Race and socioeconomic status influence outcomes of unrelated donor hematopoietic cell transplantation

Electronic medical records and quality of cancer care

The implementation of electronic medical records (EMR) systems was mandated by the U.S. federal government in large part due to research indicating that difficulty accessing clinical data was one of the most common causes of preventable deaths. Several assumptions were implicit in this mandate, including the assumption that the implementation of EMR would indeed improve clinicians' access to clinical data, that implementation of EMR would pose little to no risk to patients, and that the clinical benefit of improved access to clinical data would outweigh any risks that might arise. As detailed in this review, both formal research and extensive experiential observation have called all three assumptions into question. Specifically, as detailed below, there is clear evidence that EMR systems are associated with multiple specific risks to patients, whereas few, if any, scientifically rigorous outcomes-based studies have demonstrated that the potential benefits of EMR outweigh the known risks. In addition, there is currently little to no scientifically rigorous evidence that EMR systems constitute a cost-effective methodology for improving patient outcomes.

Effect of race on outcomes after allogeneic hematopoietic cell transplantation for severe aplastic anemia

We compared outcomes after hematopoietic cell transplantation in patients of African American (n = 84) and Caucasian (n = 215) descent with severe aplastic anemia. African Americans and Caucasians were matched for age, donor-recipient human leukocyte antigen match, graft type, and transplantation year. The median follow-up of surviving patients was 5 years. In multivariate analysis, overall mortality risks were higher for African Americans compared to Caucasians (relative risk 1.73, P = 0.01). The 5-year probabilities of overall survival adjusted for interval from diagnosis to transplantation, and performance score was 58% for African Americans and 73% for Caucasians. The day-100 cumulative incidence of grade III-IV, but not grade II-IV acute graft-versus-host disease (GVHD), was higher in African Americans compared to Caucasians (29% vs. 13%, P = 0.006). Although the 5-year cumulative incidence of chronic GVHD was not significantly different between the racial groups, African Americans were more likely to have extensive chronic GVHD compared to Caucasians (72% vs. 49%, P = 0.06). Survival differences between Caucasians and African Americans can be attributed to multiple factors. Our data suggest that some of the observed survival differences between Caucasians and African Americans may be explained by higher rates of acute GVHD and severity of chronic GVHD.

Psychosocial factors and hematopoietic stem cell transplantation: potential biobehavioral pathways

While psychosocial factors are known to affect cancer progression via biobehavioral pathways in many patient populations, these relationships remain largely unexplored in hematopoietic stem cell transplant (HCT) patients. The purpose of this paper is to critically review the literature regarding psychosocial and endocrine/immune aspects of HCT, with an emphasis on exploring pathways that may mediate the associations between psychosocial factors and disease outcomes. These include the roles of catecholamines, glucocorticoids, inflammation, vascular endothelial growth factor (VEGF), immune reconstitution and infectious susceptibility, as well as the new opportunities available in genomics research. We also discuss the implications for potential immunomodulating psychosocial interventions. Elucidating the biological pathways that account for the associations between psychosocial factors and clinical course could ultimately lead to improved outcomes for this psychologically and immunologically vulnerable population.

Risk assessment before allogeneic hematopoietic cell transplantation for older adults with acute myeloid leukemia

Acute myeloid leukemia (AML) most commonly affects patients older than 60 years. Outcomes of treatment of older AML patients have been poor. The advent of reduced-intensity conditioning (RIC) regimens made allogeneic hematopoietic cell transplantation (HCT) an available treatment option with curative intent for older AML patients. Because older patients are often excluded from clinical trials, little is known about the stratification of their risks before allogeneic HCT. While recent studies of RIC and allogeneic HCT have shown little impact of age on outcomes, other variables such as the recipient health status and the AML disease status and chromosomal aberrations have proven to be of prognostic significance. Here, the authors review recent studies of allogeneic HCT for older patients with AML with detailed evaluation of risk factors for relapse as well as non-relapse mortality. The authors have integrated the currently available information on transplant risks into a five-category risk-benefit system that could aid in the decision-making in this patient population.

