 57%), and 16 minority consents (16/34; 47%), at a total cost of US$15,562. The other three strategies yielded many fewer contacts and consents. The methods of health events, CTA ads, and the internal strategy showed some evidence of cost-effectiveness (ICER: US$581, US$717, and US$1524, respectively). The CTA strategy was the most cost-effective strategy for minority accrual (ICER: US$908).

LIMITATIONS

Recall bias may have limited the accuracy of estimated time spent on recruitment by study personnel. Also, costs spent specifically on minority accrual were unobtainable; results may not be generalizable to other settings; and cost-effectiveness data for the methods of media, health events, and direct mail should be interpreted with caution since these methods generated few consents.

CONCLUSIONS

Public transportation ads have the potential to generate numerous minority contacts and consents at a reasonable cost within an urban setting. Combined with traditional methods of recruitment, this method can lead to timelier study completion and increased minority accrual. Future research should prospectively track recruitment and costs in order to better assess the cost-effectiveness of recruitment methods used to target minority populations.

Developing partnerships and recruiting dyads for a prostate cancer informed decision making program: lessons learned from a community-academic-clinical team

Prostate cancer (PrCA) is the most commonly diagnosed non-skin cancer among men. PrCA mortality in African-American (AA) men in South Carolina is ~50% higher than for AAs in the U.S as a whole. AA men also have low rates of participation in cancer research. This paper describes partnership development and recruitment efforts of a Community-Academic-Clinical research team for a PrCA education intervention with AA men and women that was designed to address the discordance between high rates of PrCA mortality and limited participation in cancer research. Guided by Vesey's framework on recruitment and retention of minority groups in research, recruitment strategies were selected and implemented following multiple brainstorming sessions with partners having established community relationships. Based on findings from these sessions culturally appropriate strategies are recommended for recruiting AA men and women for PrCA education research. Community-based research recruitment challenges and lessons learned are presented.

Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases

BACKGROUND

Our systematic review has demonstrated that antioxidant supplements may increase mortality. We have now updated this review.

OBJECTIVES

To assess the beneficial and harmful effects of antioxidant supplements for prevention of mortality in adults.

SEARCH METHODS

We searched The Cochrane Library, MEDLINE, EMBASE, LILACS, the Science Citation Index Expanded, and Conference Proceedings Citation Index-Science to February 2011. We scanned bibliographies of relevant publications and asked pharmaceutical companies for additional trials.

SELECTION CRITERIA

We included all primary and secondary prevention randomised clinical trials on antioxidant supplements (beta-carotene, vitamin A, vitamin C, vitamin E, and selenium) versus placebo or no intervention.

DATA COLLECTION AND ANALYSIS

Three authors extracted data. Random-effects and fixed-effect model meta-analyses were conducted. Risk of bias was considered in order to minimise the risk of systematic errors. Trial sequential analyses were conducted to minimise the risk of random errors. Random-effects model meta-regression analyses were performed to assess sources of intertrial heterogeneity.

