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

Survival Disparities of Diffuse Large B-Cell Lymphoma in a Community-Based Inner-City Cancer Center

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) comprises approximately 30% of all non-Hodgkin lymphomas. Multiple studies have demonstrated race-based disparities in survival among patients with DLBCL across all stages of disease, in the era both before and after rituximab. The etiology for the racial disparities in survival among patients with DLBCL is still unknown. Moreover, the Revised International Prognostic Index (R-IPI), a tool that predicts the DLBCL patients' outcome, has not yet been validated in African Americans (AA).

PATIENTS AND METHODS

We conducted a cohort study of patients diagnosed with DLBCL from January 1, 2007, to December 31, 2017, from our tumor registry in a single community-based inner-city cancer center. We abstracted demographic, clinical, histopathologic, treatment, and R-IPI variables. A total of 181 patients (47.5%) with biopsy-proven DLBCL were included in the retrospective analysis. The median age was 65 years, 47% were men, 41% were AA, and 44% were white.

RESULTS

The AA group had a younger median age, higher lactate dehydrogenase levels, higher frequency of B symptoms, and higher HIV infection than the non-AA group. The AA group had significantly decreased median overall survival than the non-AA group (15.7 months; 95% confidence interval, 10.3 to 23.9, vs. 93.6 months; 95% confidence interval, 61.5 to 142.6, respectively; P < .001). The survival disparities persisted after excluding patients with HIV and who did not receive chemotherapy. In addition, AA race predicts a reduced survival by univariate and multivariate analysis.

CONCLUSION

AA with DLBCL may have a poorer prognosis than the non-AA population. Further studies should investigate the biology of DLBCL in the AA population.

Remaining challenges in predicting patient outcomes for diffuse large B-cell lymphoma

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma and is an aggressive malignancy with heterogeneous outcomes. Diverse methods for DLBCL outcomes assessment ranging from clinical to genomic have been developed with variable predictive and prognostic success.Areas covered: The authors provide an overview of the various methods currently used to estimate prognosis in DLBCL patients. Models incorporating cell of origin, genomic features, sociodemographic factors, treatment effectiveness measures, and machine learning are described.Expert opinion: The clinical and genetic heterogeneity of DLBCL presents distinct challenges in predicting response to therapy and overall prognosis. Successful integration of predictive and prognostic tools in clinical trials and in a standard clinical workflow for DLBCL will likely require a combination of methods incorporating clinical, sociodemographic, and molecular factors with the aid of machine learning and high-dimensional data analysis.

Rural and urban patients with diffuse large B-cell and follicular lymphoma experience reduced overall survival: a National Cancer DataBase study

We examined 83,108 patients with diffuse large B-cell lymphoma (DLBCL) and 43,393 patients with follicular lymphoma (FL) to investigate disparities related to geographic population density, stratified as rural, urban, or metropolitan. We found that urban and rural patients less commonly had private insurance and high socioeconomic status. Urban and rural DLBCL patients were more likely to receive treatment within 14 days of diagnosis (OR 0.93, 95% confidence interval [CI] 0.89-0.98; and OR 0.81, 95% CI 0.72-0.91) while urban FL patients were more likely to have treatment >14 days after diagnosis (OR 1.08, 95% CI 1.01-1.16). Multivariable analyses demonstrated that rural and urban patients had worse overall survival with DLBCL (hazard ratio [HR] 1.09; 95% CI 1-1.19 and HR 1.08; 95% CI 1.04-1.11) and FL (HR 1.11; 95% CI 1.04-1.18 and HR 1.2; 95% CI 1.02-1.41), respectively, suggesting needs for focused study and interventions for these populations.

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.

A population-based multistate model for diffuse large B-cell lymphoma-specific mortality in older patients

BACKGROUND

Despite effective therapies, outcomes for diffuse large B-cell lymphoma (DLCBL) remain heterogeneous in older individuals due to comorbid diseases and variations in disease biology.

METHODS

Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, the authors conducted a multistate survival analysis of 11,780 patients with DLBCL who were aged ≥65 years at the time of diagnosis (2002-2009). Cox proportional hazards models were used to specify the impact of prognostic factors on overall survival and cause-specific deaths, and the Aalen-Johansen estimator was used to project the course of DLBCL over time with or without standard therapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP).

RESULTS

Advanced age (hazard ratio [HR] for ages 71-75 years: 1.25; HR for ages 76-80 years: 1.46; HR for ages 81-85 years: 1.88; and HR for age ≥86 years: 2.26), DLBCL stage (HR for Ann Arbor stage II: 1.28; HR for stage III: 1.54; and HR for stage IV: 1.95), Charlson Comorbidity Index (CCI) ≥1 (HR for CCI of 1, 1.15; and HR for CCI >1, 1.37), and not being married (HR, 1.12) were associated with an increased risk of DLBCL-specific death. Being female (HR, 0.91) and of higher socioeconomic status (HR, 0.91) were associated with a lower risk of DLBCL-related mortality after therapy. For patients treated with R-CHOP (3610 patients), the risk of death due to DLBCL was 14.0% and 18.6%, respectively, at 2 and 5 years of treatment and plateaued afterward, confirming a 5-year "cure" point while receiving R-CHOP among older patients.

CONCLUSIONS

Conducting a survival analysis over a large data set, the current study evaluated competing risks for death within a multistate modeling framework, and identified age, sex, and CCI as risk factors for DLBCL-specific and other causes of death.

Disparities in lymphoma on the basis of race, gender, HIV status, and sexual orientation

Lymphoid malignancies account for the sixth leading cause of death in the US, and, although survival is improving overall, this trend is not applicable to all patients. In this review, we describe disparities in the initial presentation, treatment, and outcomes across a diverse group of lymphoma patients on the basis of gender, race, HIV status, and sexual orientation. Identifying these disparities will hopefully lead to improved outcomes in these groups of lymphoma patients in the future.

Prognostic modeling in diffuse large B-cell lymphoma in the era of immunochemotherapy: Where do we go from here?

The model and approach described by Howlader et al could form a foundation for future risk‐prediction models that incorporate data on known differences in demographic, socioeconomic, clinical, and biological factors. Data from large diffuse large B‐cell lymphoma patient cohorts that capture host and tumor genomics and known clinical prognostic factors will be necessary to provide the resources for constructing meaningful prognostic models and to establish prediction models that will allow us to limit therapy and therapy‐related toxicity for favorable subsets of patients while optimizing directed approaches for poor‐risk subsets.

See also pages 3326‐34.