In this study of women with breast cancer screened for a therapeutic breast cancer clinical trial at an NCI-designated cancer center in the Deep South, we found that more than half were eligible for therapeutic clinical trials. Furthermore, more than 50% of eligible patients, regardless of race, rurality, and area disadvantage, enrolled into a therapeutic clinical trial. Interestingly, there was no statistically significant difference between area disadvantage and eligibility for a clinical trial. Additionally, both crude rates of enrollment and univariate analyses demonstrated an association between higher area disadvantage and increased enrollment. While multivariable analyses did not demonstrate significance, a trend of increased likelihood of enrollment was observed. Our finding contrasts with existing literature associating lower socioeconomic status with decreased enrollment in trials.15,16,17 Financial factors and incentives could explain this, as economically vulnerable patients most commonly cite cost, including travel, missed work, and childcare, as a barrier to enrollment.18,19 While compensation and monetary incentives can enhance enrollment and accrual,20,21,22 further research is indicated to understand what specific patient-level factors are influencing participation in low income populations. Though, our research suggests that eligibility and patient acceptance of the trial may not be the primary drivers of lack of participation. It is well documented that patients from areas of higher disadvantage typically have both lower eligibility and enrollment compared with those from areas of lower disadvantage.16 This phenomenon is attributed to factors including limited access to healthcare, higher prevalence of multimorbidity, and later-stage presentation, all of which could impact the likelihood of patient eligibility.20,23 Such findings suggest that efforts to improve trial access and expand eligibility criteria may aid in including more socioeconomically diverse patients in cancer clinical trials.

We found no significant differences in trial eligibility or enrollment based on race. Furthermore, both enrollment and eligibility among Black patients at our institution was higher than the national average.10 This is particularly notable given that medical mistrust among Black patients remains significant in Alabama, due to the enduring impact of historical exploitative medical practices such as the 1932–1972 Tuskegee Syphilis study.24 Furthermore, recent literature highlights that ongoing perceived or real racism and discriminatory practices in healthcare and research exacerbate mistrust in Black patients today.24,25 Implicit bias among all medical personnel is an important consideration in the participation of minority patients, especially at our institution where 43.5% of the community we serve is Black. Specifically, physician implicit bias has been implicated as a barrier to representation of minority patients in trials, as it leads to inconsistent trial offers.26 To address this, the American Society of Clinical Oncology (ASCO) and the Association of Community Cancer Centers (ACCC) recommend internal evaluation to assess for racial and ethnic disparities in screening and referral, allowing for individualized adjustments to enhance diversity.27 Also, the ASCO and ACCC have implemented Just ASK, a training program designed to reduce physicians’ implicit bias by encouraging providers to ask all patients about trial participation. The training displayed successful results,27 and while our institution has not utilized this, it could be beneficial to increase eligibility and enrollment among all patients.

In our center, the first step to enrolling a patient on a clinical trial requires referral from a medical, surgical, or radiation oncologist. For this critical first step to occur, the physician must actively recall and identify an available trial, be familiar with the general inclusion criteria, and overcome any implicit bias. Further challenges that physicians report include time constraints, limited awareness of trials, and noncooperation from colleagues.28 Following physician referral in our center, a study coordinator takes over screening for eligibility based on specific criteria outlined in study protocols, including: laboratory values, pathologic characterizations, and comorbidity status.29 Generally, at this point, many patients are deemed ineligible due to the high prevalence of comorbidities and the extremely specific nature of trial criteria.29 Dedicated research staff are essential for this process, as providers alone may not have the capacity to manage the identification, enrollment, and follow-up.30

Our institution is fortunate to have clinical trial coordinators ultimately alleviating much of the physician burden which may account for why we did not see any significant differences in trial eligibility among various demographic groups. However, the process of screening and recruitment at our institution has room for refining and improvement. At the time of this study, mainly medical oncologists were often responsible for initiating the screening and recruiting process. They identified potential trials for their patients based on their main eligibility criteria (i.e., cancer subtype and stage), and either discussed it with the patient or referred the case to the trial coordinator for further recruitment and screening based on full trial eligibility. A database is maintained by the clinicians and research coordinators track each patient considered for a clinical trial to monitor their eligibility, consent, trial initiation, and trial termination. However, as of recently, screening for clinical trials is incorporated into our weekly multidisciplinary treatment planning meetings, where each new patient gets discussed, imaging reviewed, and preliminary plans made. This ensures that each patient is at least initially considered for a trial based on cancer type and stage, allowing for more intentional consideration of trial enrollment and ensuring that eligible patients are identified early in their treatment planning.

Similarly, we observed no significant disparities in trial enrollment based on rurality, with patients from both urban and rural areas demonstrating similar likelihoods of trial eligibility and enrollment. This finding contradicts previous literature, which cites lower trial participation rates among rural populations.31 Existing literature attributes this to factors including lack of facilities, inadequate infrastructure, inability to travel, lack of specialists, and financial barriers.32 Our findings could stem from the substantial focus on circumventing barriers to clinical trials for rural patients at our NCI-designated CCC in the Deep South. Such patients are demonstrating significant health seeking behaviors through pursuing our tertiary care. Also, many community physicians refer complex cancer patients to our center, sometimes for discussion of clinical trials when current standard of care options may be lacking or ineffective, further diversifying our patient population. While our institution has utilized cross-institutional collaborations, there remains opportunity to increase population-reflective accrual further through a more formalized community clinical trial network.33

Our study has several limitations. Our sample was drawn from a single institution located in the Deep South, which may limit the generalizability. Our database was prospectively internally maintained voluntarily by medical oncologists and study coordinators. The database was not exclusively designed for research purposes, thus may have missing or incorrect data entry. Finally, we focused exclusively on patients referred for therapeutic breast cancer trials, and findings may not generalize to other types of clinical trials or cancer populations.