MAIN RESULTS

Seventy-eight randomised trials with 296,707 participants were included. Fifty-six trials including 244,056 participants had low risk of bias. Twenty-six trials included 215,900 healthy participants. Fifty-two trials included 80,807 participants with various diseases in a stable phase. The mean age was 63 years (range 18 to 103 years). The mean proportion of women was 46%. Of the 78 trials, 46 used the parallel-group design, 30 the factorial design, and 2 the cross-over design. All antioxidants were administered orally, either alone or in combination with vitamins, minerals, or other interventions. The duration of supplementation varied from 28 days to 12 years (mean duration 3 years; median duration 2 years). Overall, the antioxidant supplements had no significant effect on mortality in a random-effects model meta-analysis (21,484 dead/183,749 (11.7%) versus 11,479 dead/112,958 (10.2%); 78 trials, relative risk (RR) 1.02, 95% confidence interval (CI) 0.98 to 1.05) but significantly increased mortality in a fixed-effect model (RR 1.03, 95% CI 1.01 to 1.05). Heterogeneity was low with an I(2)- of 12%. In meta-regression analysis, the risk of bias and type of antioxidant supplement were the only significant predictors of intertrial heterogeneity. Meta-regression analysis did not find a significant difference in the estimated intervention effect in the primary prevention and the secondary prevention trials. In the 56 trials with a low risk of bias, the antioxidant supplements significantly increased mortality (18,833 dead/146,320 (12.9%) versus 10,320 dead/97,736 (10.6%); RR 1.04, 95% CI 1.01 to 1.07). This effect was confirmed by trial sequential analysis. Excluding factorial trials with potential confounding showed that 38 trials with low risk of bias demonstrated a significant increase in mortality (2822 dead/26,903 (10.5%) versus 2473 dead/26,052 (9.5%); RR 1.10, 95% CI 1.05 to 1.15). In trials with low risk of bias, beta-carotene (13,202 dead/96,003 (13.8%) versus 8556 dead/77,003 (11.1%); 26 trials, RR 1.05, 95% CI 1.01 to 1.09) and vitamin E (11,689 dead/97,523 (12.0%) versus 7561 dead/73,721 (10.3%); 46 trials, RR 1.03, 95% CI 1.00 to 1.05) significantly increased mortality, whereas vitamin A (3444 dead/24,596 (14.0%) versus 2249 dead/16,548 (13.6%); 12 trials, RR 1.07, 95% CI 0.97 to 1.18), vitamin C (3637 dead/36,659 (9.9%) versus 2717 dead/29,283 (9.3%); 29 trials, RR 1.02, 95% CI 0.98 to 1.07), and selenium (2670 dead/39,779 (6.7%) versus 1468 dead/22,961 (6.4%); 17 trials, RR 0.97, 95% CI 0.91 to 1.03) did not significantly affect mortality. In univariate meta-regression analysis, the dose of vitamin A was significantly associated with increased mortality (RR 1.0006, 95% CI 1.0002 to 1.001, P = 0.002).

AUTHORS' CONCLUSIONS

We found no evidence to support antioxidant supplements for primary or secondary prevention. Beta-carotene and vitamin E seem to increase mortality, and so may higher doses of vitamin A. Antioxidant supplements need to be considered as medicinal products and should undergo sufficient evaluation before marketing.

Serum selenium and single-nucleotide polymorphisms in genes for selenoproteins: relationship to markers of oxidative stress in men from Auckland, New Zealand

There is controversy as to the recommended daily intake of selenium (Se), and whether current New Zealand diets are adequate in this nutrient. Various functional single-nucleotide polymorphisms (SNPs) polymorphisms may affect the efficacy of Se utilisation. These include the glutathione peroxidases GPx1 rs1050450, GPx4 rs713041, as well as selenoproteins SEPP1 rs3877899, SEL15 rs5845, SELS rs28665122 and SELS rs4965373. This cross-sectional study measured serum Se levels of 503 healthy Caucasian men in Auckland, New Zealand, between ages 20-81. The Se distribution was compared with activities of the antioxidant enzymes glutathione peroxidase and thioredoxin reductase, and DNA damage as measured by the single cell gel electrophoresis assay, both without and with a peroxide-induced oxidative challenge. Serum Se was measured using inductively coupled plasma-dynamic reaction cell-mass spectrometry, while selenoprotein SNPs were estimated using TaqMan(®) SNP genotyping assays. While antioxidant enzyme activities and DNA damage recorded after a peroxide challenge increased with increasing serum selenium, the inherent DNA damage levels in leukocytes showed no statistically significant relationship with serum selenium. However, these relationships and dietary Se requirements at the individual level were modified by several different SNPs in genes for selenoproteins. The GPx1 rs1050450 C allele was significantly associated with GPx activity. Significant correlations between serum Se level and GPX activity were seen with all genotypes except for homozygous minor allele carriers, while the GPx1 rs1050450 CT genotype showed the highest correlation. Several genotypes showed significant correlations between serum Se and TR activity with SEPP1 rs3877899 GG genotype showing the highest correlation. A significant decreasing trend in DNA damage with increasing serum Se was seen among GPx1 rs1050450 CC and GPx4 rs713041 TT genotype carriers up to a serum Se level of 116 and 149 ng/ml, respectively. In the absence of this genetic information, we would recommend a serum Se concentration in the region of 100-150 ng/ml as providing a useful compromise.

