Racial and ethnic associations with comprehensive cancer center access and clinical trial enrollment for acute leukemia.

BACKGROUND: Clinical trial participation at Comprehensive Cancer Centers (CCC) is inequitable for minoritized racial and ethnic groups with acute leukemia. CCCs care for a high proportion of adults with acute leukemia. It is unclear if participation inequities are due to CCC access, post-access enrollment, or both. METHODS: We conducted a retrospective cohort study of adults with acute leukemia (2010-2019) residing within Massachusetts, the designated catchment area of the Dana-Farber/Harvard Cancer Center (DF/HCC). Individuals were categorized as non-Hispanic Asian (NHA), Black (NHB), White (NHW), Hispanic White (HW), or Other. Decomposition analyses assessed covariate contributions to disparities in (1) access to DF/HCC care and (2) post-access enrollment. RESULTS: Of 3698 individuals with acute leukemia, 85.9% were NHW, 4.5% HW, 4.3% NHB, 3.7% NHA, and 1.3% Other. Access was lower for HW (age- and sex-adjusted OR = 0.64, 95% CI = 0.45 to 0.90) and reduced post-access enrollment for HW (aOR = 0.54, 95% CI =0.34 to 0.86) and NHB (aOR = 0.60, 95% CI = 0.39 to 0.92) compared to NHW. Payor and socioeconomic status (SES) accounted for 25.2% and 21.2% of the +1.1% absolute difference in HW access. Marital status and SES accounted for 8.0% and 7.0% of the -8.8% absolute disparity in HW enrollment; 76.4% of the disparity was unexplained. SES and marital status accounted for 8.2% and 7.1% of the -9.1% absolute disparity in NHB enrollment; 73.0% of the disparity was unexplained. CONCLUSIONS: A substantial proportion of racial and ethnic inequities in acute leukemia trial enrollment at CCCs are from post-access enrollment, the majority of which was not explained by sociodemographic factors.

Risk factors associated with suicide among leukemia patients: A Surveillance, Epidemiology, and End Results analysis.

Previous studies have found that the risk of suicide is higher in patients diagnosed with cancer than in the general population. We aimed to identify potential risk factors associated with suicide in leukemia patients by analyzing data obtained from the Surveillance, Epidemiology, and End Results (SEER) database. We screened the SEER database for leukemia patients added between 1975 and 2017, and calculated their suicide rate and standardized mortality rate (SMR) relative to the total United States population from 1981 to 2017 as a reference. Univariate and multivariate Cox regression analyses were used to determine the risk factors for suicide in leukemia patients. We collected 142,386 leukemia patients who had been added to the SEER database from 1975 to 2017, of whom 191 patients committed suicide over an observation period of 95,397 person-years. The suicide rate of leukemia patients was 26.41 per 100,000 person-years, and hence the SMR of the suicided leukemia patients was 2.16 (95% confidence interval [CI] = 1.85-2.47). The univariate and multivariate Cox regression analyses showed that a high risk of suicide was associated with male sex (vs. female: hazard ratio [HR] = 4.41, 95% CI = 2.93-6.63, p < 0.001), older age at diagnosis (60-69 years vs. ≤39 years: HR = 2.60, 95% CI = 1.60-4.23, p < 0.001; 70-79 years vs. ≤39 years: HR = 2.84, 95% CI = 1.72-4.68, p < 0.001; ≥80 years vs. ≤39 years: HR = 2.94, 95% CI = 1.65-5.21, p < 0.001), white race (vs. black: HR = 6.80, 95% CI = 1.69-27.40, p = 0.007), acute myeloid leukemia (vs. lymphocytic leukemia: HR = 1.59, 95% CI = 1.09-2.33, p = 0.016), unspecified and other specified leukemia (vs. lymphocytic leukemia: HR = 2.72, 95% CI = 1.55-4.75, p < 0.001), and living in a small city (vs. large city: HR = 2.10, 95% CI = 1.23-3.60, p = 0.007). Meanwhile, being a non-Hispanic black (vs. Hispanic: HR = 0.06, 95% CI = 0.01-0.62, p = 0.019) was a protective factor for suicide. Male sex, older age at diagnosis, white race, and acute myeloid leukemia were risk factors for suicide in leukemia patients, while being a non-Hispanic black was a protective factor. Medical workers should, therefore, provide targeted preventive measures to leukemia patients with a high risk of suicide.

