Guidelines from the World Health Organization and National Comprehensive Cancer Network recommend that all patients with diffuse large B-cell lymphoma (DLBCL) receive immunohistochemistry (IHC) as a surrogate of gene expression profiling to identify cell of origin and molecular testing by fluorescence in situ hybridization or karyotype to identify molecular/cytogenetic features. However, a study presented at the 2020 ASH Annual Meeting observed socioeconomic disparities related to the access to molecular testing for patients with DLBCL.
This retrospective cohort study analyzed the Flatiron Health electronic health record (EHR)-derived deidentified database and identified 5,387 adults with a diagnosis of DLBCL between January 2011 and December 2019. They assessed the following socioeconomic determinants of health: age, gender, type of insurance plan, race/ethnicity, and geographic location of residency.
The researchers observed that guideline-recommended diagnostic testing rates increased from 66.9% in 2011 to 85.6% in 2019 for IHC and from 49.5% to 67.0% for molecular testing (P<0.001 for both).
There was no association between any socioeconomic determinants and test utilization throughout the study period for IHC; however, patients who were older (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.96-0.98), female (OR, 0.77; 95% CI, 0.64-0.93), living in the northeast (OR, 0.75; 95% CI, 0.58-0.97), and uninsured (OR, 0.65; 95% CI, 0.51-0.82) had lower odds of undergoing molecular testing.
Compared with white patients, Asian patients were more likely to have molecular testing (OR, 4.06; 95% CI, 1.81-10.84); no association was found for other racial/ethnic groups.
“Providing equitable access to diagnostic testing would be a critical parameter for patients’ clinical benefit,” the researchers concluded.
Yang F, Abraham A, Zhang J, et al. Socioeconomic Disparities in Diagnostic Testing Among Patients with Diffuse Large B-Cell Lymphoma in the US. Abstract 2502. Presented at the 62nd American Society of Hematology Annual Meeting & Exposition, December 2-11, 2020.