Unrelated umbilical cord blood transplant for adult acute lymphoblastic leukemia in first and second complete remission: a comparison with allografts from adult unrelated donors

Allogeneic hematopoietic cell transplantation has an established role in the treatment of adults with acute lymphoblastic leukemia whose survival when recipients of grafts from adult unrelated donors approaches that of recipients of grafts from sibling donors. Our aim was to determine the role of mismatched unrelated cord blood grafts in transplantation for 802 adults with acute lymphoblastic leukemia in first or second complete remission. Using Cox regression we compared outcomes after 116 mismatched single or double cord blood transplants, 546 peripheral blood progenitor cell transplants and 140 bone marrow transplants. The characteristics of the recipients and their diseases were similar except cord blood recipients were younger, more likely to be non-Caucasians and more likely to have a low white blood cell count at diagnosis. There were differences in donor-recipient human leukocyte antigen-match depending on the source of the graft. Most adult donor transplants were matched at the allele-level considering human leukocyte antigens-A, -B, -C and -DRB1. In contrast, most cord blood transplants were mismatched and considered antigen-level matching; 57% were mismatched at two loci and 29% at one locus whereas only 29% of adult donor transplants were mismatched at one locus and none at two loci. There were no differences in the 3-year probabilities of survival between recipients of cord blood (44%), matched adult donor (44%) and mismatched adult donor (43%) transplants. Cord blood transplants engrafted slower and were associated with less grade 2-4 acute but similar chronic graft-versus-host disease, relapse, and transplant-related mortality. The survival of cord blood graft recipients was similar to that of recipients of matched or mismatched unrelated adult donor grafts and so cord blood should be considered a valid alternative source of stem cells for adults with acute lymphoblastic leukemia in the absence of a matched unrelated adult donor.

Significance of ethnicity in the risk of acute graft-versus-host disease and leukemia relapse after unrelated donor hematopoietic stem cell transplantation

The significance of patient and donor ethnicity on risk of acute graft-versus-host disease (GVHD) and disease relapse after unrelated donor hematopoietic cell transplantation (HCT) is not known. A total of 4335 patient-donor pairs from the International Histocompatibility Working Group in HCT met the following 3 criteria: (1) HLA-A, -B, -C, -DRB1, and -DQB1 allele matched donor, (2) diagnosis of leukemia, and (3) non-T cell depleted GVHD prophylaxis. Posttransplantation risks of acute GVHD and leukemia relapse were defined in Asian/Pacific Islander, white, African American, Hispanic, and Native American patients that underwent transplantation from donors with the same self-described background. Asian patients had a significantly lower incidence of acute GVHD (Japanese patients: 40.0% grades II to IV and 15.3% grades III to IV; non-Japanese Asian patients: 42.1% grades II to IV and 15.7% grades III to IV) compared with white patients (56.5% grades II to IV and 22.6% grades III to IV) (P < .001). The hazard ratio of acute GVHD for white patients was significantly higher than for Japanese patients. Unexpectedly, the hazard ratio of leukemia relapse in white patients with early disease status was also significantly higher than that in Japanese patients. These results provide a platform for future investigation into the genetic factors for unrelated donor HCT and clinical implications of diverse ethnic background.

Importance of donor ethnicity/race matching in unrelated adult and cord blood allogeneic hematopoietic cell transplant

Donor race matching (both recipient and donor belonging to the same race) might be a factor in outcomes of donor allogeneic hematopoietic cell transplant (alloHCT). A total of 858 patients who underwent umbilical cord blood (UCB) (475 patients: 202 double UCB and 273 single UCB) or unrelated donor (URD) (383 patients) alloHCT between January 1995 and December 2010 were studied. Most patients were Caucasian (87%), followed by Asians (4%), African Americans (3%), Hispanics (3%), mixed race (3%) and American Indians (< 1%). Caucasians constituted 88% of the donor grafts; Caucasians were the most common race of the donor grafts among all races except for Asians. As a result, Caucasians were much more likely to have a race-matched donor than ethnic minorities (91% vs. 33%, p < 0.01). Donor race matching did not affect non-relapse mortality, relapse, acute or chronic graft-versus-host disease or overall survival. Acknowledging the limitations of this study (mainly, self-reported race information and small number of ethnic minorities), at present there are no data supporting that donor race should be considered a factor in donor selection.