Pediatric leukemia could be driven predominantly by non-synonymous variants in mitochondrial complex V in Mizo population from Northeast India.

Leukemia is the most common childhood malignancy and studies had been carried out with promising revelations in its diagnosis and prognosis. However, majority of the studies are focused on nuclear alterations, while mitochondrial mutations are not well studied. Although there are studies of mitochondrial mutations in the adult leukemias, it does not represent the same for childhood malignancy. This is the first scientific report on the mtDNA mutational pattern of pediatric leukemic cases from a endogamous tribal population in Northeast India. ATP6 involved in the Complex V was found to be more altered with respect to the Non-synonymous variants. mtDNA variations in the non-coding region (D-Loop - g.152 T>C) and in the coding region (MT-ND2, g.4824 A>G, p.T119A) showed a maternal inheritance which could reveal a genetic predisposition with lower penetrance. D-Loop variant (g.152 T>C) could be a diagnostic marker in accordance with previous report but is in contrast to pertaining only in AML - M3 subtype rather was found across in myeloid malignancies.

Childhood central nervous system tumors and leukemia: Incidence and familial risk. A comparative population-based study in Utah and Norway.

BACKGROUND: In this study, we aimed to evaluate incidence rates and family risk of the most common childhood cancers, tumors in the central nervous system (CNS), and leukemia among individuals from Norway and individuals with Scandinavian ancestry living in Utah. METHODS: We used the Utah Population Database and the Norwegian National Population Register linked to Cancer registries to identify cancers in children born between 1966 and 2015 and their first-degree relatives. We calculated incidence rates and hazards ratios. RESULTS: The overall incidence of CNS tumors increased with consecutive birth cohorts similarly in Utah and Norway (both P < 0.001). Incidence rates of leukemia were more stable and similar in both Utah and in Norway with 4.6/100 000 person-years among children (<15 years) born in the last cohort. A family history of CNS tumors was significantly associated with risk of childhood CNS tumors in Utah HR = 3.05 (95% CI 1.80-5.16) and Norway HR = 2.87 (95% CI 2.20-3.74). In Norway, children with a first-degree relative diagnosed with leukemia had high risk of leukemia (HR = 2.39, 95% CI 1.61-3.55). CONCLUSION: Despite geographical distance and assumed large lifestyle differences, two genetically linked pediatric populations show similar incidences of CNS tumors and leukemia in the period 1966-2015. CNS tumors and leukemia aggregated in families in both countries.

The relationship between leukemia and TP53 gene codon Arg72Pro polymorphism: analysis in a multi-ethnic population.

Aim: Many studies have analyzed the relationship between Arg72Pro polymorphism of TP53 and leukemia; nevertheless, the findings continue to be indeterminate. We, therefore, performed an updated meta-analysis in multi-ethnic groups using specialized software for genome-wide association studies meta-analysis. Materials & methods: PubMed, EMBASE and Google Scholar were searched up to October 2018. An odds ratio (OR) with the corresponding 95% CI was used to evaluate the strength in the association. Results: This meta-analysis included 16 studies with 2337 cases and 9494 controls. In the overall population, significant relationship between Arg72Pro polymorphism of TP53 and leukemia susceptibility was found in two genetic models (recessive model: OR = 1.276, 95% CI = 1.102-1.476; p = 0.01; overdominant model: OR = 0.891, 95% CI = 0.802-0.988; p = 0.03). In stratified studies with ethnicity, a significant association was found in five ethnic groups, including Chinese, Americans, Africans, Japanese and Indians. Conclusion: We demonstrated that an association exist between leukemia risk and TP53 gene codon Arg72Pro polymorphism in the recessive and overdominant genetic models. Also, our findings show that the TP53 Arg72Pro polymorphism may influence leukemia development in different populations.