Rationale and methods for site selection for a trial using a novel intervention to treat stimulant abuse

Although the selection of appropriate clinical sites has a significant impact on the successful conduct of clinical trials, no generally accepted model is available for site selection. Use of an appropriate site selection process is even more pertinent when conducting large scale, practical clinical trials in practice settings. This report provides a rationale for selecting sites by identifying both a set of basic site selection criteria important to most trials as well as criteria specific to the features of a particular study's design. In this two-tier system, although all these criteria must be met, some criteria are firm and viewed as essential for a site to conduct the trial. Other criteria, such as those that support study recruitment or participant retention, are flexible. These flexible criteria may be addressed through several alternative solutions that meet the original intent of the criterion. We illustrate how the study specific features and requirements of Stimulant Reduction Intervention using Dosed Exercise (STRIDE), a multisite clinical trial evaluating the efficacy of exercise or health education, added to treatment as usual for stimulant abuse are linked to firm and flexible site selection criteria. We also present an iterative, multi-step approach to site selection including building awareness about the study and screening and evaluating sites using these criteria. This simple model could maximize the chance that selected sites will implement a study successfully and achieve trial aims. It may be helpful to researchers who are developing criteria and methods for site selection for specific clinical trials.

Selenium for preventing cancer

BACKGROUND

Selenium is a trace element essential to humans. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancers.

OBJECTIVES

Two research questions were addressed in this review: What is the evidence for1. an aetiological relationship between selenium exposure and cancer risk in women and men?2. the efficacy of selenium supplementation for cancer prevention in women and men?

SEARCH STRATEGY

We searched electronic databases and bibliographies of reviews and included publications.

SELECTION CRITERIA

We included prospective observational studies to answer research question (a) and randomised controlled trials (RCTs) to answer research question (b).

DATA COLLECTION AND ANALYSIS

We conducted random effects meta-analyses of epidemiological data when five or more studies were retrieved for a specific outcome. We made a narrative summary of data from RCTs.

MAIN RESULTS

We included 49 prospective observational studies and six RCTs. In epidemiologic data, we found a reduced cancer incidence (summary odds ratio (OR) 0.69 (95% confidence interval (CI) 0.53 to 0.91) and mortality (OR 0.55, 95% CI 0.36 to 0.83) with higher selenium exposure. Cancer risk was more pronouncedly reduced in men (incidence: OR 0.66, 95% CI 0.42 to 1.05) than in women (incidence: OR 0.90, 95% CI 0.45 to 1.77). These findings have potential limitations due to study design, quality and heterogeneity of the data, which complicated the interpretation of the summary statistics.The RCTs found no protective efficacy of selenium yeast supplementation against non-melanoma skin cancer or L-selenomethionine supplementation against prostate cancer. Study results for the prevention of liver cancer with selenium supplements were inconsistent and studies had an unclear risk of bias. The results of the Nutritional Prevention of Cancer Trial (NPCT) and SELECT raised concerns about possible harmful effects of selenium supplements.

AUTHORS' CONCLUSIONS

No reliable conclusions can be drawn regarding a causal relationship between low selenium exposure and an increased risk of cancer. Despite evidence for an inverse association between selenium exposure and the risk of some types of cancer, these results should be interpreted with care due to the potential limiting factors of heterogeneity and influences of unknown biases, confounding and effect modification.The effect of selenium supplementation from RCTs yielded inconsistent results. To date, there is no convincing evidence that selenium supplements can prevent cancer in men, women or children.

