Racial Differences in the Presentation and Outcomes of Chronic Lymphocytic Leukemia and Variants in the United States

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.

Evaluating population-level outcomes in Chronic Lymphocytic leukemia in the era of novel therapies using the SEER registry

In the last decade, novel agents such as BTK and BCL-2 inhibitors have revolutionized treatment of CLL/SLL, with clinical trials showing improved overall survival compared to chemotherapeutic agents. However, studies examining whether they have improved overall survival at the population level are lacking. We evaluated this by conducting a retrospective analysis of CLL/SLL patients registered in the National Cancer Institute's surveillance epidemiology and end results (SEER) database, analyzing overall survival (OS) in periods pre- and post-availability of novel agents, along with demographic information. Our results showed that median OS significantly improved over time [7.8 years (2000-2005), 9.1 years (2006-2013), and not reached (2014-2018) (p < 0.001)]. Compared to diagnosis in 2014-2018, diagnosis in earlier periods was associated with higher mortality risk (2000-2005-HR 1.32, 95 % CI 1.28-1.37, p < 0.001: 2006-2013-HR 1.09, 95 % CI 1.06-1.13, p < 0.001). Lower mortality risk was seen in patients age < 85 years whereas median household income of <$75000 was associated with higher mortality. Our study provides real-world data suggesting a possible multifactorial contribution to improvement in survival, including availability of novel agents, better monitoring, and supportive care. They also show discrepancies in overall survival for CLL/SLL patients due to socioeconomic status and demographic factors.

Results from a Real-World Multicenter Analysis of 482 Patients with Chronic Lymphocytic Leukemia Treated with Ibrutinib: A Look at Racial Differences

BACKGROUND

Despite recent approvals of lifesaving treatments for chronic lymphocytic leukemia (CLL), real-world data on the tolerability of the Bruton tyrosine kinase inhibitor ibrutinib for CLL treatment are lacking, especially in Black patients.

OBJECTIVE

To expand upon a previously reported retrospective chart review of ibrutinib-treated patients with CLL to increase the number of sites and the enrollment period in first-line (1L) and relapsed/refractory (R/R) settings with a subanalysis based on ethnicity.

PATIENTS AND METHODS

Adults with CLL who initiated ibrutinib treatment from five centers were followed for ≥ 6 months.

RESULTS

We identified 482 patients with CLL [405 White (153 1L, 252 R/R), 37 Black (17 1L, 20 R/R), 40 other/unidentified]. At baseline, 58.5% of all patients (68.8% of Black patients) had hypertension. At a median follow-up of 28.2 months, 31.1% of patients overall discontinued ibrutinib, 16.2% due to adverse events (12.2% 1L, 18.8% R/R). Overall, 46.0% of patients experienced ≥ 1 dose hold (40.2% 1L, 49.8% R/R), and 28.8% of patients experienced ≥ 1 dose reduction (24.9% 1L, 31.4% R/R). Among Black patients, ibrutinib was discontinued in 24.3% of patients (17.6% 1L, 30.0% R/R), 8.1% due to disease progression and 5.4% due to adverse events; 40.5% of patients experienced ≥ 1 dose hold (35.3% 1L, 45.0% R/R), and 32.4% of patients experienced ≥ 1 dose reduction (23.5% 1L, 40.0% R/R).

CONCLUSIONS

Toxicity and disease progression were the most common reasons for ibrutinib discontinuations in the overall population and among Black patients, respectively. Encouraging research participation of underrepresented patient groups will help clinicians better understand treatment outcomes.

Influence of racial and ethnic identity on overall survival in patients with chronic lymphocytic leukemia

Overall survival for chronic lymphocytic leukemia (CLL) patients by race; propensity score matched by age, Charlson-Deyo comorbidity score, insurance, and income and education level of zip code of residence.

Health disparity in use of novel agents for first-line therapy in Black and White patients with chronic lymphocytic leukemia in the Department of Veterans Affairs

BACKGROUND: Novel agents (NAs) (ibrutinib, idelalisib, and venetoclax) were first introduced in 2013 as therapeutic options to treat chronic lymphocytic leukemia (CLL). OBJECTIVES: To determine if the uptake of NAs for first-line treatment was similar in Black and White patients with CLL treated in the Department of Veterans Affairs (VA). METHODS: We conducted a retrospective cohort study including adults with CLL managed in the VA from October 1, 2013, to September 30, 2017. Descriptive statistics were used to summarize demographic data, and appropriate bivariable statistical tests were used to compare NA use, baseline characteristics, health outcomes, and complications. A multivariable logistic regression model was used to identify factors associated with uptake of NAs. The study included 565 patients; 86% were White and 14% were Black. Black patients were younger than White patients (median age [66 vs 69 years; P < 0.01]) but had similar median baseline Charlson comorbidity scores (4 vs 5). RESULTS: Overall, Black patients were less likely to receive NAs than White patients (14% vs 26%; P = 0.02). The gap narrowed over the study period: 4% vs 17% (2014), 13% vs 25% (2015), 17% vs 33% (2016), and 31% vs 33% (2017). Black race (P = 0.02) and fiscal year (P < 0.01) were the only variables significantly associated with NA use in the multivariable model. Health outcomes and most complications were similar for Black and White patients despite the difference in prescribing patterns. CONCLUSIONS: This is the first study to identify a potential health disparity with respect to use of NAs among Black and White patients with CLL treated in the VA. Fortunately, health outcomes and most complications were similar for Black and White patients despite the difference in prescribing patterns. DISCLOSURES: Funding for the study was provided by AstraZeneca as a research grant to the Foundation for Advancing Veterans' Health Research (FAVHR), a non-profit entity within the Audie L. Murphy Veterans Hospital, San Antonio, TX. Drs Nooruddin and Frei have received research grants (paid to FAVHR) from AstraZeneca in the last 3 years. Ms Ryan is an employee of AstraZeneca. The views expressed in this article are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs, the National Institutes of Health, or the authors' affiliated institutions.

Prognostic value of CD20 antigen mediated immune checkpoint inhibition in patients with acute or chronic lymphocytic leukemia: A protocol for systematic review

BACKGROUND

The addition of rituximab to standard chemotherapy has been shown to improve response rates in patients with acute or chronic lymphocytic leukemia. However, the prognostic factors associated with progression-free survival in rituximab treated patients with lymphocytic leukemias remains unclear. We will perform a comprehensive systematic review and meta-analysis on available data on prognostic factors associated with the clinical outcomes of patients with acute and chronic lymphocytic leukemia.