Effects of GST null genotypes on individual susceptibility to leukemia: A meta-analysis.

BACKGROUND: Whether glutathione S-transferases (GST) null genotypes influence individual susceptibility to leukemia remains controversial. Thus, we performed this meta-analysis to better analyze potential influences of GST null genotypes on individual susceptibility to leukemia. METHODS: Literature retrieve was conducted in PubMed, Web of Science and Embase. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. RESULTS: Totally fifty-one studies were enrolled for analyses. Significant associations with elevated individual susceptibility to leukemia were detected for GSTM1 (p < .0001, OR = 1.28, 95%CI 1.16-1.41), GSTP1 (p = .003, OR = 1.22, 95%CI 1.07-1.40) and GSTT1 (p < .0001, OR = 1.53, 95%CI 1.35-1.74) null genotypes in overall analyses. Further subgroup analyses by type of disease revealed that GSTM1, GSTP1 and GSTT1 null genotypes were all significantly associated with elevated individual susceptibility to acute lymphoblastic leukemia, GSTM1 and GSTT1 null genotypes were significantly associated with elevated individual susceptibility to acute myeloid leukemia, and GSTT1 null genotype was also significantly associated with elevated individual susceptibility to chronic leukemia. When we stratified data according to ethnicity of participants, positive results were found for all investigated variants in Caucasians and West Asians. Additionally, GSTM1 null genotype was also significantly correlated with elevated individual susceptibility to leukemia in East Asians. CONCLUSIONS: Our findings indicated that GSTM1, GSTT1 and GSTP1 null genotypes might serve as potential genetic biomarkers of leukemia in certain ethnicities.

The consensus on the monitoring, treatment, and prevention of leukemia relapse after allogeneic hematopoietic stem cell transplantation in China.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an important curative therapy for patients with leukemia. However, relapse remains the leading cause of death after transplantation. In recent years, substantial progress has been made by Chinese physicians in the field of establishment of novel transplant modality, patient selection, minimal residual disease (MRD) monitoring, and immunological therapies, such as modified donor lymphocyte infusion (DLI) and chimeric antigen receptor T (CART) cells, as well as MRD-directed intervention for relapse. Most of these unique systems are distinct from those in the Western world. In this consensus, we reviewed the efficacy of post-HSCT relapse management practice from available Chinese studies on behalf of the HSCT workgroup of the Chinese Society of Hematology, Chinese Medical Association, and compared these studies withthe consensus or guidelines outside China. We summarized the consensus on routine practices of post-HSCT relapse management in China and focused on the recommendations of MRD monitoring, risk stratification directed strategies, and modified DLI system. This consensus will likely contribute to the standardization of post-HSCT relapse management in China and become an inspiration for further international cooperation to refine global practices.

Racial Differences in Four Leukemia Subtypes: Comprehensive Descriptive Epidemiology.

Leukemia is a malignant progressive disease and has four major subtypes. Different racial groups differ significantly in multiple aspects. Our goal is to systematically and comprehensively quantify racial differences in leukemia. The SEER database is analyzed, and comprehensive descriptive analysis is provided for the four major subtypes, namely ALL (acute lymphoblastic leukemia), CLL (chronic lymphoblastic leukemia), AML (acute myeloid leukemia), and CML (chronic myeloid leukemia), and for two age groups (≤14 and >14) separately. The racial groups studied include NHW (non-Hispanic White), HW (Hispanic White), BL (Black), and API (Asian and Pacific Islander). Univariate and multivariate analyses are conducted to quantify racial differences in patients' characteristics, incidence, and survival. For patients' characteristics, significant racial differences are observed in gender, age at diagnosis, diagnosis era, using radiation for treatment, registry, cancer history, and histology type. For incidence, significant racial differences are observed, and the patterns vary across subtypes, gender, and age groups. For most of the subtypes and gender and age groups, Blacks have the worst five-year survival, and significant racial differences exist. This study provides a comprehensive epidemiologic description of racial differences for the four major leukemia subtypes in the U.S.