Nutrigenetics, nutrigenomics, and selenium

Selenium (Se) is an important micronutrient that, as a component of selenoproteins, influences oxidative and inflammatory processes. Its’ levels vary considerably, with different ethnic and geographic population groups showing varied conditions, ranging from frank Se deficiencies to toxic effects. An optimum Se level is essential for the maintenance of homeostasis, and this optimum may vary according to life stage, general state of health, and genotype. Nutrigenetic studies of different Se levels, in the presence of genetic variants in selenoproteins, suggest that an effective dietary Se intake for one individual may be very different from that for others. However, we are just starting to learn the significance of various genes in selenoprotein pathways, functional variants in these, and how to combine such data from genes into pathways, alongside dietary intake or serum levels of Se. Advances in systems biology, genetics, and genomics technologies, including genetic/genomic, epigenetic/epigenomic, transcriptomic, proteomic, and metabolomic information, start to make it feasible to assess a comprehensive spectrum of the biological activity of Se. Such nutrigenomic approaches may prove very sensitive biomarkers of optimal Se status at the individual or population level. The premature cessation of a major human Se intervention trial has led to considerable controversy as to the value of Se supplementation at the population level. New websites provide convenient links to current information on methodologies available for nutrigenetics and nutrigenomics. These new technologies will increasingly become an essential tool in optimizing the level of Se and other micronutrients for optimal health, in individuals and in population groups. However, definitive proof of such effects will require very large collaborative studies, international agreement on study design, and innovative approaches to data analysis.

Impact and costs of targeted recruitment of minorities to the National Lung Screening Trial

BACKGROUND

To promote results in the National Lung Screening Trial (NLST) that are generalizable across the entire US population, a subset of NLST sites developed dedicated strategies for minority recruitment.

PURPOSE

To report the effects of targeted strategies on the accrual of underrepresented groups, to describe participant characteristics, and to estimate the costs of targeted enrollment.

METHODS

The 2002-2004 Tobacco Use Supplement was used to estimate eligible proportions of racial and ethnic categories. Strategic planning included meetings/conferences with key stakeholders and minority organizations. Potential institutions were selected based upon regional racial/ethnic diversity and proven success in recruitment of underrepresented groups. Seven institutions submitted targeted recruitment strategies with budgets. Accrual by racial/ethnic category was tracked for each institution. Cost estimates were based on itemized receipts for minority strategies relative to minority accrual.

RESULTS

Of 18,842 participants enrolled, 1576 (8.4%) were minority participants. The seven institutions with targeted recruitment strategies accounted for 1223 (77.6%) of all minority participants enrolled. While there was a significant increase in the rate of minority accrual pre-implementation to post-implementation for the institutions with targeted recruitment (9.3% vs. 15.2%, p <  0.0001), there was no significant difference for the institutions without (3.5% vs. 3.8%, p = 0.46). Minority enrollees at the seven institutions tended to have less than a high school education, be economically disadvantaged, and were more often uninsured. These socio-demographic differences persisted at the seven institutions even after adjusting for race and ethnicity. The success of different strategies varied by institution, and no one strategy was successful across all institutions. Costs for implementation were also highly variable, ranging from $146 to $749 per minority enrollee.

LIMITATIONS

Data on minority recruitment processes were not consistently kept at the individual institutions. In addition, participant responses via newspaper advertisements and the efforts of minority staff hired by the institutions could not be coded on Case Report Forms.

CONCLUSIONS

Strategic efforts were associated with significant increases in minority enrollment. The greatest successes require that a priori goals be established based on eligible racial/ethnic proportions; the historical performance of sites in minority accrual should factor into the selection of sites; recruitment planning must begin well in advance of trial launch; and there must be endorsement by prominent representatives of the racial groups of interest.

