Diffuse large B-cell lymphoma (DLBCL) is an aggressive subtype of non-Hodgkin lymphoma that tends to predominantly affect patients who identify as White with a median age of onset around 64 years. There is limited data available on the incidence and survival rates of DLBCL in adolescents and young adults (AYA). As such, a team of researchers conducted a study to determine the influence of race on the occurrence and survival outcomes of DLBCL among the AYA population.

Mustafa Wasifuddin, MD, Brookdale University Hospital and Medical Center, Brooklyn, New York, and colleagues gathered data from the Surveillance, Epidemiology, and End Results (SEER) database, specifically looking at DLBCL cases from 2000 to 2020 for patients within the AYA cohort, which was defined as individuals aged between 15 and 39 years old for the study. The objective was to quantify changes in the incidence of DLBCL and identify the factors that affect survival rates among different racial and ethnic groups.

The study identified a total of 8,735 AYA patients diagnosed with DLBCL. The researchers found that there was a noticeable decrease in the yearly incidence of DLBCL in the overall AYA cohort (annual percentage change (APC) of 0.5%, P < .05). Non-Hispanic Black (NHB) patients had the greatest decrease with an APC of -1.4% (P ≤ .001), followed by Hispanic patients of all races (APC of -0.65%, P ≤ .001), and Non-Hispanic White (NHW) patients with an APC of -0.57% (P ≤ .04). In contrast, the Non-Hispanic Asian/Pacific Islander (NHAPI) group demonstrated a significant increase in DLBCL during the same period with an APC of 1.88% (P ≤ .001).

In addition, there was a significant decrease in the proportion of patients with DLBCL among NHB patients (45% vs 55%, P ≤ .001) and NHW patients (45% vs 55%, P ≤ .001). A similar decrease followed in the Non-Hispanic American Indian/Alaska Natives (NHAIAN) group (48% vs 52%, P ≤ .001). The percentage of patients with DLBCL in the Hispanic group of all races did not change, with a constant rate of 50% throughout the period. Finally, the NHAPI group demonstrated the highest increase in proportion of patients with DLBCL (58%) in the period from 2011 to 2020 compared to the previous time period of 2000 to 2010 (42%, with a P ≤ .001).
The overall survival (OS) rates were the highest for the NHW group at 98 months (95% CI: 31-172, P ≤ .001), followed by the NHAPI group at 63 months (95% CI: 19-139, P ≤ .001), and the NHB group at 63 months (95% CI: 13-142, P ≤ .001). Both the NHAIAN group and the Hispanic group had the least OS at 58 months (95% CI: 21-147, P ≤ .001 and 95% CI: 14-134, P ≤ .001, respectively). 

The cancer-specific survival rates for 5 and 10 years among the AYA cohort were 68.1% for the NHAIAN (for both 5 and 10 years); 71.9% (5 years) and 69.4% (10 years) for the NHB group; 81.3% (5 years) and 80.3% (10 years) for the Hispanic group; 86.5% (5 years) and 85.4% (10 years) for the NHW group; and 85.4% (5 years) and 84.4% (10 years) for the NHAPI group.

In addition, a multivariable model identified associations between race and survival odds. Compared to NHW patients, NHB patients (hazard ratio (HR) = 1.91, 95% CI: 1.70-2.15, P ≤ .001), NHAIAN patients (HR = 2.09, 95% CI: 1.29-3.38, P ≤ .003), and Hispanic patients (all races) (HR 1.35, 95% CI: 1.20-1.53, P ≤ .001) had significantly reduced odds of survival.

The findings suggest that there was a significant overall decrease in the annual incidence of DLBCL within the AYA group during the study period. This decline was most striking among NHB patients, followed by Hispanic patients of all races and NHW patients. The research also identified a marked increase in DLBCL incidence within the NHAPI community.

Despite the significant reduction in DLBCL incidence among NHB patients, the study concluded that this group, along with NHAIAN, still has poorer survival odds in comparison to other racial and ethnic groups. The increase in the incidence of DLBCL was observed exclusively in NHAPI.

Overall, the study found a significant racial and ethnic disparity concerning the incidence and outcomes of DLBCL among AYA patients. By underscoring these disparities, the authors suggest the need for further research to comprehend the reasons behind such racial and ethnic disparities and subsequently improve the outcomes for these patient demographics.

Wasifuddin M, Ilerhunmwuwa NP, Becerra H, et al. Racial Disparities in the Incidence and Survival Outcomes in Diffuse Large B-Cell Lymphoma in Adolescents and Young Adults. Presented at: the 2023 ASH Annual Meeting & Exposition; December 9-12, 2023; San Diego, CA, and virtual; Abstract 384.