Sizeable disparities exist in breast cancer outcomes, both between Black and White patients in the United States, and between patients in the United States and other high-income countries compared ...with low- and middle-income countries (LMIC). In both settings, health system factors are key drivers of disparities. In the United States, Black women are more likely to die of breast cancer than Whites and have poorer outcomes, even among patients with similar stage and tumor subtype. Over-representation of higher risk "triple-negative" breast cancers contributes to breast cancer mortality in Black women; however, the greatest survival disparities occur within the good-prognosis hormone receptor-positive (HR
) subtypes. Disparities in access to treatment within the complex U.S. health system may be responsible for a substantial portion of these differences in survival. In LMICs, breast cancer mortality rates are substantially higher than in the United States, whereas incidence continues to rise. This mortality burden is largely attributable to health system factors, including late-stage presentation at diagnosis and lack of availability of systemic therapy. This article will review the existing evidence for how health system factors in the United States contribute to breast cancer disparities, discuss methods for studying the relationship of health system factors to racial disparities, and provide examples of health system interventions that show promise for mitigating breast cancer disparities. We will then review evidence of global breast cancer disparities in LMICs, the treatment factors that contribute to these disparities, and actions being taken to combat breast cancer disparities around the world.
Purpose Racial variation in the financial impact of cancer may contribute to observed differences in the use of guideline-recommended treatments. We describe racial differences with regard to the ...financial impact of breast cancer in a large population-based prospective cohort study. Methods The Carolina Breast Cancer Study oversampled black women and women younger than age 50 years with incident breast cancer in North Carolina from 2008 to 2013. Participants provided medical records and data regarding demographics, socioeconomic status, and financial impact of cancer at 5 and 25 months postdiagnosis. We report unadjusted and adjusted financial impact at 25 months postdiagnosis by race. Results The sample included 2,494 women who completed follow-up surveys (49% black, 51% white). Since diagnosis, 58% of black women reported any adverse financial impact of cancer ( v 39% of white women; P < .001). In models adjusted for age, stage at diagnosis, and treatment received, black women were more likely to report adverse financial impact attributable to cancer (adjusted risk difference aRD, +14 percentage points; P < .001), including income loss (aRD, +10 percentage points; P < .001), health care-related financial barriers (aRD, +10 percentage points; P < .001), health care-related transportation barriers (aRD, +10 percentage points; P < .001), job loss (aRD, 6 percentage points; P < .001), and loss of health insurance (aRD, +3 percentage points; P < .001). The effect of race was attenuated when socioeconomic factors were included but remained significant for job loss, transportation barriers, income loss, and overall financial impact. Conclusion Compared with white women, black women with breast cancer experience a significantly worse financial impact. Disproportionate financial strain may contribute to higher stress, lower treatment compliance, and worse outcomes by race. Policies that help to limit the effect of cancer-related financial strain are needed.
Background
Approximately 40% of patients with cancer also have another chronic medical condition. Patient‐centered medical homes (PCMHs) have improved outcomes among patients with multiple chronic ...comorbidities. The authors first evaluated the impact of a cancer diagnosis on chronic medication adherence among patients with Medicaid coverage and, second, whether PCMHs influenced outcomes among patients with cancer.
Methods
Using linked 2004 to 2010 North Carolina cancer registry and claims data, the authors included Medicaid enrollees who were diagnosed with breast, colorectal, or lung cancer who had hyperlipidemia, hypertension, and/or diabetes mellitus. Using difference‐in‐difference methods, the authors examined adherence to chronic disease medications as measured by the change in the percentage of days covered over time among patients with and without cancer. The authors then further evaluated whether PCMH enrollment modified the observed differences between those patients with and without cancer using a differences‐in‐differences‐in‐differences approach. The authors examined changes in health care expenditures and use as secondary outcomes.
