Differences in characteristics of US hematopoietic stem cell transplantation centers by proportion of racial or ethnic minorities

Disparity in hematological malignancies: From patients to health care professionals

In the recent few decades, outcomes in patients diagnosed with hematological malignancies have been steadily improving. However, the improved prognosis does not distribute equally among patients from different backgrounds. Besides cancer biology, demographic and geographic disparities have been found to impact overall survival significantly. Specifically, patients from underrepresented minorities including Black and Hispanics, and those with uninsured status, having low socioeconomic status, or from rural areas have had worse outcomes historically, which is uniformly true across all major subtypes of hematological malignancies. Similar discrepancy is also seen in the health care professional field, where a gender gap and a disproportionally low representation of health care providers from underrepresented minorities have been long existing. Thus, a comprehensive strategy to mitigate disparity in the health care system is needed to achieve equity in health care.

Racial disparities in hematopoietic stem cell transplant: a systematic review of the literature

Background

Hematopoietic stem cell transplant (HSCT) is an expensive and complex treatment regimen that can be curative in many diseases of the bone marrow, including malignant and non-malignant conditions. The introduction of the Affordable Care Act increased access to potential candidates and removed or reduced many barriers previously identified in the literature, however, racial disparities continue to persist. As HSCT expands its utilization and indications, there is a continued need to understand the multifactorial barriers which lead to inequalities in transplant referral, utilization, and survival. The objective of this systematic review is to summarize these racial disparities, expand the current understanding of the literature, and determine whether the increases in insurance status from Medicaid expansion have played a role in HSCT utilization and survival rates by race.

Methods

We explored studies based on retrospective reviews, literature reviews, and focus groups with the key-terms of 'race', 'hematopoietic stem cell transplant', and 'disparities'. The included studies were extracted from Cochrane and Medline databases. After screening for relevancy to research aims and objectives, 10 articles were utilized for background information and discussion, while 30 articles were categorized into main groups of outcomes, chiefly, (I) access/referral to transplant and (II) survival.

Results

Eight of the eleven retrospective reviews found substantial variation in access to HSCT by ethnic minorities (Black, Hispanic, or Asian) when compared to their Caucasian counterparts. Thirteen of the fourteen publications found racial disparities in either overall survival, progression free survival, treatment related mortality, relapse, or combinations of these outcomes. The majority of the studies evaluated African American patients with six of eight studies showing significantly elevated mortality compared to Caucasian patients.

Discussion

Substantial variation exists in access to HSCT, particularly in black patients. Having less generous insurance coverage was previously hypothesized to reduce the likelihood of HSCT utilization. Studies performed after full implementation of the Affordable Care Act continue to show poorer survival among ethnic minorities, particularly black patients, despite this increased coverage. Perceived racial bias and health-related stigma, as well as physician decisions and delay in referral process are likely contributing factors.

Parental limited English proficiency in pediatric stem cell transplantation: Clinical impact and health care utilization

BACKGROUND

Limited English proficiency (LEP) is associated with adverse clinical outcomes. The clinical impact of LEP in hematopoietic stem cell transplant (HSCT) has not been studied. The objectives of this study were to compare HSCT outcomes and health care utilization of Hispanic pediatric patients with and without parental LEP.

METHODS

We conducted a retrospective review of Hispanic/Latino pediatric patients receiving HSCT at a single institution. Families were identified as LEP or English proficient (EP) based on clinicians' notes, social work documentation, or the signature of a Spanish interpreter on treatment consents.

RESULTS

A total of 83 Hispanic/Latino patients were identified with 53 (65.1%) having parental LEP. More patients in the LEP group had a documented financial burden at pretransplant psychosocial evaluation (72.2% vs. 41.4%, p = .009). LEP patients were more likely to have health insurance coverage through government-sponsored Medicaid (76.9% vs. 27.6%, p < .001). LEP patients were hospitalized on average 13 days longer than EP patients, and LEP patients were more likely to have pretransplant cytomegalovirus (CMV) reactivity (67.3%) than EP patients (p = .001). Overall survival was lower in LEP than EP, but was not statistically significant (p = .193). Multivariable Cox modeling suggested a potentially higher risk of death in LEP versus EP (hazard ratio = 1.56, 95% CI: 0.38, 6.23).

CONCLUSIONS

Parental LEP in HSCT is associated with prolonged hospitalization and pretransplant CMV reactivity. These factors are associated with posttransplant complications and death. Our results suggest parental LEP is a risk factor for poor HSCT outcomes. Further study is warranted in a larger cohort.

