Ethnic Variations in Diagnosis, Treatment, Socioeconomic Status and Survival in a Large Population-Based Cohort of Elderly Patients with Non-Hodgkin’s Lymphoma

Background: Little is known about ethnic disparities in survival among patients with Non-Hodgkin’s Lymphoma (NHL), although these disparities have been documented for patients with many solid tumors.

Methods: We studied a retrospective cohort of 13,321 patients diagnosed with incident NHL at age >=65 in 1992–1999, identified from the SEER (Surveillance, Epidemiology and End Results)-Medicare linked database with 11 years of follow-up. Of these patients, 11,868 were Caucasians, 533 were African-Americans, and 920 were other ethnicities. A time-to-event Cox regression model was used to examine the relative risk of all-cause and disease-specific mortality.

Results: A larger proportion (72.2%) of African-Americans were in the poorest quartile of socioeconomic status as measured by the poverty level compared to 21.8% of Caucasians, and 43.2% of African-Americans received chemotherapy compared to 52.4% of Caucasians (p<0.01).

Hazard ratio of all-cause and NHL-specific mortality increased significantly with age, advanced tumor stage, higher comorbidity scores, and poorer socioeconomic status. Patients receiving either chemotherapy or radiotherapy or both were significantly less likely to die. Compared to Caucasians, African-Americans were not statistically significant at risk of all-cause (Hazard ratio = 0.97, 95% confidence interval: 0.88–1.08) and disease-specific mortality (1.07, 0.92–1.25), after adjusting for treatment, comorbidity, and socioeconomic status.

Conclusions: The risk of mortality in patients with NH-lymphoma was associated with socioeconomic status and was reduced in patients receiving chemotherapy. No significant differences in the risk of mortality were observed between African-American and Caucasian patients after controlling for factors such as treatment and socioeconomic status.