METHODS AND ANALYSIS

This protocol for a systematic review and meta-analysis of prognostic factors has been prepared following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015 guidelines. Electronic databases will be searched using keywords related to the objectives of this review. This systematic review and meta-analysis will include published randomized clinical trials, observational, prospective, and retrospective comparative cohorts. Two reviewers (ZAM and SAM) will independently screen studies, with a third reviewer consulted in cases of disagreements using a defined inclusion and exclusion criteria. Data items will be extracted using a predefined data extraction sheet. Moreover, the risk of bias and the quality of evidence were independently assessed using the quality in prognostic studies tool (QUIPS). The I2 and chi squared statistical tests will be used to analyze statistical heterogeneity across studies. An I2 values of > 50% will be considered substantial. All data analysis will be performed using STATA 16.0 (StataCorp LP, TX, USA). The outcomes examined will be progression-free and overall survival.

ETHICS AND DISSEMINATION

No ethical approval will be required and the findings of this meta-analysis will be published in a peer-reviewed journal.

SYSTEMATIC REVIEW REGISTRATION

International prospective Register of Systematic Reviews (PROSERO) number: CRD42021218997.

Racial and ethnic differences in all-cause mortality among Hispanics diagnosed with follicular lymphoma and chronic lymphocytic leukemia in the Bronx, NY

PURPOSE

Research suggests better survival among Hispanics with diffuse large B-cell lymphoma (DLBCL) compared to non-Hispanic Whites (NHW); however, less is known about racial/ethnic survival differences in follicular lymphoma (FL) and chronic lymphocytic leukemia (CLL).

METHODS

We identified incident FL and CLL cases diagnosed between 2005 and 2016 at Montefiore Medical Center in the Bronx, NY. Cox proportional hazards regression assessed the association between race/ethnicity and all-cause mortality among FL and CLL separately.

RESULTS

Of the 201 FL patients, 39.3% were NHW, 19.4% non-Hispanic Black (NHB), and 41.3% Hispanic, with a similar distribution among CLL patients. After adjusting for International Prognostic Index factors, sex, and chemotherapy, Hispanics with FL had lower all-cause mortality compared to NHWs (HR = 0.22; 95% CI 0.08-0.63), similar to prior DLBCL findings. All-cause mortality did not differ between NHBs and NHWs for FL or by any race/ethnicity for CLL.

CONCLUSION

In our diverse, urban population, we found that Hispanic diagnosed with FL had lower all-cause mortality compared to NHWs. We found no significant difference in all-cause mortality between Hispanics and NHWs diagnosed with CLL. Our study adds to the growing literature on racial and ethnic differences in survival among Hispanics with hematologic malignancies.

Racial disparities in the survival of patients with indolent non-Hodgkin lymphomas in the United States

There is a paucity of data regarding racial disparities in the survival of patients with indolent non-Hodgkin lymphomas (iNHL) in the contemporary time-period. Hence, we sought to determine whether racial disparities exist in the survival of patients with iNHLs in the US. We included 68 059 adult patients with follicular lymphoma (FL, n = 41 943), marginal zone lymphoma (MZL, n = 22 485), and lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM, n = 3631) who were diagnosed in the US between 2000 and 2017. Race was categorized as White, Black, Asian/Pacific Islander, or American Indian/Alaska Native (API/AI). The primary outcome was relative survival (RS), which was estimated using flexible parametric survival models. The RS estimates varied according to race and disease histology but were consistently lower for racial minorities, including those diagnosed during the most recent 5-year time-period of 2012-2017. On multivariable analysis for RS, Black patients with FL had a 32% higher excess mortality rate compared to White patients [adjusted excess hazard ratio (aEHR), 1.32; 95% CI, 1.15-1.51; p < .001], corresponding to a difference of 55 (95% CI, 24-86) excess deaths per 10 000 person-years. For MZL, Black patients had a 40% higher excess mortality rate compared to White patients (aEHR 1.40; 95% CI, 1.18-1.66; p < .001), corresponding to a difference of 62 (95% CI, 26-98) excess deaths per 10 000 person-years. No significant racial differences were detected for patients with WM. The greatest disparity was seen for younger Black patients with FL. Our findings highlight the need for interventions to improve the outcomes of Black patients with iNHLs, particularly younger Black patients with FL.

Perceptions of clinical care and research among African-American patients with lymphoma

Across lymphoma subtypes, African Americans experience disparities in clinical trial enrollment and outcomes. Understanding the needs of this population can aid addressing these disparities. Semi-structured interviews were conducted with 14 self-identified Black/African-American lymphoma patients to determine their perceptions and attitudes about aspects of treatment and research. Constant-comparative methods identified themes including trust in medical staff, lack of diagnosis information, interest in research, research priorities, and potentially unaddressed emotional needs. Patients trusted their doctors and desired more diagnosis information. Participants often did not consider the emotions surrounding their diagnoses and concentrated on positive attitudes during treatment. Most participants were interested in clinical trials to help future lymphoma patients. Participants suggested a range of future research topics emphasizing lymphoma etiology. Building on trusting doctor-patient relationships, expanding clinical trials information, addressing emotional needs, and aligning research objectives with patient concerns are potential strategies for increasing clinical trial enrollment among Black lymphoma patients.

Understanding and Addressing Disparities in Patients With Hematologic Malignancies: Approaches for Clinicians

Approximately 185,840 individuals will be diagnosed with hematologic malignancies in the United States in 2020. Disparities in disease incidence, prevalence, burden, mortality, and survivorship have been identified among this patient population. Contributing factors include genetic ancestry, race/ethnicity, sex, socioeconomic status, and geographic region. Historically, these inequities have been understudied. Addressing these disparities requires a systems-level approach, improving access to care and reducing biases in the clinical setting. Additional research is needed to construct comprehensive, multilevel models to explore systematic observational studies and perform strategic intervention trials to overcome these disparities.

Cancer health disparities in racial/ethnic minorities in the United States

There are well-established disparities in cancer incidence and outcomes by race/ethnicity that result from the interplay between structural, socioeconomic, socio-environmental, behavioural and biological factors. However, large research studies designed to investigate factors contributing to cancer aetiology and progression have mainly focused on populations of European origin. The limitations in clinicopathological and genetic data, as well as the reduced availability of biospecimens from diverse populations, contribute to the knowledge gap and have the potential to widen cancer health disparities. In this review, we summarise reported disparities and associated factors in the United States of America (USA) for the most common cancers (breast, prostate, lung and colon), and for a subset of other cancers that highlight the complexity of disparities (gastric, liver, pancreas and leukaemia). We focus on populations commonly identified and referred to as racial/ethnic minorities in the USA-African Americans/Blacks, American Indians and Alaska Natives, Asians, Native Hawaiians/other Pacific Islanders and Hispanics/Latinos. We conclude that even though substantial progress has been made in understanding the factors underlying cancer health disparities, marked inequities persist. Additional efforts are needed to include participants from diverse populations in the research of cancer aetiology, biology and treatment. Furthermore, to eliminate cancer health disparities, it will be necessary to facilitate access to, and utilisation of, health services to all individuals, and to address structural inequities, including racism, that disproportionally affect racial/ethnic minorities in the USA.