A nutrient approach to prostate cancer prevention: The Selenium and Vitamin E Cancer Prevention Trial (SELECT)

The Selenium and Vitamin E Cancer Prevention Trial (SELECT) randomized 35,533 healthy men, >55 yr old (>50 yr if African American), with normal digital rectal exams and prostate specific antigens <4 ng/ml to 1) 200 μg/day l-selenomethionine, 2) 400 IU/day all-rac-alpha-tocopheryl acetate (vitamin E), 3) both supplements, or 4) placebo for 7 to 12 yr. The hypotheses underlying SELECT, that selenium and vitamin E individually and together decrease prostate cancer incidence, derived from epidemiologic and laboratory evidence and significant secondary endpoints in the Nutritional Prevention of Cancer (selenium) and Alpha-Tocopherol Beta-Carotene (vitamin E) trials. In SELECT, prostate cancer incidence did not differ among the 4 arms: hazard ratios [99% confidence intervals (CIs)] for prostate cancer were 1.13 (99% CI = 0.95-1.35, P = 0.06; n = 473) for vitamin E, 1.04 (99% CI = 0.87-1.24, P = 0.62; n = 432) for selenium, and 1.05 (99% CI = 0.88-1.25, P = 0.52; n = 437) for selenium + vitamin E vs. 1.00 (n = 416) for placebo. Statistically nonsignificant increased risks of prostate cancer with vitamin E alone [relative risk (RR) = 1.13, P = 0.06) and newly diagnosed Type 2 diabetes mellitus with selenium alone (RR = 1.07, P = 0.16) were observed. SELECT data show that neither selenium nor vitamin E, alone or together, in the doses and formulations used, prevented prostate cancer in this heterogeneous population of healthy men.

Translating research into evidence-based practice: the National Cancer Institute Community Clinical Oncology Program

The recent rapid acceleration of basic science is reshaping both our clinical research system and our healthcare delivery system. The pace and growing volume of medical discoveries are yielding exciting new opportunities, yet we continue to face old challenges to maintain research progress and effectively translate research into practice. The National Institutes of Health and individual government programs increasingly are emphasizing research agendas that involve evidence development, comparative-effectiveness research among heterogeneous populations, translational research, and accelerating the translation of research into evidence-based practice as well as building successful research networks to support these efforts. For more than 25 years, the National Cancer Institute Community Clinical Oncology Program has successfully extended research into the community and facilitated the translation of research into evidence-based practice. By describing its keys to success, this article provides practical guidance to cancer-focused, provider-based research networks as well as those in other disciplines.

Impact of supplemental site grants to increase African American accrual for the Selenium and Vitamin E Cancer Prevention Trial

BACKGROUND

African American accrual to prevention trials at rates representative of the disease burden experienced by this population requires additional resources and focused efforts.

PURPOSE

To describe the rationale, context, and criteria for selection of sites that received Minority Recruitment Enhancement Grants (MREGs) to increase African American recruitment to the Selenium and Vitamin E Cancer Prevention Trial (SELECT). To determine if African American accrual was higher among the 15 MREG sites when compared with similar nonawarded sites.

METHODS

Changes in African American accrual at sites that received MREGs are compared with changes in a group of 15, frequency-matched, nonawarded sites using a quasi-experimental, post hoc analysis. Successful and unsuccessful recruitment strategies reported by the MREG sites are described.

RESULTS

The increased number of African American participants accrued per month at MREG sites post-funding was higher than the change at comparison sites by a factor of 3.38 (p = 0.004, 95% CI: 1.51-7.57). An estimated 602 additional African American participants were recruited at MREG sites due to MREG funding, contributing to the overall 14.9% African American recruitment. Successful recruitment strategies most reported by MREG sites included increasing staff, transportation resources, recruiting through the media, mailings, and prostate cancer screening clinics during off-hours.

LIMITATIONS

Comparison sites were chosen retrospectively, not by randomization. Although comparison sites were selected to be similar to MREG sites with regard to potential confounding factors, it is possible that unknown factors could have biased results. Cost-effective analyses were not conducted.