Mapping MHC haplotype effects in unrelated donor hematopoietic cell transplantation

Life-threatening risks associated with HLA-mismatched unrelated donor hematopoietic cell transplantation limit its general application for the treatment of blood diseases. The increased risks might be explained by undetected genetic variation within the highly polymorphic major histocompatibility complex (MHC) region. We retrospectively assessed each of 1108 MHC region single nucleotide polymorphisms (SNPs) in 2628 patients and their HLA-mismatched unrelated donors to determine whether SNPs are associated with the risk of mortality, disease-free survival, transplant-related mortality, relapse, and acute and chronic graft-versus-host disease (GVHD). Multivariate analysis adjusted for HLA mismatching and nongenetic variables associated with each clinical end point. Twelve SNPs were identified as transplantation determinants. SNP-associated risks were conferred by either patient or donor SNP genotype or by patient-donor SNP mismatching. Risks after transplantation increased with increasing numbers of unfavorable SNPs. SNPs that influenced acute GVHD were independent of those that affected risk of chronic GVHD and relapse. HLA haplotypes differed with respect to haplotype content of (un)favorable SNPs. Outcome after HLA-mismatched unrelated donor transplantation is influenced by MHC region variation that is undetected with conventional HLA typing. Knowledge of the SNP content of HLA haplotypes provides a means to estimate risks prior to transplantation and to lower complications through judicious selection of donors with favorable MHC genetics.

Tertiary center referral patterns for patients with myelodysplastic syndrome are indicative of age and race disparities: a single-institution experience

Little is known about disparities in myelodysplastic syndromes (MDS). We performed a retrospective chart review of patients with MDS (n = 252) evaluated at the University of Maryland Greenebaum Cancer Center between 2000 and 2010. The median age at diagnosis was 65 years, which was lower than the median age of 76 years for patients with MDS in the Surveillance, Epidemiology and End Results database. Black males were younger than white males (62 vs. 68 years; p = 0.03) and had longer time to referral (9 vs. 1.5 months; p = 0.03), but black and white females did not differ in age or in time to referral. A difference in World Health Organization subtype classification was noted in black and white patients at diagnosis, but not at referral. There was no difference between all other pretreatment characteristics, treatment and survival by race. Our data suggest barriers to tertiary care referral for older patients and for black males.

MHC-resident variation affects risks after unrelated donor hematopoietic cell transplantation

Blood malignancies can be cured with hematopoietic cell transplantation from human leukocyte antigen (HLA)-matched unrelated donors; however, acute graft-versus-host disease (GVHD) affects up to 80% of patients and contributes to increased mortality. To test the hypothesis that undetected patient-donor differences for non-HLA genetic variation within the major histocompatibility complex (MHC) could confer risks after HLA-matched transplantation, we conducted a discovery-validation study of 4205 transplants for 1120 MHC region single-nucleotide polymorphisms (SNPs). Two SNPs were identified as markers for disease-free survival and acute GVHD. Among patients with two or more HLA-matched unrelated donors identified on their search, SNP genotyping of patients and their potential donors demonstrated that most patients have a choice of SNP-matched donors. In conclusion, the success of HLA-matched unrelated donor hematopoietic cell transplantation depends on non-HLA MHC region genetic variation. Prospective SNP screening and matching provides an approach for lowering risks to patients.