Racial and ethnic differences in diffuse large B-cell lymphoma survival among an underserved, urban population

Racial/ethnic differences in diffuse large B-cell lymphoma (DLBCL) survival have focused on non-Hispanic Whites (NHW) and non-Hispanic Blacks (NHB), often excluding Hispanics/Latinos. To further assess these racial/ethnic survival differences, we identified incident DLBCL cases diagnosed between 2005 and 2016 (n = 404; NHW = 136, NHB = 106, Hispanic/Latino = 162) at Montefiore Medical Center (Bronx, NY). All-cause mortality survival curves were assessed by the Kaplan-Meier method and log-rank test. Cox proportional hazards regression assessed the association between demographic/clinical factors and all-cause mortality. Hispanic/Latino patients experienced 52% lower risk of mortality compared to NHWs (HR = 0.48, 95%CI = 0.28-0.83), after adjusting for clinical prognostic factors. This reduced risk experienced by Hispanics/Latinos was similarly observed by age at diagnosis (≤60 years, >60 years), stage (I/II, III/IV), and receipt of chemotherapy. NHBs and NHWs experienced similar risk of mortality (HR = 0.85, 95%CI = 0.52-1.40). Overall, among DLBCL patients, Hispanics/Latinos had improved survival compared to NHWs. Additional research should seek to identify the drivers of this survival benefit.

Demographic pattern of chronic lymphocytic leukemia in a tertiary hospital in Calabar, South-South Nigeria

Background:

Chronic lymphocytic leukemia (CLL) is a heterogeneous group of monoclonal forms of lymphoproliferative disorder, which is usually common among older adults. There is an increasing trend in the number of patients presenting with the disease.

Aim:

This study aims to determine the epidemiology pattern of CLL in Cross River state.

Methodology:

A retrospective study with 10-years data (2010–2019) obtained from the register of the Department of Haematology and Blood Transfusion, University of Calabar Teaching Hospital, Calabar. The data collected include the date of presentation, the age, gender, location of residence, and occupations of the patients.

Results:

A total of 47 cases were seen during the 10-year period, with a male: female ratio of 1:1. The mean age at presentation was 59 years. The majority of the patients were in their fifth and sixth decades of life. Most patients (44.68%) practice farming as their profession.

Conclusion:

The study has reawaken our consciousness on the increasing trend on the epidemiological burden of CLL in our environment and will help to enhance further investigation into the relationship between the rising trend and available possible risk factors in our environment.

Delineation of clinical and biological factors associated with cutaneous squamous cell carcinoma among patients with chronic lymphocytic leukemia

BACKGROUND

The incidence of cutaneous squamous cell carcinoma (SCC) in patients with chronic lymphocytic leukemia (CLL) is significantly higher compared with age- and sex-matched controls.

OBJECTIVE

To evaluate the association of factors associated with SCC risk.

METHODS

Clinical CLL and SCC data were obtained from Mayo Clinic CLL Resource and self-reported questionnaires among patients with newly diagnosed CLL. We computed the CLL International Prognostic Index (CLL-IPI) from CLL prognostic factors, and a polygenic risk score from SCC susceptibility variants. We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Among 1269 patients with CLL, the median follow-up was 7 years, and SCC subsequently developed in 124 patients. Significant associations with SCC risk were history of skin cancer (HR=4.80; 95% CI: 3.37-6.83), CLL-IPI (HR=1.42; 95% CI: 1.13-1.80), and polygenic risk score (HR=2.58; 95% CI: 1.50-4.43). In a multivariable model, these factors were independent predictors (C statistic = 0.69; 95% CI: 0.62-0.76). T-cell immunosuppressive treatments were also associated with SCC risk (HR=2.29; 95% CI: 1.47-3.55; adjusted for age, sex, and prior SCC).

LIMITATIONS

The sample size decreases when combining all risk factors in a single model.

CONCLUSION

SCC risk includes history of skin cancer, an aggressive disease at time of CLL diagnosis, receiving T-cell immunosuppressive treatments, and high polygenic risk score. Future studies should develop prediction models that include these factors to improved screening guidelines.

Epidemiology and Etiology of Leukemia and Lymphoma

Available evidence suggests that the incidence of leukemia and lymphoma tends to be higher in highly developed regions of the world and among Whites in the United States. Temporal trends in incidence are dynamic and multifactorial; for instance, the incidence of non-Hodgkin's lymphoma increased around the turn of the century, in part because of the acquired immune deficiency syndrome (AIDS) epidemic. Most leukemias and lymphomas are sporadic and the specific etiology remains elusive. Still, research shows that these malignancies often develop in the context of genetic abnormalities, immunosuppression, and exposure to risk factors like ionizing radiation, carcinogenic chemicals, and oncogenic viruses. The prognosis varies by subtype, with poorer survival outcomes for acute leukemias among adults, and more favorable outcomes for Hodgkin's lymphoma. At a time when specific prevention efforts targeting these malignancies are nonexistent, there is a great need to ensure equitable access to diagnostic services and treatments worldwide.

Hematological malignancies in East Africa-Which cancers to expect and how to provide services

BACKGROUND

Sub-Saharan Africa (SSA) has an increasing non-communicable disease burden. Tanzania has an incidence of more than 35,000 cancer cases per year with an 80% mortality rate. Hematological malignancies account for 10% of these cases. The numbers will double within the next 10 years due to demographic changes, better diagnostic capabilities and life style changes. Kilimanjaro Christian Medical Centre established a Cancer Care Centre (CCC) in December 2016 for a catchment area of 15 million people in Northern Tanzania. This article aims to display the hematological diagnosis and characteristics of the patients as well as to describe the advancements of hematologic services in a low resource setting.

METHODS

A cross-sectional analysis of all hematological malignancies at CCC from December 2016 to May 2019 was performed and a narrative report provides information about diagnostic means, treatment and the use of synergies.

RESULTS

A total of 209 cases have been documented, the most common malignancies were NHL and MM with 44% and 20%. 36% of NHL cases, 16% of MM cases and 63% of CML cases were seen in patients under the age of 45. When subcategorized, CLL/SLL cases had a median age was 56.5, 51 years for those with other entities of NHL. Sexes were almost equally balanced in all NHL groups while clear male predominance was found in HL and CML.