CONCLUSIONS

MREG sites increased African American accrual in the post-funding period more than comparison sites, indicating MREG funding enhanced the sites' abilities to accrue African American participants. Targeted grants early in the accrual period may be a useful multi-site intervention to increase African American accrual for a prevention study where adequate African American representation is essential.

Recruitment of a racially and ethnically diverse sample into a physical activity efficacy trial

BACKGROUND

Healthy People 2010 underscores the relevance of eliminating health disparities. Thus, it is paramount to create interventions that promote health for all individuals.

PURPOSE

This study examined differences in rates of and reasons for ineligibility among non-Hispanic blacks and whites in a randomized controlled physical activity intervention study.

METHODS

Participants (1245 adults) responded to community advertising for the research study. Eligibility at the four pre-randomization assessment sessions was determined by self-reported medical information, resting EKG, 7-Day Physical Activity Recall, fitness test and Stage of Change. We used t-tests to examine the rates of eligibility among participant subgroups.

RESULTS

Blacks had higher rates of overall ineligibility (86.9%) than whites (75.1%; p < 0.01) and were more likely to be ineligible due to lack of interest or no-show at a pre-randomization appointment (35.4% vs. 24.3%; p < 0.01). Blacks were more likely to be ineligible for medical reasons after the telephone screen (16.3% vs. 7.8%; p = 0.01).

LIMITATIONS

This study did not use a random sampling of potential participants from each of the racial/ethnic groups and thus, there is the potential for selection bias.

CONCLUSIONS

Blacks were more likely to choose not to enroll in the study due to a lack of interest, but had similar rates of overall medical ineligibility to whites. This highlights the importance of strategies that enhance interest among blacks, who initially respond to recruitment advertising.

Recruitment of minority and underserved populations in the United States: the Centers for Population Health and Health Disparities experience

OBJECTIVE

The recruitment of minority and underserved individuals to research studies is often problematic. The purpose of this study was to describe the recruitment experiences of projects that actively recruited minority and underserved populations as part of The Centers for Population Health and Health Disparities (CPHHD) initiative.

METHODS

Principal investigators and research staff from 17 research projects at eight institutions across the United States were surveyed about their recruitment experiences. Investigators reported the study purpose and design, recruitment methods employed, recruitment progress, problems or challenges to recruitment, strategies used to address these problems, and difficulties resulting from Institutional Review Board (IRB) or Health Insurance Portability and Accountability Act of 1996 (HIPAA) requirements. Additionally, information was collected about participant burden and compensation. Burden was classified on a three-level scale. Recruitment results were reported as of March 31, 2007.

RESULTS

Recruitment attainment ranged from 52% to 184% of the participant recruitment goals. Commonly reported recruitment problems included administrative issues, and difficulties with establishing community partnerships and contacting potential participants. Long study questionnaires, extended follow-up, and narrow eligibility criteria were also problematic. The majority of projects reported difficulties with IRB approvals, though few reported issues related to HIPAA requirements. Attempted solutions to recruitment problems varied across Centers and included using multiple recruitment sites and sources and culturally appropriate invitations to participate. Participant burden and compensation varied widely across the projects, however, accrual appeared to be inversely associated with the amount of participant burden for each project.

CONCLUSION

Recruitment of minority and underserved populations to clinical trials is necessary to increase study generalizbility and reduce health disparities. Our results demonstrate the importance of flexible study designs which allow adaptation to recruitment challenges. These experiences also highlight the importance of involving community members and reducing participant burden to achieve success in recruiting individuals from minority and underserved populations.

Minority enrollment in Parkinson's disease clinical trials

Under-representation of minorities in clinical trials limits access to information relevant to all segments of the population. We assessed the enrollment of minority subjects with Parkinson's disease (PD) into clinical trials. We searched PubMed for published studies of PD trials conducted in the US over the past 20 years and found that only 41 reported racial/ethnic participation (17%). In those trials reporting race/ethnicity, 8% of subjects were non-white, compared to 20% of the non-white US population over age 60. Results of this study identified the need for better reporting of racial composition in clinical trials and for the enrollment of more minority participants in research studies.