Human leukocyte antigen profiles of latin american populations: differential admixture and its potential impact on hematopoietic stem cell transplantation

The outcome of hematopoietic stem cell transplantation (HSCT) is shaped by both clinical and genetic factors that determine its success. Genetic factors including human leukocyte antigen (HLA) and non-HLA genetic variants are believed to influence the risk of potentially fatal complications after the transplant. Moreover, ethnicity has been proposed as a factor modifying the risk of graft-versus-host disease. The populations of Latin America are a complex array of different admixture processes with varying degrees of ancestral population proportions that came in different migration waves. This complexity makes the study of genetic risks in this region complicated unless the extent of this variation is thoroughly characterized. In this study we compared the HLA-A and HLA-B allele group profiles for 31 Latin American populations and 61 ancestral populations from Iberia, Italy, Sub-Saharan Africa, and America. Results from population genetics comparisons show a wide variation in the HLA profiles from the Latin American populations that correlate with different admixture proportions. Populations in Latin America seem to be organized in at least three groups with (1) strong Amerindian admixture, (2) strong Caucasian component, and (3) a Caucasian-African gradient. These results imply that genetic risk assessment for HSCT in Latin America has to be adapted for different population subgroups rather than as a pan-Hispanic/Latino analysis.

Racial disparities in hematopoietic cell transplantation in the United States

Hematopoietic cell transplantation (HCT) is a highly specialized, expensive and resource-intense medical procedure that can be associated with racial disparities. We review the prevailing literature on racial disparities in HCT in the United States and describe areas for future research and interventions. We discuss the complexity of interpreting race as a biological and social determinant of disease in biomedical research, especially as it relates to HCT. In the United States, race is often a surrogate for socioeconomic, education and health insurance status. We also discuss some of the nuances to consider while reviewing the literature on racial disparities. Disparities by race exist in three areas related to HCT: donor availability, access to HCT and outcomes of HCT. African-Americans/Blacks have a lower likelihood of finding an unrelated donor. Race and ethnicity definitions are country-specific and reconciling race data can represent significant challenges to unrelated donor registries worldwide. African-Americans/Blacks do not have the same access to autologous and allogeneic HCT as Whites. Racial disparities in outcomes of HCT are more prevalent among allogeneic HCT than autologous HCT recipients. More research is required to understand the biological, social, cultural, medical and financial aspects of race that may influence access to HCT and survival after transplantation. Better understanding of racial disparities will minimize inequities, inform health policy, guide development of interventions targeted to eliminate disparities and ensure equitable access to HCT for all populations.

Race/ethnicity affects the probability of finding an HLA-A, -B, -C and -DRB1 allele-matched unrelated donor and likelihood of subsequent transplant utilization

Factors relevant to finding a suitable unrelated donor and barriers to effective transplant utilization are incompletely understood. Among a consecutive series of unrelated searches (n=531), an 8/8 HLA-A, -B, -C and -DRB1-matched unrelated donor was available for 289 (54%) patients, 7/8 for 159 (30%) and no donor for 83 (16%). Patients of Caucasian race (P<0.0001) were more likely to find a donor. Younger age (P=0.01), Caucasian race (P=0.03), lower CIBMTR (Center for International Blood and Marrow Transplantation Research) risk (P=0.005), and 8/8 HLA matching (P=0.005) were associated with higher odds of reaching hematopoietic cell transplantation (HCT). In a univariate analysis of OS, finding a donor was associated with hazard ratio (HR) of 0.85 (95% CI 0.63-1.2), P=0.31. Karnofsky performance status (KPS) accounted for interaction between having a donor and survival. Patients with KPS 90-100 and a donor had significantly reduced hazard for death (HR 0.59, 95% CI 0.38-0.90, P=0.02). These data provide estimates of the probability to find an unrelated donor in the era of high-resolution HLA typing, and identify potentially modifiable barriers to reaching HCT. Further efforts are needed to enhance effective donor identification and transplant utilization, particularly in non-Caucasian ethnic groups.

Racial disparities in Hodgkin's lymphoma: a comprehensive population-based analysis

BACKGROUND

Racial disparity has been investigated in a number of cancers; however, there remains a comparative paucity of data in Hodgkin's lymphoma (HL).