DISCUSSION

Malignancies occur at a younger age and higher stages than in Western countries. It can be assumed that infections play a key role herein. Closing the gap of hematologic services in SSA can be achieved by adapting and reshaping existing infrastructure and partnering with international organizations.

Racial/ethnic, age and sex disparities in leukemia survival among adults in the United States during 1973-2014 period

There has been marked improvement in leukemia survival, particularly among children in recent time. However, the long-term trends in survival among adult leukemia patients and the associated sex and racial survival disparities are not well understood. We, therefore, evaluated the secular trends in survival improvement of leukemia patients from 1973 through 2014, using Surveillance Epidemiology and End-Result Survey Program (SEER) data. ICD-O-3 morphology codes were used to group leukemia into four types: acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML). Survival analysis for each leukemia type stratified by race/ethnicity, age, sex was performed to generate relative survival probability estimates for the baseline time period of 1973 through 1979. Hazard ratios (HR) and respective 95% confidence intervals (CIs) for survival within subsequent 10-year time periods by race, age and sex were calculated using Cox proportional hazard models. Of the 83,255 leukemia patients for the current analysis, the 5-year survival of patients with ALL, AML, CLL, and CML during 1973-1979 were 42.0%, 6.5%, 66.5%, and 20.9%, respectively. Compared to the baseline, there were substantial improvements of leukemia-specific survival in 2010-2014 among African-American (81.0%) and Asian (80.0%) patients with CML and among 20-49 year of age with CLL (96.0%). African-American patients, those with AML and those older than 75 years of age had the lowest survival improvements. Asians experienced some of the largest survival improvements during the study period. Others, including African-American and the elderly, have not benefited as much from advances in leukemia treatment.

Illness Perceptions in Chronic Lymphocytic Leukemia: Testing Leventhal's Self-regulatory Model

BACKGROUND

Leventhal's Self-regulatory Model proposes that somatic characteristics of a health threat (e.g., symptom severity), and prior experience with the threat (e.g., unsuccessful treatment), are determinants of illness perceptions. Chronic lymphocytic leukemia (CLL) is appropriate for test of these postulates, having three phases differing in symptom severity and prior treatment experiences: indolent disease requiring no treatment (active surveillance; AS), symptomatic disease requiring a first treatment (FT), and highly symptomatic disease in those who have relapsed and/or failed to respond to prior treatments (relapsed/refractory; RR).

PURPOSE

To test symptom severity and prior treatment experiences as determinants of illness perceptions, illness perceptions were characterized and contrasted between CLL groups.

METHODS

Three hundred and thirty CLL patients (AS, n = 100; FT, n = 78; RR, n = 152) provided illness perception data on one occasion during a surveillance visit (AS) or prior to beginning treatment (FT, RR).

RESULTS

Analysis of variance with planned comparisons revealed that consequences, identity, and concern were least favorable among RR patients, followed by FT, then AS (ps < .01). AS patients endorsed the lowest levels of coherence (ps < .01), and the most chronic illness timeline (ps < .01). FT patients endorsed the highest levels of personal and treatment control (ps < .01).

CONCLUSIONS

Data provide preliminary empirical support for Self-regulatory Model postulates that symptom severity and prior disease experiences influence illness perceptions. Unique knowledge needs for AS patients and elevated psychological/physical symptoms for later-stage CLL patients may warrant clinical attention.

Characterizing Lymphoma Incidence and Disparities for a Cancer Center Catchment Region

BACKGROUND

Racial disparities in non-Hodgkin lymphoma (NHL) are not well-elucidated for specific catchment areas, which can influence outcomes. Leveraging regional data from a population-based cancer registry may provide unique opportunities to quantify NHL disparities.

MATERIALS AND METHODS

Using Surveillance, Epidemiology, and End Results (SEER) data for NHL cases diagnosed in Georgia from 2001 to 2015, we examined NHL incidence rates by lymphoma subtype and racial differences in baseline characteristics and outcomes for diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). Cox regression models identified predictors of overall survival (OS).

RESULTS

SEER documented 38,504 NHL cases in Georgia from 2001 to 2015. The age-adjusted incidence rate for NHL in Georgia increased 1.03% per year, and the annual percentage change was 1.72 in blacks compared with 0.84 in whites. Compared with whites, blacks with DLBCL and FL were more likely to be diagnosed at a younger age (DLBCL, 54.1 vs. 65.5 years; P < .0001; FL, 58.4 vs. 64.0 years; P < .0001) and with B symptoms (DLBCL, 44.4% vs. 33.4%; P < .0001; FL, 28.5% vs. 21.4%; P = .004). Across racial categories, age at diagnosis > 60 years, advanced stage, and B symptoms predicted worse OS in DLBCL and FL. Blacks with DLBCL more commonly were diagnosed with stage III/IV disease (55.5% vs. 48.1%; P < .0001) and had worse 5-year relative survival (58.8% vs. 62.3%; P = .01).

CONCLUSIONS

Regional cancer registry data can be used to define incidence patterns and disparities in outcomes across NHL subtypes to help define key targets for interventions in a catchment area.

Health Disparities and the Global Landscape of Lymphoma Care Today

Lymphoma encompass a wide variety of distinct disease entities, including, but not limited to, subtypes of non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL). In the last 3 decades, therapeutic advancements have resulted in substantial improvements in lymphoma outcome. In most high-income regions, HL is a largely curable disease and for patients with two frequent subtypes of NHL, diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL), survival has dramatically improved with the incorporation of rituximab as a standard treatment approach. Despite these advances, outcomes vary between and across populations. This review will provide updated information about health disparities in lymphoma in the United States and across the globe.

Relations Between Residential Proximity to EPA-Designated Toxic Release Sites and Diffuse Large B-Cell Lymphoma Incidence

OBJECTIVES

Examining the spatial patterns of diffuse large B-cell lymphoma (DLBCL) incidence and residential proximity to toxic release locations may provide insight regarding environmental and sociodemographic risk factors.

METHODS

We linked and geocoded cancer incidence data for the period 1999-2008 from the Georgia Comprehensive Cancer Registry with population data from the US Census and the Environmental Protection Agency's Toxics Release Inventory. We conducted cluster analyses and constructed Poisson regression models to assess DLBCL incidence as a function of mean distance to the toxic release sites.

RESULTS

In total, 3851 incident DLBCL cases occurred among adults residing in Georgia between 1999 and 2008. Significant focal clustering was observed around 57% of ethylene oxide sites, 5% of benzene sites, 9% of tetrachloroethylene sites, 7% of styrene sites, 10% of formaldehyde sites, 5% of trichloroethylene sites, and 10% of all release sites. Mean distance to sites was significantly associated with DLBCL risk for all chemicals.