Enrollment of racial and ethnic minorities in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial

BACKGROUND

Minority populations in the United States, especially blacks and Hispanics, are generally underrepresented among participants in clinical trials. Here, we report the experience of enrolling ethnic minorities in a large cancer screening trial.

METHODS

The Prostate, Colorectal, Lung and Ovarian (PLCO) Cancer Screening Trial is a multicenter randomized trial designed to evaluate the effectiveness of screening for the PLCO cancers. Subjects were recruited at 10 U.S. centers between 1993 and 2001. One screening center had a major special recruitment effort for blacks and another center had a major special recruitment effort for Hispanics.

RESULTS

Among almost 155,000 subjects enrolled in PLCO, minority enrollment was as follows: black (5.0%), Hispanic (1.8%) and Asian (3.6%). This compares to an age-eligible population in the combined catchment areas of the PLCO centers that was 14.0% black, 2.9% Hispanic and 5.4% Asian, and an age-eligible population across the U.S. that was 9.5% black, 6.5% Hispanic and 3.0% Asian. About half (45%) of Hispanics were recruited at the center with the special Hispanic recruitment effort. Seventy percent of blacks were recruited at two centers; the one with the major special recruitment effort and a center in Detroit whose catchment area was 20% black among age-eligibles. Blacks, Hispanics and (non-Hispanic) whites were all more highly educated, less likely to currently smoke and more likely to get regular exercise than their counterparts in the general population.

CONCLUSION

Significant efforts were made to recruit racial/ ethnic minorities into PLCO, and these efforts resulted in enrollment levels that were comparable to those seen in many recent cancer screening or prevention trials. Blacks and Hispanics were nonetheless underrepresented in PLCO compared to their levels among age-eligibles in the overall U.S. population or in the aggregate PLCO catchment areas.

Barriers to recruiting underrepresented populations to cancer clinical trials: a systematic review

Racial and ethnic minorities, older adults, rural residents, and individuals of low socioeconomic status are underrepresented among participants in cancer-related trials. The authors conducted a systematic review to determine the barriers to participation of underrepresented populations in cancer-related trials. Their search included English-language publications that reported original data on the recruitment of underrepresented groups to cancer treatment or prevention trials between 1966 and December 2005 in multiple electronic databases. They also hand-searched titles in 34 journals from January 2003 to December 2005 and they examined reference lists for eligible articles. Titles and abstracts were reviewed to identify relevant studies. Data on barriers to participation were synthesized both qualitatively and based on statistically significant associations with trial enrollment. Of 5257 studies that were cited, 65 studies were eligible for inclusion in the current analysis, including 46 studies on recruitment into cancer therapeutic trials, 15 studies on recruitment into prevention trials, and 4 studies on recruitment into both prevention and treatment trials. Numerous factors were reported as barriers to participation in cancer-related trials. However, only 20 of the studies reported statistically significant associations between hypothesized barriers and enrollment. The available evidence had limitations in quality regarding representativeness, justification of study methods, the reliability and validity of data-collection methods, potential for bias, and data analysis. The results indicated that underrepresented populations face numerous barriers to participation in cancer-related trials. The current systematic review highlighting the literature on recruitment of underrepresented populations to cancer trials and may be used as the evidence base toward developing an agenda for etiologic and intervention research to reduce the disparities in participation in cancer-related trials.

Recruiting low-income healthy women to research: an exploratory study

OBJECTIVE

The study goals were (1) to assess the feasibility of using an existing telephone health information and referral service for low-income, ethnically diverse women to recruit women for research participation; (2) to assess the feasibility of recruiting low-income, African American and Latino men into health research through the women callers to the telephone service; and (3) to describe the challenges women face and the strategies they use when talking to men about the men's health and research participation.