PATIENTS AND METHODS

We examined time-, age-, and gender-specific incidence, disease characteristics, and survival across and within races for adolescent/adult HL (age 10-79 years) diagnosed during 1992-2007 in the SEER 13 registries.

RESULTS

A total of 15 662 HL cases were identified [11,211 non-Hispanic whites, 2067 Hispanics, 1662 blacks, and 722 Asian/Pacific Islanders (A/PI)]. Similar to whites, A/PIs had bimodal age-specific incidence, while blacks and Hispanics did not. Further, HL was significantly more common in Hispanics versus whites age>65 years (7.0/1×10(6) versus 4.5/1×10(6), respectively, P<0.01). By place of birth, US-born Hispanics and A/PIs age 20-39 years had higher incidence of HL versus their foreign-born counterparts (P<0.05), however, rates converged age>40 years. Interestingly, from 1992-1997 to 2003-2007, A/PI incidence rates increased >50% (P<0.001). Moreover, this increase was restricted to US-born A/PI. We also identified a number of disease-related differences based on race. Finally, 5-, 10-, and 15-year overall survival rates were inferior for blacks and Hispanics compared with whites (P<0.005 and P<0.001, respectively) and A/PI (P<0.018 and P<0.001, respectively). These differences persisted on multivariate analysis.

CONCLUSION

Collectively, we identified multiple racial disparities, including survival, in adolescent/adult HL.

Practice variation in physician referral for allogeneic hematopoietic cell transplantation

Hematological malignancy patients not referred by their primary hematologist/medical oncologist suffer disparate access to allogeneic hematopoietic cell transplantation (HCT). However, investigation into physician, system and patient factors relevant to this decision making is lacking. We surveyed a national randomized sample of practicing hematologists/medical oncologists identified through the AMA (American Medical Association) masterfile. A modified Dillman approach was utilized to encourage survey response. From 1200 surveyed, a total of 113 physicians responded. In all, 68% were male, 62% identified as White/non-Hispanic, 79% practiced in non-academic settings and 80% reported spending 75-100% of their professional effort in clinical care. Using clinical vignettes, we detected significantly increased odds for HCT non-referral according to age (age 60 vs 30, odds ratio (OR) 8.3, 95% confidence interval (CI): 5.9-11.7, P<0.0001), insurance coverage (no coverage vs coverage, OR 6.9, 95% CI: 5.2-9.1, P<0.0001) and race (African-American vs Caucasian, OR 2.4, 95% CI: 1.9-2.9, P<0.0001). Physician (perception of HCT risks), system (insurance coverage) and patient (age, social support and co-morbid illness) factors were strongly endorsed by respondents as important determinants of their HCT referral practices. These data speak to important factors relevant to HCT referral practices, and highlight several opportunities for education and intervention to reduce current disparities.

Relationship of race/ethnicity and survival after single umbilical cord blood transplantation for adults and children with leukemia and myelodysplastic syndromes

The relationship of race/ethnicity with outcomes of umbilical cord blood transplantation (UCBT) is not well known. We analyzed the association between race/ethnicity and outcomes of unrelated single UCBT for leukemia and myelodysplastic syndromes. Our retrospective cohort study consisted of 885 adults and children (612 whites, 145 blacks, and 128 Hispanics) who received unrelated single UCBT for leukemia and myelodysplastic syndromes between 1995 and 2006 and were reported to the Center for International Blood and Marrow Transplant Research. A 5-6/6 HLA-matched unit with a total nucleated cell count infused of ≥2.5 × 10(7)/kg was given to 40% white and 42% Hispanic, but only 21% black patients. Overall survival at 2 years was 44% for whites, 34% for blacks, and 46% for Hispanics (P = .008). In multivariate analysis adjusting for patient, disease, and treatment factors (including HLA match and cell dose), blacks had inferior overall survival (relative risk of death, 1.31; P = .02), whereas overall survival of Hispanics was similar (relative risk, 1.03; P = .81) to that of whites. For all patients, younger age, early-stage disease, use of units with higher cell dose, and performance status ≥80 were independent predictors of improved survival. Black patients and white patients infused with well-matched cords had comparable survival; similarly, black and white patients receiving units with adequate cell dose had similar survival. These results suggest that blacks have inferior survival to whites after single UCBT, but outcomes are improved when units with a higher cell dose are used.