CONCLUSIONS

Proximity to Toxics Release Inventory sites can be linked to increased DLBCL risk as assessed through focal clustering and Poisson regression, and confirmatory studies using geospatial mapping can aid in further specifying risk factors for DLBCL.

Metabolism and Disposition of a Novel B-Cell Lymphoma-2 Inhibitor Venetoclax in Humans and Characterization of Its Unusual Metabolites

Venetoclax (ABT-199), a B-cell lymphoma-2 (Bcl-2) protein inhibitor, is currently in clinical development for the treatment of hematologic malignancies. We characterized the absorption, metabolism, and excretion of venetoclax in humans. After a single oral dose of [¹⁴C]venetoclax to healthy volunteers, the recovery of total radioactive dose was 100%, with feces being the major route of elimination of the administered dose, whereas urinary excretion was minimal (<0.1%). The extent of absorption was estimated to be at least 65%. Venetoclax was primarily cleared by hepatic metabolism (∼66% of the administered dose). ∼33% of the administered dose was recovered as the parent drug and its nitro reduction metabolite M30 [2-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-N-((3-amino-4-(((tetrahydro-2H-pyran-4-yl)methyl)amino)phenyl)sulfonyl)-4-(4-((4'-chloro-5,5-dimethyl-3,4,5,6-tetrahydro-[1,1'-biphenyl]-2-yl)methyl)piperazin-1-yl)benzamide] (13%) in feces. Biotransformation of venetoclax in humans primarily involves enzymatic oxidation on the dimethyl cyclohexenyl moiety, followed by sulfation and/or nitro reduction. Nitro reduction metabolites were likely formed by gut bacteria. Unchanged venetoclax was the major drug-related material in circulation, representing 72.8% of total plasma radioactivity. M27 (oxidation at the 6 position of cyclohexenyl ring followed by cyclization at the α-carbon of piperazine ring; 4-[(10aR,11aS)-7-(4-chlorophenyl)-9,9-dimethyl-1,3,4,6,8,10,10a,11a-octahydropyrazino[2,1-b][1,3]benzoxazin-2-yl]-N-[3-nitro-4-(tetrahydropyran-4-ylmethylamino)phenyl]sulfonyl-2-(1H-pyrrolo[2,3-b]pyridin-5-yloxy)benzamide) was identified as a major metabolite, representing 12% of total drug-related material. M27 was primarily formed by cytochrome P450 isoform 3A4 (CYP3A4). Steady-state plasma concentrations of M27 in human and preclinical species used for safety testing suggested that M27 is a disproportionate human metabolite. M27 is not expected to have clinically relevant on- or off-target pharmacologic activities.

Real-world clinical experience in the Connect® chronic lymphocytic leukaemia registry: a prospective cohort study of 1494 patients across 199 US centres

The clinical course of chronic lymphocytic leukaemia (CLL) is heterogeneous, and treatment options vary considerably. The Connect® CLL registry is a multicentre, prospective observational cohort study that provides a real-world perspective on the management of, and outcomes for, patients with CLL. Between 2010 and 2014, 1494 patients with CLL and that initiated therapy, were enrolled from 199 centres throughout the USA (179 community-, 17 academic-, and 3 government-based centres). Patients were grouped by line of therapy at enrolment (LOT). We describe the clinical and demographic characteristics of, and practice patterns for, patients with CLL enrolled in this treatment registry, providing patient-level observational data that represent real-world experiences in the USA. Fluorescence in situ hybridization (FISH) analyses were performed on 49·3% of patients at enrolment. The most common genetic abnormalities detected by FISH were del(13q) and trisomy 12 (45·7% and 20·8%, respectively). Differences in disease characteristics and comorbidities were observed between patients enrolled in LOT1 and combined LOT2/≥3 cohorts. Important trends observed include the infrequent use of genetic prognostic testing, and differences in patient characteristics for patients receiving chemoimmunotherapy combinations. These data represent experiences of patients with CLL in the USA, which may inform treatment decisions in everyday practice.

National trends in incidence and survival of chronic lymphocytic leukemia in Norway for 1953-2012: a systematic analysis of population-based data

Chronic lymphocytic leukemia is a disease of the elderly, and despite major advances in treatment, remains incurable. The Cancer Registry of Norway has registered data on patients with chronic lymphocytic leukemia since 1953. We aimed to analyze trends in incidence and survival of chronic lymphocytic leukemia in Norway. We identified 7664 patients reported with chronic lymphocytic leukemia to the registry between 1953 and 2012. We gathered information on sex, age at diagnosis, date of death and basis for diagnosis. The age‐standardized incidence increased from 0.6/100.000 person‐years in 1953 to 3.1/100,000 person‐years in 2012. We found a significant decrease in median age between 1993–2002 and 2003–2012 (75 vs. 72 years, 95%CI: 2.52–3.98, P < 0.001). Men were diagnosed at a significantly younger age than women. Immunophenotyping has become the most important diagnostic method after 2002. Median observed survival increased from 3 years in 1952–1963 to 8.5 years in 2003–2012. Five‐ and 10‐year age‐standardized net survival increased throughout the whole period across age groups and reached 79% and 57%, respectively. Median observed survival was significantly shorter in men than in women in 1993–2002 (4.9 vs. 6.1 years, P < 0.001). The gap between survival rates for men and women was diminishing in 2003–2012 in patients younger than 60 years while it remained considerable in older patients. Despite an aging Norwegian population, chronic lymphocytic leukemia (CLL) patients become younger at diagnosis. A fourfold increase in incidence, a prolonged survival, and major changes in diagnostic methods in Norway were observed.

Analysis of racial variations in disease characteristics, treatment patterns, and outcomes of patients with chronic lymphocytic leukemia

The impact of race on outcomes of patients with chronic lymphocytic leukemia (CLL), the most common leukemia in the west, is not well studied. We aimed to understand racial variations in clinical and disease characteristics, treatment patterns, and outcomes in patients with CLL. We utilized the Mayo Clinic CLL database to perform an analysis of these characteristics and natural history of non-white (NW) compared to white (W) CLL patients. Differences by race in median overall survival (OS) and time-to-first-treatment (TTFT) were investigated. Of the 4215 CLL patients, 4114 (97.6%) were W and 101 (2.4%) were NW. NW patients were younger (median age at diagnosis 59.4 vs. 63.4; P = 0.003) and more likely to have an elevated LDH (28.0% vs. 16.2%; P = 0.02). No differences in prognostic parameters were noted. No major differences were observed in treatment selection. OS and TTFT were similar between both groups. In the largest analysis of NW-CLL patients in North America, and contrary to historical retrospective reports, W and NW patients appear to have comparable outcomes when treated similarly. These findings suggest previously noted outcome differences may be due to disparities in access to care and management rather than differences in disease biology. Am. J. Hematol. 91:677-680, 2016. © 2016 Wiley Periodicals, Inc.