Milestones of Hematopoietic Stem Cell Transplantation - From First Human Studies to Current Developments

Since the early beginnings, in the 1950s, hematopoietic stem cell transplantation (HSCT) has become an established curative treatment for an increasing number of patients with life-threatening hematological, oncological, hereditary, and immunological diseases. This has become possible due to worldwide efforts of preclinical and clinical research focusing on issues of transplant immunology, reduction of transplant-associated morbidity, and mortality and efficient malignant disease eradication. The latter has been accomplished by potent graft-versus-leukemia (GvL) effector cells contained in the stem cell graft. Exciting insights into the genetics of the human leukocyte antigen (HLA) system allowed improved donor selection, including HLA-identical related and unrelated donors. Besides bone marrow, other stem cell sources like granulocyte-colony stimulating-mobilized peripheral blood stem cells and cord blood stem cells have been established in clinical routine. Use of reduced-intensity or non-myeloablative conditioning regimens has been associated with a marked reduction of non-hematological toxicities and eventually, non-relapse mortality allowing older patients and individuals with comorbidities to undergo allogeneic HSCT and to benefit from GvL or antitumor effects. Whereas in the early years, malignant disease eradication by high-dose chemotherapy or radiotherapy was the ultimate goal; nowadays, allogeneic HSCT has been recognized as cellular immunotherapy relying prominently on immune mechanisms and to a lesser extent on non-specific direct cellular toxicity. This chapter will summarize the key milestones of HSCT and introduce current developments.

Reduced intensity haplo plus single cord transplant compared to double cord transplant: improved engraftment and graft-versus-host disease-free, relapse-free survival

Umbilical cord blood stem cell transplants are commonly used in adults lacking HLA-identical donors. Delays in hematopoietic recovery contribute to mortality and morbidity. To hasten recovery, we used co-infusion of progenitor cells from a partially matched related donor and from an umbilical cord blood graft (haplo-cord transplant). Here we compared the outcomes of haplo-cord and double-cord transplants. A total of 97 adults underwent reduced intensity conditioning followed by haplo-cord transplant and 193 patients received reduced intensity conditioning followed by double umbilical cord blood transplantation. Patients in the haplo-cord group were more often from minority groups and had more advanced malignancy. Haplo-cord recipients received fludarabine-melphalan-anti-thymocyte globulin. Double umbilical cord blood recipients received fludarabine-cyclophosphamide and low-dose total body irradiation. In a multivariate analysis, haplo-cord had faster neutrophil (HR=1.42, P=0.007) and platelet (HR=2.54, P<0.0001) recovery, lower risk of grade II-IV acute graft-versus-host disease (HR=0.26, P<0.0001) and chronic graft-versus-host disease (HR=0.06, P<0.0001). Haplo-cord was associated with decreased risk of relapse (HR 0.48, P=0.001). Graft-versus-host disease-free, relapse-free survival was superior with haplo-cord (HR 0.63, P=0.002) but not overall survival (HR=0.97, P=0.85). Haplo-cord transplantation using fludarabine-melphalan-thymoglobulin conditioning hastens hematopoietic recovery with a lower risk of relapse relative to double umbilical cord blood transplantation using the commonly used fludarabine-cyclophosphamide-low-dose total body irradiation conditioning. Graft-versus-host disease-free and relapse-free survival is significantly improved. Haplo-cord is a readily available graft source that improves outcomes and access to transplant for those lacking HLA-matched donors. Trials registered at clinicaltrials.gov identifiers 00943800 and 01810588.

Impact of race and ethnicity on outcomes and health care utilization after allogeneic hematopoietic cell transplantation

Disparities in outcomes after hematopoietic cell transplant (HCT) are reported mostly by registry studies. We examined the association of self-reported race and ethnicity with outcomes and health care utilization after allogeneic HCT in a single center study. Clinical and socioeconomic data of 296 adult patients who underwent allogeneic HCT from November 2003 to October 2012 were analyzed. Survival was compared between non-Hispanic Whites (NHW) and minority patients using Cox proportional hazards regression. Some 73% of patients were NHW and 27% were racial/ethnic minority patients. More minority patients were younger and had lower socioeconomic status. Both unadjusted and adjusted overall and progression-free survival were comparable between the two groups. High risk disease, poor performance score and Medicare/Tricare were significant predictors of mortality. Health care utilization was comparable between the two groups. Homogeneity of medical care for allogeneic HCT may help overcome racial/ethnic disparities, but not those due to patients' primary insurance.