DESIGN

We recruited women for individual semi-structured qualitative interviews via the Every Woman Counts (EWC) telephone information and referral service, a California Department of Health Services Cancer Detection Program. This paper describes our eligibility and recruitment assessment, and our qualitative data from 23 interviews with low-income African American and Latino women who called EWC.

RESULTS

We found that it was feasible to recruit women, but not to recruit men through women who call this telephone service. Almost 50% (113) of women demographically eligible for recruitment, completed our screening questionnaire, despite calling EWC for a different purpose. Some 48% (54) of those women were eligible for an interview. Of interview-eligible women, 58% (10) of African Americans and 35% (13) of Latinos completed an interview. Only 17% (4) of women referred a man for participation in an interview for our study. Several themes emerged from our analysis of interview data: (1) women's role in men's health can be significant but is often uneasy; (2) challenges when talking to men about their health include health access, gender dynamics, and men's fear of health care; (3) women's understanding of research may be limited; (4) women use a range of strategies to address and overcome men's resistance to taking care of their health and participating in research.

CONCLUSIONS

The challenges women face when talking with men about their health affect their ability to effectively speak to men about research participation. However, EWC and similar telephone health services may be an effective means for recruiting low-income women to chemoprevention and other studies requiring healthy participants.

Recruitment strategies in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial

The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial is a randomized, multicenter clinical trial using a double 2 x 2 factorial design in 10,251 participants with type 2 diabetes mellitus at high risk for cardiovascular disease (CVD) events. ACCORD is testing 3 complementary medical treatment strategies that may reduce high rates of major CVD morbidity and mortality in patients with type 2 diabetes. The ACCORD vanguard phase, conducted at 59 clinics in the United States and Canada, recruited 1,174 participants in 20 weeks from January through June 1, 2001, with a recruitment efficiency (R-factor) of 0.65. The recruitment strategies used in this vanguard phase were almost exclusively chart and database review within clinical practices and institutions. Recruitment for the main trial began in February 2003, involved 77 clinics, and resulted in an additional 9,077 participants by October 29, 2005 (total, 10,251). The R-factor during main trial recruitment was 0.96. Although new and refined recruitment strategies were formulated from the vanguard experience, the most powerful determinant of improved recruitment efficiency was the immediate start of enrollment by most clinics at the beginning of the main trial. Recruitment in the main trial required only a brief extension of 3 months and facilitated the nearly complete capture of the expected number of person-years of observation. Described herein are vanguard and main trial recruitment activities, including strategy implementation, screening procedures, randomization results, problems encountered, and lessons learned.

Vitamin and mineral supplements for cancer prevention: issues and evidence

Trials of nutritional supplements for cancer prevention must overcome a variety of challenges not shared in the usual paradigm of pharmaceutical agents for prevention of cardiovascular disease. Unlike for cardiovascular disease, for cancer we typically do not have well-established causal risk factors as targets for intervention. Also, for most likely cancer interventions, the expected time to achieve an effect is much longer, more variable, and far less well understood than for cardiovascular disease, and the progression of pathophysiology is much harder-or impossible-to follow, in contrast with imaging for progression of atherosclerosis in cardiovascular disease. Also, cancers at various sites have a wide range of etiologies. The optimal age for intervention, best dose, and duration needed to test nutritional agents for cancer prevention are largely unknown, making null findings hard to interpret. Unlike with drugs, baseline nutritional status can be critical. Moreover, because the nutritional agents are often readily available, adherence in control groups in trials can be impaired. Several gene-nutrient and nutrient-nutrient interactions have been identified that could affect trial results. Some studies suggest that particular nutrients may be effective only in subgroups defined by genotypes or by nutritional status of another nutrient. All these challenges must be considered in planning informative trials. Long-term prospective cohort studies, especially with repeated measures and high follow-up, can provide useful data for planning trials as well as the basis for rational recommendations while awaiting trial results or in settings where trials may be infeasible.