Small Numbers, Big Challenges: Adolescent and Young Adult Cancer Incidence and Survival in New Zealand.

PURPOSE: This study was undertaken to determine cancer survival and describe the unique spectrum of cancers diagnosed among New Zealand's adolescents and young adult (AYA) population. METHODS: Registrations for 1606 15-24 year olds diagnosed with a new primary malignant tumor between 2000 and 2009 were obtained from the New Zealand Cancer Registry and classified according to AYA diagnostic group and subgroup, age, sex, and prioritized ethnicity. Age-standardized incidence rates (IRs) per million person years and 5-year relative survival ratios were calculated. RESULTS: Cancer incidence was 228.6 per million for adolescents aged 15-19 years and 325.7 per million for young adults aged 20-24 years. Overall IRs were consistent across all ethnic groups but there were unique ethnic differences by tumor group including a higher incidence of bone tumors, carcinoma of the gastrointestinal tract, and gonadal germ cell tumors among Maori, a higher incidence of leukemia among Pacific peoples, and a higher incidence of melanoma among non-Maori/non-Pacific peoples. Five-year relative survival for adolescents (75.1%) and AYA overall (80.6%) appeared poorer than had been achieved in other high-income countries. Maori (69.5%) and Pacific (71.3%) AYA had lower 5-year survival compared to non-Maori/non-Pacific peoples (84.2%). CONCLUSION: The survival disparities observed require further investigation to identify and address the causes of these inferior outcomes. The newly established AYA Cancer Network Aotearoa has been tasked with improving cancer survival and care and ensuring equality of access for New Zealand AYAs with cancer.

Graft-versus-Host Disease after HLA-Matched Sibling Bone Marrow or Peripheral Blood Stem Cell Transplantation: Comparison of North American Caucasian and Japanese Populations.

The risk of acute graft-versus-host disease (GVHD) after HLA-matched sibling bone marrow transplantation (BMT) is lower in Japanese than in Caucasian patients. However, race may have differential effect on GVHD dependent on the graft source. North American Caucasian and Japanese patients receiving their first allogeneic BMT or peripheral blood stem cell transplantation from an HLA-matched sibling for leukemia were eligible. BMT was performed in 13% of the Caucasian patients and in 53% of the Japanese patients. On multivariate analysis, the interaction term between race and graft source was not significant in any of the models, indicating that graft source does not affect the impact of race on outcomes. The risk of grade III or IV acute GVHD was significantly lower in the Japanese patients compared with the Caucasian patients (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.57 to 0.96), which resulted in lower risk of nonrelapse mortality in the Japanese patients (HR, 0.69; 95% CI, 0.54 to 0.89). The risk of relapse was also lower in this group. The lower risks of nonrelapse mortality and relapse resulted in lower overall mortality rates among the Japanese patients. In conclusion, our data indicate that irrespective of graft source, the risk of severe acute GVHD is lower in Japanese patients, resulting in a lower risk of nonrelapse mortality.

Spectrum of mucocutaneous manifestations in an Asian cohort of patients with leukemia.

BACKGROUND: Literature on cutaneous manifestations of leukemia is limited. OBJECTIVE: To determine the pattern of mucocutaneous manifestations in adult Asian patients with leukemia and to establish their relation with the leukemia type. SUBJECTS AND METHODS: After previous consent, 196 consecutively registered patients with leukemia aged ≥18 years were recruited. All patients were prospectively followed for 3 months to evaluate the patterns of mucocutaneous involvement. The mucocutaneous manifestations were categorized into specific lesions with leukemic infiltration and non-specific lesions. RESULTS: Seventy-nine (40.3%) of 196 (males 128 and females 68) recruited patients showed one or more mucocutaneous manifestations. The total number of complaints observed was 87 with mean number of dermatoses per patient being 0.44. Specific manifestations (leukemia cutis) were present in six (3.06%) and nonspecific mucocutaneous manifestations in 73 (37.2%, reactive dermatoses n = 21 and infections n = 52). Cutaneous viral infections were significantly associated with acute lymphoblastic leukemia (P < 0.005). Antiviral prophylaxis with acyclovir significantly reduced the incidence of varicella-zoster infection (P = 0.016). CONCLUSION: Cutaneous manifestations are common in Asian patients with leukemia, and a thorough cutaneous examination will aid in their management.