Results
Patients newly diagnosed with cancer who had hyperlipidemia experienced a 7‐percentage point to 11‐percentage point decrease in the percentage of days covered compared with patients without cancer. Patients with cancer also experienced significant increases in medical expenditures and hospitalizations compared with noncancer controls. Changes in medication adherence over time between patients with and without cancer were not determined to be statistically significantly different by PCMH status. Some PCMH patients with cancer experienced smaller increases in expenditures (diabetes) and emergency department use (hyperlipidemia) but larger increases in their inpatient hospitalization rates (hypertension) compared with non‐PCMH patients with cancer relative to patients without cancer.
Conclusions
PCMHs were not found to be associated with improvements in chronic disease medication adherence, but were associated with lower costs and emergency department visits among some low‐income patients with cancer.
The authors report that low‐income patients with cancer who have chronic conditions have worse adherence to chronic medications, higher costs, and higher health care use around the time of their cancer diagnosis. Changes in chronic medication adherence for patients with cancer compared with patients without cancer appear to be no different for those in patient‐centered medical homes. Future studies should examine a variety of approaches that can help to mitigate the multidimensional burden of cancer in low‐income populations.
Background
To the authors' knowledge, it is unknown whether patient‐reported symptom severity and symptom interference with daily activities differ between younger (aged <65 years) and older (aged ...≥65 years) women receiving similar chemotherapy regimens for early breast cancer (EBC).
Methods
Study participants rated 17 side effects of chemotherapy regimens currently in use in clinical practice (2014‐2019).
Results
Of 284 women with EBC (stage I‐III), approximately 57% were aged <65 years and 43% were aged ≥65 years. For anthracycline‐based regimens, a higher percentage of younger women reported moderate, severe, or very severe (MSVS) hot flashes (49% vs 18%) (P < .001). For nonanthracycline regimens, a higher percentage of younger women reported MSVS hot flashes (38% vs 19%) (P = .009) and a lower percentage reported MSVS arthralgia (28% vs 49%) (P = .005). With regard to symptom interference with daily activities, a higher percentage of younger women being treated with anthracycline‐based regimens reported MSVS hot flashes (32% vs 7%) (P = .001) and myalgia (38% vs 18%) (P = .02). For nonanthracycline chemotherapy, a higher percentage of younger women reported MSVS interference for hot flashes (26% vs 9%) (P = .006) and lower percentages reported abdominal pain (13% vs 28%) (P = .02). Overall, there were no significant differences noted among younger versus older patients with regard to hospitalizations (19% vs 12%; P = .19), dose reductions (34% vs 31%; P = .50), dose delays (22% vs 25%; P = .59), or early treatment discontinuation (16% vs 16%; P = .9546).
Conclusions
Older and younger women with EBC who were treated with identical chemotherapy regimens generally experienced similar levels of symptom severity, symptom‐related interference with daily activities, and adverse events.
Lay Summary
In this study, women receiving chemotherapy for early breast cancer rated the severity of 17 symptoms and symptom interference with their activities of daily living.
Older (aged ≥65 years) and younger (aged <65 years) women who received identical chemotherapy regimens generally experienced similar levels of symptom severity, symptom‐related interference with daily activities, and adverse events.
In the current study, women receiving chemotherapy for early breast cancer rate the severity of 17 symptoms and symptom interference with their activities of daily living. Older (aged ≥65 years) and younger (aged <65 years) women who received identical chemotherapy regimens generally experienced similar levels of symptom severity, symptom‐related interference with daily activities, and adverse events.
Background.
In this paper, we provide background and context regarding the potential for a new data‐sharing platform, the Project Data Sphere (PDS) initiative, funded by financial and in‐kind ...contributions from the CEO Roundtable on Cancer, to transform cancer research and improve patient outcomes. Given the relatively modest decline in cancer death rates over the past several years, a new research paradigm is needed to accelerate therapeutic approaches for oncologic diseases. Phase III clinical trials generate large volumes of potentially usable information, often on hundreds of patients, including patients treated with standard of care therapies (i.e., controls). Both nationally and internationally, a variety of stakeholders have pursued data‐sharing efforts to make individual patient‐level clinical trial data available to the scientific research community.