Practical approach to management of chronic lymphocytic leukemia

Revolutionary progress has recently changed the landscape of chronic lymphocytic leukemia (CLL). Powerful prognostic factors, especially p53 mutation and/or deletion and IGHV mutation status, have refined individual patient prognosis. Purine analogs and monoclonal antibodies paved the way from palliative treatment to chemoimmunotherapy capable of eradication of minimal residual disease and prolongation of survival. Obinutuzumab (GA-101) and ofatumumab have been recently approved for the treatment of comorbid patients. Bendamustine is available for first-line treatment of patients ineligible for fludarabine, cyclophosphamide, and rituximab (FCR). High-dose glucocorticoids combined with rituximab represent a promising option for refractory CLL; ofatumumab is approved for fludarabine- and alemtuzumab-refractory patients. Allogeneic stem cell transplantation is the only curative option but is feasible in a highly selected group of patients only. The novel small molecule inhibitors ibrutinib and idelalisib have been recently approved for relapsed/refractory CLL. This review provides practical advice for diagnosis, prognostication and treatment of CLL.

Disparities in conditional net survival among non-Hodgkin lymphoma survivors: a population-based analysis

We evaluated the association of baseline prognostic factors with conditional net survival among survivors of six subtypes non-Hodgkin lymphoma using the SEER program data from 2000-2012. Among 2-year survivors, further prognosis markedly improved in Burkitt's (BL) and diffuse large B-cell lymphoma (DLBCL), and became the same as for follicular lymphoma (5-year net survival ≥ 85%). Mantle cell lymphoma (MCL) demonstrated the worst prognosis of all studied histologies up to 5 years of survivorship. Age and stage lost prognostic significance in BL within 2 years from diagnosis. Racial disparities in net survival disappeared within 2 years for all subtypes, except in chronic lymphocytic leukemia, where black patients had persistently worse prognosis, and in MCL, where they had unexpectedly better prognosis than other races after 2 years. Many baseline factors may lose their initial prognostic value for lymphoma survivors, which should be considered when counseling patients about their prognosis and long-term surveillance.

Relative frequency of non-Hodgkin lymphoma subtypes in selected centres in North Africa, the middle east and India: a review of 971 cases

Comparative data regarding the distribution of non-Hodgkin lymphoma (NHL) subtypes in North Africa, the Middle East and India (NAF/ME/IN) is scarce in the literature. In this study, we evaluated the relative frequencies of NHL subtypes in this region. Five expert haematopathologists classified 971 consecutive cases of newly-diagnosed NHL from five countries in NAF/ME/IN. After review, 890 cases (91·7%) were confirmed to be NHL and compared to 399 cases from North America (NA). The male-to-female ratio was significantly higher in NAF/ME/IN (1·8) compared to NA (1·1; P< 0·05). The median ages of patients with low-grade (LG) and high-grade (HG) B-NHL in NAF/ME/IN (56 and 52 years, respectively) were significantly lower than in NA (64 and 68 years, respectively). In NAF/ME/IN, a significantly lower proportion of LG B-NHL (28·4%) and a higher proportion of HG B-NHL (58·4%) were found compared to NA (56·1% and 34·3%, respectively). Diffuse large B-cell lymphoma was more common in NAF/ME/IN (49·4%) compared to NA (29·3%), whereas follicular lymphoma was less common in NAF/ME/IN (12·4%) than in NA (33·6%). In conclusion, we found significant differences in NHL subtypes and clinical features between NAF/ME/IN and NA. Epidemiological studies are needed to better understand the pathobiology of these differences.

Population-specific prognostic models are needed to stratify outcomes for African-Americans with diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) demonstrates significant racial differences in age of onset, stage, and survival. To examine whether population-specific models improve prediction of outcomes for African-American (AA) patients with DLBCL, we utilized Surveillance, Epidemiology, and End Results data and compared stratification by the international prognostic index (IPI) in general and AA populations. We also constructed and compared prognostic models for general and AA populations using multivariable logistic regression (LR) and artificial neural network approaches. While the IPI adequately stratified outcomes for the general population, it failed to separate AA DLBCL patients into distinct risk groups. Our AA LR model identified age ≥ 55 (odds ratio 0.45, [95% CI: 0.36, 0.56], male sex (0.75, [0.60, 0.93]), and stage III/IV disease (0.43, [0.34, 0.54]) as adverse predictors of 5-year survival for AA patients. In addition, general-population prognostic models were poorly calibrated for AAs with DLBCL, indicating a need for validated AA-specific prognostic models.

To Each Its Own: Linking the Biology and Epidemiology of NHL Subtypes

Non-Hodgkin lymphoma (NHL) constitutes a diverse group of more than 40 subtypes, each characterized by distinct biologic and clinical features. Until recently, pinpointing genetic and epidemiologic risk factors for individual subtypes has been limited by the relative rarity of each. However, several large pooled case-control studies have provided sufficient statistical power for detecting etiologic differences and commonalities between subtypes and thus yield new insight into their unique epidemiologic backgrounds. Here, we review the subtype-specific medical, lifestyle, and biologic components identified in these studies, which suggest that a complex interplay between host genetics, autoimmune disorders, modifiable risk factors, and occupation contributes to lymphomagenesis.

Next-generation prognostic assessment for diffuse large B-cell lymphoma

Current standard of care therapy for diffuse large B-cell lymphoma (DLBCL) cures a majority of patients with additional benefit in salvage therapy and autologous stem cell transplant for patients who relapse. The next generation of prognostic models for DLBCL aims to more accurately stratify patients for novel therapies and risk-adapted treatment strategies. This review discusses the significance of host genetic and tumor genomic alterations seen in DLBCL, clinical and epidemiologic factors, and how each can be integrated into risk stratification algorithms. In the future, treatment prediction and prognostic model development and subsequent validation will require data from a large number of DLBCL patients to establish sufficient statistical power to correctly predict outcome. Novel modeling approaches can augment these efforts.

Race-specific features and outcomes of nodular lymphocyte-predominant Hodgkin lymphoma: Analysis of the National Cancer Data Base

BACKGROUND

The incidence of nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is higher among African Americans than among other races, but to the authors' knowledge, the characteristics of NLPHL in this population have not been evaluated. The authors compared clinical features, treatments, and survival of black and white patients with NLPHL using the National Cancer Data Base.

METHODS

The authors extracted the records of 602 black and 1950 white patients with NLPHL who were diagnosed between 1998 and 2011. Overall survival (OS) was compared using the log-rank test.