Factors associated with self-reported physical and mental health after hematopoietic cell transplantation

Hematopoietic cell transplantation (HCT) is an intensive treatment for hematologic malignancies that has the potential to cure disease or prolong life, but also to impair quality of life for survivors. Earlier studies have suggested that various factors are associated with physical and mental health after HCT. In this study, we evaluated demographic and clinical factors before and after HCT and selected psychosocial factors after HCT, exploring their association with self-reported physical and mental health. We studied a cohort of 662 survivors at a median of 6.6 years after HCT. Pre-HCT demographic and clinical factors accounted for only a small amount of the variance in physical and mental health post-HCT (3% and 1%, respectively). Adding post-HCT clinical variables to the pre-HCT factors accounted for 32% and 7% of physical and mental outcomes, respectively. When both clinical and psychosocial factors were considered, better physical health post-HCT was associated with younger age, race other than white, higher current family income, currently working or being a student, less severe transplantation experience (ie, not experiencing graft-versus-host disease), fewer current comorbidities, higher Karnofsky status, less social constraint, less social support, and less trait anxiety. This multivariate model accounted for 36% of the variance in physical health, with the psychosocial variables contributing very little. When both clinical and psychosocial factors were considered, better mental health after HCT was associated with more severe transplantation experience, less social constraint, greater spiritual well being, and less trait anxiety. This multivariate model accounted for 56% of the variance in mental health, with the psychosocial factors accounting for most of the variance. These data suggest that clinical factors are explanatory for much of the post-HCT physical health reported by HCT survivors, but very little of self-perceived mental health. These observations provide insight into the identification of factors that can allow recognition of at-risk patients, as well as factors amenable to intervention.

NCI First International Workshop on the Biology, Prevention, and Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation: report from the Committee on the Epidemiology and Natural History of Relapse following Allogeneic Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is increasingly being used for treatment of hematologic malignancies, and the immunologic graft-versus-tumor effect (GVT) provides its therapeutic effectiveness. Disease relapse remains a cause of treatment failure in a significant proportion of patients undergoing alloHSCT without improvements over the last 2-3 decades. We summarize here current data and outline future research regarding the epidemiology, risk factors, and outcomes of relapse after alloHSCT. Although some factors (eg, disease status at alloHSCT or graft-versus-host disease [GVHD] effects) are common, other disease-specific factors may be unique. The impact of reduced-intensity regimens on relapse and survival still need to be assessed using contemporary supportive care and comparable patient populations. The outcome of patients relapsing after an alloHSCT generally remains poor even though interventions including donor leukocyte infusions can benefit some patients. Trials examining targeted therapies along with improved safety of alloHSCT may result in improved outcomes, yet selection bias necessitates prospective assessment to gauge the real contribution of any new therapies. Ongoing chronic GVHD (cGVHD) or other residual post-alloHSCT morbidities may limit the applicability of new therapies. Developing strategies to promptly identify patients as alloHSCT candidates, while malignancy is in a more treatable stage, could decrease relapses rates after alloHSCT. Better understanding and monitoring of minimal residual disease posttransplant could lead to novel preemptive treatments of relapse. Analyses of larger cohorts through multicenter collaborations or registries remain essential to probe questions not amenable to single center or prospective studies. Studies need to provide data with detail on disease status, prior treatments, biologic markers, and posttransplant events. Stringent statistical methods to study relapse remain an important area of research. The opportunities for improvement in prevention and management of post-alloHSCT relapse are apparent, but clinical discipline in their careful study remains important.

Methodological and logistical considerations to study design and data collection in racial/ethnic minority populations evaluating outcome disparity in hematopoietic cell transplantation

Outcome disparity associated with race or ethnicity in the United States has been observed in hematopoietic cell transplantation (HCT). The underlying reasons for such disparity are not known. In the United States, an optimal study of health care disparity by race or ethnicity involves consideration of both biologic and psychosocial determinants, which requires an adequately powered, prospective cohort study design. To better characterize the nature and quantify the magnitude of the many impediments relevant to conducting a successful prospective study involving racial or ethnic minorities in HCT, we conducted a feasibility study to help guide planning of a larger scale outcome and disparity study in HCT. The primary questions to be addressed in the study were: (1) can we establish a racially or ethnically diverse patient sample that will respond to a survey focused on sociodemographic, economic, health insurance, cultural, spiritual, and religious well-being, and social support information? (2) What is the retention rate in the study over time? (3) What is the quality of the data collected from the patients over time? The challenges we faced in conducting this multicenter feasibility study are summarized in this report. Despite the difficulty in conducting disparity studies in racial and ethnic minorities, such studies are essential to ensure that people of all ethnic and racial backgrounds have the best chance possible of benefiting from HCT.

What are the most important donor and recipient factors affecting the outcome of related and unrelated allogeneic transplantation?

Several recipient and donor risk factors affect outcome after transplantation with allogeneic hematopoietic stem cells. The most important recipient risk factors are patient age, comorbidity, performance status, cytomegalovirus (CMV) status, and disease considerations, such as diagnosis, stage, and cytogenetic risk. Prior chemotherapy regimens, patient race, and IL10 promoter polymorphism also appear to have some impact, but to a lesser extent. The most important donor factor is the level of HLA mismatch. Donor gender, relation, age, and KIR genotype also affect outcome. Donor CMV serology, parity, and race do not appear to affect outcome. These factors must all be considered in relation to one another when selecting whether to recommend patients for transplant.