Potential Benefits and Risks of Data Sharing.
For researchers, shared data have the potential to foster a more collaborative environment, to answer research questions in a shorter time frame than traditional randomized control trials, to reduce duplication of effort, and to improve efficiency. For industry participants, use of trial data to answer additional clinical questions could increase research and development efficiency and guide future projects through validation of surrogate end points, development of prognostic or predictive models, selection of patients for phase II trials, stratification in phase III studies, and identification of patient subgroups for development of novel therapies. Data transparency also helps promote a public image of collaboration and altruism among industry participants. For patient participants, data sharing maximizes their contribution to public health and increases access to information that may be used to develop better treatments. Concerns about data‐sharing efforts include protection of patient privacy and confidentiality. To alleviate these concerns, data sets are deidentified to maintain anonymity. To address industry concerns about protection of intellectual property and competitiveness, we illustrate several models for data sharing with varying levels of access to the data and varying relationships between trial sponsors and data access sponsors.
The Project Data Sphere Initiative.
PDS is an independent initiative of the CEO Roundtable on Cancer Life Sciences Consortium, built to voluntarily share, integrate, and analyze comparator arms of historical cancer clinical trial data sets to advance future cancer research. The aim is to provide a neutral, broad‐access platform for industry and academia to share raw, deidentified data from late‐phase oncology clinical trials using comparator‐arm data sets. These data are likely to be hypothesis generating or hypothesis confirming but, notably, do not take the place of performing a well‐designed trial to address a specific hypothesis. Prospective providers of data to PDS complete and sign a data sharing agreement that includes a description of the data they propose to upload, and then they follow easy instructions on the website for uploading their deidentified data. The SAS Institute has also collaborated with the initiative to provide intrinsic analytic tools accessible within the website itself.
As of October 2014, the PDS website has available data from 14 cancer clinical trials covering 9,000 subjects, with hopes to further expand the database to include more than 25,000 subject accruals within the next year. PDS differentiates itself from other data‐sharing initiatives by its degree of openness, requiring submission of only a brief application with background information of the individual requesting access and agreement to terms of use. Data from several different sponsors may be pooled to develop a comprehensive cohort for analysis. In order to protect patient privacy, data providers in the U.S. are responsible for deidentifying data according to standards set forth by the Privacy Rule of the U.S. Health Insurance Portability and Accountability Act of 1996.
Using Data Sharing to Improve Outcomes in Cancer: The “Prostate Cancer Challenge.”
Control‐arm data of several studies among patients with metastatic castration‐resistant prostate cancer (mCRPC) are currently available through PDS. These data sets have multiple potential uses. The “Prostate Cancer Challenge” will ask the cancer research community to use clinical trial data deposited in the PDS website to address key research questions regarding mCRPC.
General themes that could be explored by the cancer community are described in this article: prognostic models evaluating the influence of pretreatment factors on survival and patient‐reported outcomes; comparative effectiveness research evaluating the efficacy of standard of care therapies, as illustrated in our companion article comparing mitoxantrone plus prednisone with prednisone alone; effects of practice variation in dose, frequency, and duration of therapy; level of patient adherence to elements of trial protocols to inform the design of future clinical trials; and age of subjects, regional differences in health care, and other confounding factors that might affect outcomes.
Potential Limitations and Methodological Challenges.
The number of data sets available and the lack of experimental‐arm data limit the potential scope of research using the current PDS. The number of trials is expected to grow exponentially over the next year and may include multiple cancer settings, such as breast, colorectal, lung, hematologic malignancy, and bone marrow transplantation. Other potential limitations include the retrospective nature of the data analyses performed using PDS and its generalizability, given that clinical trials are often conducted among younger, healthier, and less racially diverse patient populations. Methodological challenges exist when combining individual patient data from multiple clinical trials; however, advancements in statistical methods for secondary database analysis offer many tools for reanalyzing data arising from disparate trials, such as propensity score matching. Despite these concerns, few if any comparable data sets include this level of detail across multiple clinical trials and populations.