RESULTS

Black patients were on average younger than white patients (median age, 42 years vs 45 years; P =.0001), more often female (49% vs 29%; P<.0001), and more likely to have the axillary lymph nodes as the primary disease site (25% vs 17%; P =.0002). They also had unfavorable socioeconomic characteristics, a higher rate of no treatment in patients with early-stage disease, and a longer time to therapy initiation (median, 53.5 days vs 47 days; P<.0001). Despite this, the authors found no significant difference between the races with regard to stage distribution or survival (P =.39). OS at 7 years was 90.1% in patients with early-stage (American Joint Committee on Cancer stage IA/B, IIA) and 79.4% in patients with advanced stage (American Joint Committee on Cancer stage IIB, III/IV) NLPHL. Survival in the early stage of disease was not found to be significantly different after various treatment strategies (stratified log-rank P = .18), except that the administration of chemotherapy was associated with a better outcome in black patients (log-rank P =.011 vs P =.81 for white patients).

CONCLUSIONS

Differences in clinical presentation suggest the interaction of race-specific and sex-specific susceptibility factors for NLPHL. Further research is needed to elucidate these factors, and to investigate possible heterogeneous effects of treatments by race. Clinical trials comparing standard treatment strategies are unlikely to detect differences in OS among patients with early-stage NLPHL.

Gender and ethnic differences in incidence and survival of lymphoid neoplasm subtypes in an Asian population: Secular trends of a population-based cancer registry from 1998 to 2012

Descriptive epidemiology on incidence and survival by lymphoid neoplasm (LN) subtypes using the 2008 World Health Organisation (WHO) classification remained limited in Asia. The aim of this study was to evaluate whether gender and ethnic differences in incidence and survival of LN subtypes existed using the Singapore Cancer Registry (SCR) from 1998 to 2012. We derived age standardised incidence rates (ASIRs) by the direct standardisation method and 5-year relative survival (RSR) by the Ederer II method and period approach. Five-year observed survival (OS) was obtained for each ethnicity. Malays had the highest ASIR of total LNs among the three ethnicities for each time period. The largest increase in 5-year RSR subtypes was follicular lymphoma from 43.8% in 1998-2002 to 82.3% in 2008-2012; followed by chronic lymphocytic leukaemia (CLL)/small lymphocytic lymphoma (SLL) from 48.1% in 1998-2002 to 77.9% in 2008-2012. Although males had higher incidence than females in each time period, females had greater 5-year RSR for follicular lymphoma (89.8% in 2008-2012 for females vs. 76.6% in 2008-2012 for males) and CLL/SLL (78.7% in 2008-2012 for females vs. 76.7% in 2008-2012 for males). All three ethnicities experienced an overall increase in 5-year OS for mature B-cell lymphoma, with Indians experiencing the greatest increase (37.1% in 1998-2002 to 61.1% in 2008-2012), followed by Malays (30.8% in 1998-2002 to 48.7% in 2008-2012) and then Chinese (36.4% in 1998-2002 to 51.3% in 2008-2012). Our study demonstrated that improved mature B-cell lymphoma survival was not only observed in the West, but also in Singapore.

New insights into the epidemiology of non-Hodgkin lymphoma and implications for therapy

Non-Hodgkin lymphoma (NHL) comprises numerous biologically and clinically heterogeneous subtypes, with limited data examining the risk factors for these distinct disease entities. Many limitations exist when studying lymphoma epidemiology; therefore, until recently, little was known regarding the etiology of NHL subtypes. This review highlights the results of recent pooled analyses examining the risk factors for NHL subtypes. We outline the heterogeneity and commonality among the risk factors for NHL subtypes, with proposed subtype-specific as well as shared etiologic mechanisms. In addition, we describe how the study of lymphoma epidemiology may translate into prevention or therapeutic targeting as we continue to explore the complexities of lifestyle and genetic factors that impact lymphomagenesis.

Incidence of chronic lymphocytic leukemia and monoclonal B-cell lymphocytosis in Calgary, Alberta, Canada

This study provides an update on the incidence of chronic lymphocytic leukemia (CLL) and monoclonal B-cell lymphocytosis (MBL) in a major Canadian city using the 2008 World Health Organization (WHO) diagnostic criteria. Incidence calculations were performed using data from a centralized flow cytometry laboratory servicing southern Alberta, Canada. The age-standardized incidence of 4.01 cases of CLL per 100,000 person-years is nearly half the rate previously reported in Canada. Compared to previous criteria based on absolute lymphocyte count rather than absolute B-cell count, utilizing the 2008 WHO criteria resulted in a 47.6% decline in CLL incidence (8.42 cases per 100,000 using 1996 criteria). As a consequence, MBL rates are 64% higher. In contrast to 1996 criteria showing a peak CLL incidence between ages 70-74, age-specific incidence rates show a continuous increase with advancing age using the 2008 guidelines. We also report a higher male to female ratio of CLL than previous Canadian reports (1.80:1). CLL incidence in southern Alberta is lower than rates recently reported in the United States using the same criteria. This difference may be due in part to the low median age and the lower proportion of persons of Caucasian European ancestry present in our study population.

Racial differences in three major NHL subtypes: descriptive epidemiology

BACKGROUND

NHL (non-Hodgkin lymphoma) consists of over 60 subtypes, ranging from slow-growing to very aggressive. The three largest subtypes are DLBCL (diffuse large B-cell lymphoma), FL (follicular lymphoma), and CLL/SLL (chronic lymphocytic leukemia/small lymphocytic lymphoma). For each subtype, different racial groups have different presentations, etiologies, and prognosis patterns.

METHODS

SEER (Surveillance, Epidemiology, and End Results) data on DLBCL, FL, and CLL/SLL patients diagnosed between 1992 and 2010 were analyzed. Racial groups studied included NHW (non-Hispanic whites), HW (Hispanic whites), blacks, and API (Asians and Pacific Islanders). Patient characteristics, age-adjusted incidence rate, and survival were compared across races. Stratification and multivariate analysis were conducted.

RESULTS

There are significant racial differences for patients' characteristics, including gender, age at diagnosis, stage, lymph site, and age, and the patterns vary across subtypes. NHWs have the highest incidence rates for all three subtypes, followed by HWs (DLBCL and FL) and blacks (CLL/SLL). The dependence of the incidence rate on age and gender varies across subtypes. For all three subtypes, NHWs have the highest five-year relative survival rates, followed by HWs. When stratified by stage, racial difference is significant in multiple multivariate Cox regression analyses.

CONCLUSIONS

Racial differences exist among DLBCL, FL, and CLL/SLL patients in the U.S. in terms of characteristics, incidence, and survival. The patterns vary across subtypes. More data collection and analysis are needed to more comprehensively describe and interpret the across-race and subtype differences.