PExFInS: An Integrative Post-GWAS Explorer for Functional Indels and SNPs.

Expression quantitative trait loci (eQTLs) mapping and linkage disequilibrium (LD) analysis have been widely employed to interpret findings of genome-wide association studies (GWAS). With the availability of deep sequencing data of 423 lymphoblastoid cell lines (LCLs) from six global populations and the microarray expression data, we performed eQTL analysis, identified more than 228 K SNP cis-eQTLs and 21 K indel cis-eQTLs and generated a LCL cis-eQTL database. We demonstrate that the percentages of population-shared and population-specific cis-eQTLs are comparable; while indel cis-eQTLs in the population-specific subsection make more contribution to gene expression variations than those in the population-shared subsection. We found cis-eQTLs, especially the population-shared cis-eQTLs are significantly enriched toward transcription start site. Moreover, the National Human Genome Research Institute cataloged GWAS SNPs are enriched for LCL cis-eQTLs. Specifically, 32.8% GWAS SNPs are LCL cis-eQTLs, among which 12.5% can be tagged by indel cis-eQTLs, suggesting the fundamental contribution of indel cis-eQTLs to GWAS association signals. To search for functional indels and SNPs tagging GWAS SNPs, a pipeline Post-GWAS Explorer for Functional Indels and SNPs (PExFInS) has been developed, integrating LD analysis, functional annotation from public databases, cis-eQTL mapping with our LCL cis-eQTL database and other published cis-eQTL datasets.

Overview of the National Occupational Mortality Surveillance (NOMS) system: leukemia and acute myocardial infarction risk by industry and occupation in 30 US states 1985-1999, 2003-2004, and 2007.

BACKGROUND: Cancer and chronic disease are leading causes of death in the US with an estimated cost of $46 billion. METHODS: We analyzed 11 million cause-specific deaths of US workers age 18-64 years in 30 states during 1985-1999, 2003-2004, and 2007 by occupation, industry, race, gender, and Hispanic origin. RESULTS: The highest significantly elevated proportionate leukemia mortality was observed in engineers, protective service, and advertising sales manager occupations and in banks/savings &loans/credit agencies, public safety, and public administration industries. The highest significantly elevated smoking-adjusted acute myocardial infarction mortality was noted in industrial and refractory machinery mechanics, farmers, mining machine operators, and agricultural worker occupations; and wholesale farm supplies, agricultural chemical, synthetic rubber, and agricultural crop industries. CONCLUSIONS: Significantly elevated risks for acute myocardial infarction and leukemia were observed across several occupations and industries that confirm existing reports and add new information. Interested investigators can access the NOMS website at http://www.cdc.gov/niosh/topics/NOMS/.

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.

Etoposide quinone is a covalent poison of human topoisomerase IIß.

Etoposide is a topoisomerase II poison that is utilized to treat a broad spectrum of human cancers. Despite its wide clinical use, 2-3% of patients treated with etoposide eventually develop treatment-related acute myeloid leukemias (t-AMLs) characterized by rearrangements of the MLL gene. The molecular basis underlying the development of these t-AMLs is not well understood; however, previous studies have implicated etoposide metabolites (i.e., etoposide quinone) and topoisomerase IIß in the leukemogenic process. Although interactions between etoposide quinone and topoisomerase IIα have been characterized, the effects of the drug metabolite on the activity of human topoisomerase IIß have not been reported. Thus, we examined the ability of etoposide quinone to poison human topoisomerase IIß. The quinone induced ~4 times more enzyme-mediated DNA cleavage than did the parent drug. Furthermore, the potency of etoposide quinone was ~2 times greater against topoisomerase IIß than it was against topoisomerase IIα, and the drug reacted ~2-4 times faster with the ß isoform. Etoposide quinone induced a higher ratio of double- to single-stranded breaks than etoposide, and its activity was less dependent on ATP. Whereas etoposide acts as an interfacial topoisomerase II poison, etoposide quinone displayed all of the hallmarks of a covalent poison: the activity of the metabolite was abolished by reducing agents, and the compound inactivated topoisomerase IIß when it was incubated with the enzyme prior to the addition of DNA. These results are consistent with the hypothesis that etoposide quinone contributes to etoposide-related leukemogenesis through an interaction with topoisomerase IIß.