Cancer disparities in the context of Medicaid insurance: a comparison of survival for acute myeloid leukemia and Hodgkin's lymphoma by Medicaid enrollment

BACKGROUND

Because poverty is difficult to measure, its association with outcomes for serious illnesses such as hematologic cancers remains largely uncharacterized. Using Medicaid enrollment as a proxy for poverty, we aimed to assess potential disparities in survival after a diagnosis of acute myeloid leukemia (AML) or Hodgkin's lymphoma (HL) in a nonelderly population.

METHODS

We used records from the New York (NY) and California (CA) state cancer registries linked to Medicaid enrollment records for these states to identify Medicaid enrolled and nonenrolled patients aged 21-64 years with incident diagnoses of AML or HL in 2002-2006. We compared overall survival for the two groups using Kaplan-Meier curves and Cox proportional hazards analyses adjusted for sociodemographic and clinical factors.

RESULTS

For HL, the adjusted risk for death for Medicaid enrolled compared with nonenrolled patients was 1.98 (95% confidence interval [CI], 1.47-2.68) in NY and 1.89 (95% CI, 1.43-2.49) in CA. In contrast, for AML, Medicaid enrollment had no effect on survival (adjusted hazard ratio, 1.00; 95% CI, 0.84-1.19 in NY and hazard ratio, 1.02; 95% CI, 0.89-1.16 in CA). These results persisted despite adjusting for race/ethnicity and other factors.

CONCLUSIONS

Poverty does not affect survival for AML patients but does appear to be associated with survival for HL patients, who, in contrast to AML patients, require complex outpatient treatment. Challenges for the poor in adhering to treatment regimens for HL could explain this disparity and merit further study.

Who is fit for allogeneic transplantation?

The use of allogeneic hematopoietic cell transplantation (HCT) has expanded progressively, facilitated by the increasing availability of unrelated donors and cord blood, and the inclusion of older patients as transplantation candidates. Indications remain diagnosis-dependent. As novel nontransplantation modalities have been developed concurrently, many patients come to HCT only when no longer responding to such therapy. However, patients with refractory or advanced disease frequently relapse after HCT, even with high-dose conditioning, and more so with reduced-intensity regimens as used for patients of older age or with comorbid conditions. Thus, patients with high-risk malignancies who have substantial comorbidities or are of advanced age are at high risk of both relapse and nonrelapse mortality and should probably not be transplanted. Being in remission or at least having shown responsiveness to pre-HCT therapy is generally associated with increased transplantation success. In addition, to handle the stress associated with HCT, patients need a good social support system and a secure financial net. They must be well informed, not only about the transplantation process, but also about expected or potential post-HCT events, including graft-versus-host disease and delayed effects that may become manifest only years after HCT.

An eight-year snapshot of geospatial cancer research (2002-2009): clinico-epidemiological and methodological findings and trends

Geographic information systems (GIS) offer a very rich toolbox of methods and technologies, and powerful research tools that extend far beyond the mere production of maps, making it possible to cross-link and study the complex interaction of disease data and factors originating from a wide range of disparate sources. Despite their potential indispensable role in cancer prevention and control programmes, GIS are underrepresented in specialised oncology literature. The latter has provided an impetus for the current review. The review provides an eight-year snapshot of geospatial cancer research in peer-reviewed literature (2002-2009), presenting the clinico-epidemiological and methodological findings and trends in the covered corpus (93 papers). The authors concluded that understanding the relationship between location and cancer/cancer care services can play a crucial role in disease control and prevention, and in better service planning, and appropriate resource utilisation. Nevertheless, there are still barriers that hinder the wide-scale adoption of GIS and related technologies in everyday oncology practice.