Racial differences in mantle cell lymphoma in the United States

Background

MCL (mantle cell lymphoma) is a rare subtype of NHL (non-Hodgkin lymphoma) with mostly poor prognosis. Different races have different etiology, presentation, and progression patterns.

Methods

Data were analyzed on MCL patients in the United States reported to the SEER (Surveillance, Epidemiology, and End Results) database between 1992 and 2009. SEER contains the most comprehensive population-based cancer information in the U.S., covering approximately 28% of the population. Racial groups analyzed included non-Hispanic whites, Hispanic whites, blacks, and Asians/PIs (Pacific Islanders). Patient characteristics, age-adjusted incidence rate, and survival rate were compared across races. Stratification by age, gender, and stage at diagnosis was considered. Multivariate analysis was conducted on survival.

Results

In the analysis of patients’ characteristics, distributions of gender, marital status, age at diagnosis, stage, and extranodal involvement were significantly different across races. For all three age groups and both male and female, non-Hispanic whites have the highest incidence rates. In the analysis of survival, for cancers diagnosed in the period of 1992–2004, no significant racial difference is observed. For cancers diagnosed in the period of 1999–2004, significant racial differences exist for the 40–64 age group and stage III and IV cancers.

Conclusions

Racial differences exist among MCL patients in the U.S. in terms of patients’ characteristics, incidence, and survival. More extended data collection and analysis are needed to more comprehensively describe and understand the racial differences.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-764) contains supplementary material, which is available to authorized users.

Fine-mapping of HLA associations with chronic lymphocytic leukemia in US populations

Chronic lymphocytic leukemia (CLL) displays remarkable ethnic predisposition for whites, with relative sparing of African-American and Asian populations. In addition, CLL displays among the highest familial predispositions of all hematologic malignancies, yet the genetic basis for these differences is not clearly defined. The highly polymorphic HLA genes of the major histocompatibility complex play a central role in immune surveillance and confer risk for autoimmune and infectious diseases and several different cancers, the role for which in the development of CLL has not been extensively investigated. The National Marrow Donor Program/Be The Match has collected HLA typing from CLL patients in need of allogeneic hematopoietic stem cell transplant and has recruited millions of volunteers to potentially donate hematopoietic stem cells. HLA genotypes for 3491 US white, 397 African-American, and 90 Hispanic CLL patients were compared with 50 000 controls per population from the donor registry. We identified several HLA alleles associated with CLL susceptibility in each population, reconfirming predisposing roles of HLA-A*02:01 and HLA-DRB4*01:01 in whites. Associations for haplotype DRB4*01:01∼DRB1*07:01∼DQB1*03:03 were replicated across all 3 populations. These findings provide a comprehensive assessment of the role of HLA in the development of severe CLL.

Residence proximity to benzene release sites is associated with increased incidence of non-Hodgkin lymphoma

BACKGROUND

An increased risk of non-Hodgkin lymphoma (NHL) has been observed among individuals with occupational exposure to benzene, but the risk among those living near benzene release sites has not been well described.

METHODS

To investigate the spatial patterns of NHL incidence and the association between NHL incidence and distance to benzene release sites, the authors linked and geocoded data on benzene release sites in Georgia from 1988 to 1998 using the Environmental Protection Agency's (EPA) Toxics Release Inventory (TRI), census tract level population statistics, and NHL incidence from the Georgia Comprehensive Cancer Registry (GCCR) from 1999 to 2008. Standardized incidence ratios were mapped by census tract, and a Poisson regression was performed on NHL and NHL subtype incidence data using the mean distance between the tract centroids and release sites as markers of exposure. Cluster analyses were conducted at the global, local, and focal levels.

RESULTS

Poisson regression indicated that, for every mile the average distance to benzene release sites increased, there was an expected 0.31% decrease in the risk of NHL. Similar results were observed for all NHL subtypes analyzed. Clusters of NHL were spatially associated with benzene release sites located in metropolitan areas, but not with release sites in other areas of the state.

CONCLUSIONS

NHL incidence was significantly higher in census tracts that were closer, on average, to benzene release sites. Additional studies are needed to examine spatial patterns of NHL incidence in other geographic regions and interactions between benzene and other exposures.

Clinical characteristics, response to therapy, and survival of African American patients diagnosed with chronic lymphocytic leukemia: joint experience of the MD Anderson Cancer Center and Duke University Medical Center

BACKGROUND

Little is known regarding racial disparities in characteristics and outcomes among patients with chronic lymphocytic leukemia (CLL).

METHODS

The characteristics and outcomes of untreated African American (AA) patients with CLL (n = 84) were analyzed and compared with a reference nonblack (NB) patient population (n = 1571).

RESULTS

At the time of presentation, AA patients had lower median hemoglobin levels (12.9 g/dL vs 13.7 g/dL), higher β2 microglobulin levels (2.7 mg/dL vs 2.4 mg/dL), greater frequency of constitutional symptoms (27% vs 10%), unmutated immunoglobulin heavy-chain variable region (IGHV) mutation status (65% vs 47%), ζ-chain-associated protein kinase 70 (ZAP70) expression (58% vs 32%), and deletion of chromosome 17p or chromosome 11q (28% vs 17%; P ≤ 02 for each comparison). Fifty-one percent of AA patients and 39% of NB patients required first-line therapy and 91% and 88%, respectively, received chemoimmunotherapy. Overall response rates to treatment were 85% for AA patients and 94% for NB patients (P = .06); and the complete response rates were 56% and 58%, respectively (P = .87). The median survival of AA patients was shorter compared with that of NB patients (event-free survival: 36 months vs 61 months; P = .007; overall survival: 152 months vs not reached; P = .0001). AA race was an independent predictor of shorter event-free and overall survival in multivariable regression models.

CONCLUSIONS

The current results indicated that AA patients with CLL have more unfavorable prognostic characteristics and shorter survival compared with their NB counterparts.

The role of chemotherapy in managing chronic lymphocytic leukemia: optimizing combinations with targeted therapy

For many years, alkylating agents were the standard treatment for chronic lymphocytic leukemia (CLL). The advent of purine analogs improved response rates, but not overall survival, and although the monoclonal antibody rituximab is generally active against B-cell malignancies, it has demonstrated limited benefits as monotherapy for the treatment of CLL. However, specific combinations of chemotherapy, antibodies and targeted therapies have demonstrated additive or synergistic activity in CLL cells and deliver substantial clinical benefits. A greater understanding of the actions of chemotherapies and targeted agents on cellular pathways will advance the development of rationally designed combinations corresponding to individual patients' disease profiles.