Conclusion.
Access to large, late‐phase, cancer‐trial data sets has the potential to transform cancer research by optimizing research efficiency and accelerating progress toward meaningful improvements in cancer care. This type of platform provides opportunities for unique research projects that can examine relatively neglected areas and that can construct models necessitating large amounts of detailed data. The full potential of PDS will be realized only when multiple tumor types and larger numbers of data sets are available through the website.
By providing access to large, late‐phase, cancer‐trial data sets, the Project Data Sphere initiative has the potential to transform cancer research by optimizing research efficiency and accelerating progress toward meaningful improvements in cancer care. This type of platform provides opportunities for unique research projects that can examine relatively neglected areas and that can construct models necessitating large amounts of detailed data.
Abstract
Background
Differential use of endocrine therapy (ET) by race may contribute to breast cancer outcome disparities, but racial differences in ET behaviors are poorly understood.
Methods
Women ...aged 20–74 years with a first primary, stage I–III, hormone receptor–positive (HR+) breast cancer were included. At 2 years postdiagnosis, we assessed nonadherence, defined as not taking ET every day or missing more than two pills in the past 14 days, discontinuation, and a composite measure of underuse, defined as either missing pills or discontinuing completely. Using logistic regression, we evaluated the relationship between race and nonadherence, discontinuation, and overall underuse in unadjusted, clinically adjusted, and socioeconomically adjusted models.
Results
A total of 1280 women were included; 43.2% self-identified as black. Compared to white women, black women more often reported nonadherence (13.7% vs 5.2%) but not discontinuation (10.0% vs 10.7%). Black women also more often reported the following: hot flashes, night sweats, breast sensitivity, and joint pain; believing that their recurrence risk would not change if they stopped ET; forgetting to take ET; and cost-related barriers. In multivariable analysis, black race remained statistically significantly associated with nonadherence after adjusting for clinical characteristics (adjusted odds ratio = 2.72, 95% confidence interval = 1.75 to 4.24) and after adding socioeconomic to clinical characteristics (adjusted odds ratio = 2.44, 95% confidence interval = 1.50 to 3.97) but was not independently associated with discontinuation after adjustment. Low recurrence risk perception and lack of a shared decision making were strongly predictive of ET underuse across races.
Conclusions
Our results highlight important racial differences in ET-adherence behaviors, perceptions of benefits/harms, and shared decision making that may be targeted with culturally tailored interventions.
African American breast cancer patients have lower frequency of hormone receptor-positive (HR+)/human epidermal growth factor receptor 2 (HER2)-negative disease and higher subtype-specific mortality. ...Racial differences in molecular subtype within clinically defined subgroups are not well understood.
Using data and biospecimens from the population-based Carolina Breast Cancer Study (CBCS) Phase 3 (2008-2013), we classified 980 invasive breast cancers using RNA expression-based PAM50 subtype and recurrence (ROR) score that reflects proliferation and tumor size. Molecular subtypes (Luminal A, Luminal B, HER2-enriched, and Basal-like) and ROR scores (high vs low/medium) were compared by race (blacks vs whites) and age (≤50 years vs > 50 years) using chi-square tests and analysis of variance tests.
Black women of all ages had a statistically significantly lower frequency of Luminal A breast cancer (25.4% and 33.6% in blacks vs 42.8% and 52.1% in whites; younger and older, respectively). All other subtype frequencies were higher in black women (case-only odds ratio OR = 3.11, 95% confidence interval CI = 2.22 to 4.37, for Basal-like; OR = 1.45, 95% CI = 1.02 to 2.06, for Luminal B; OR = 2.04, 95% CI = 1.33 to 3.13, for HER2-enriched). Among clinically HR+/HER2- cases, Luminal A subtype was less common and ROR scores were statistically significantly higher among black women.
Multigene assays highlight racial disparities in tumor subtype distribution that persist even in clinically defined subgroups. Differences in tumor biology (eg, HER2-enriched status) may be targetable to reduce disparities among clinically ER+/HER2- cases.
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