Graft-versus-host disease and survival after cord blood transplantation for acute leukemia: a comparison of Japanese versus White populations.

An earlier report identified higher risks of acute and chronic graft-versus-host disease (GVHD) in White children compared with the Japanese after HLA-matched sibling transplantations. The current analysis explored whether racial differences are associated with GVHD risks after unrelated umbilical cord blood transplantation. Included are patients of Japanese descent (n = 257) and Whites (n = 260; 168 of 260 received antithymocyte globulin [ATG]). Transplants were performed in the United States or Japan between 2000 and 2009; patients were aged 16 years or younger, had acute leukemia, were in complete remission, and received a myeloablative conditioning regimen. The median ages of the Japanese and Whites who received ATG were younger at 5 years compared with 8 years for Whites who did not receive ATG. In all groups most transplants were mismatched at 1 or 2 HLA loci. Multivariate analysis found no differences in risks of acute GVHD between the Japanese and Whites. However, chronic GVHD was higher in Whites who did not receive ATG compared with the Japanese (hazard ratio, 2.16; P < .001), and treatment-related mortality was higher in Whites who received ATG compared with the Japanese (relative risk, 1.81; P = .01). Nevertheless, there were no significant differences in overall survival between the 3 groups.

XRCC1 Arg399Gln variation and leukemia susceptibility: evidence from 2,647 cases and 5,518 controls.

Previous reports implicate XRCC1 Arg399Gln polymorphism as a possible risk factor for several cancers. Increasing studies have been conducted on the association of XRCC1 Arg399Gln polymorphisms with susceptibility to leukemia. However, conflicting results have been generated. The goal of the present study was to derive a more precise estimation of the relationship. Meta-analyses assessing the association of XRCC1 Arg399Gln variation with leukemia were conducted, and subgroup analyses on ethnicity and clinical types were further performed. Eligible studies were identified for the period up to February 2013. Consequently, 16 publications including 17 case-control studies with 2,647 cases and 5,518 controls were selected for analysis. The overall data indicated a significant association of XRCC1 Arg399Gln polymorphism with leukemia risk (Gln/Gln versus Arg/Arg: OR = 1.37, 95% confidence interval (CI) = 1.08-1.74; dominant model: OR = 1.23, 95%CI = 1.03-1.46; recessive model: OR = 1.23, 95%CI = 1.06-1.44). In the subgroup analysis by ethnicity, Gln allele may increase leukemia susceptibility among Asians (Gln/Gln versus Arg/Arg: OR = 1.82, 95%CI = 1.19-2.78; dominant model: OR = 1.53, 95%CI = 1.00-2.33; recessive model: OR = 1.51, 95%CI = 1.11-2.06), but not Caucasians or mixed ethnicities. In the subgroup analysis by clinical types, increased risk was observed in acute lymphocytic leukemia (ALL) subgroup (Gln/Gln versus Arg/Arg: OR = 1.45, 95%CI = 1.09-1.93; recessive model: OR = 1.30, 95%CI = 1.00-1.69), but not in acute myeloid leukemia, chronic lymphocytic leukemia, or chronic myeloid leukemia subgroups, respectively. Collectively, the results of the present study suggest that XRCC1 Arg399Gln polymorphism might be a low-penetrant risk factor for leukemia, particularly among Asians. Homozygous Gln/Gln alleles might have a correlation with increased ALL susceptibility.

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.

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.