Authored by Dr. Brian Koffman
Bottom Line:
Many studies show inferior outcomes in Black versus White chronic lymphocytic leukemia / small lymphocytic lymphoma (CLL / SLL) patients. In a recent large real-world study, overall survival (OS) was similar when access to cancer care was equal, suggesting eliminating barriers to care is needed.
Who Performed the Research and Where Was it Presented:
Dr Adam Kittai led a group of researchers with a letter published in the American Journal of Hematology: Racial disparities in chronic lymphocytic leukemia/small lymphocytic lymphoma accounting for small molecule inhibitors: A real-world cohort analysis.
Background:
CLL has long been known to be more common in older white males, making it harder to study other ethnic minorities. Also, poorer survival has been shown repeatedly in Blacks with CLL / SLL. For example, Dr. Kittai used the Surveillance, Epidemiology, and End Results (SEER) US population data that represented the entire US population well and found that black CLL / SLL patients lived on average nearly three years less than white between 2011 and 2020. This was mainly during the era of targeted therapies, with ibrutinib approved in 2014 and venetoclax in 2016. Another example is this review of SEER data presented at ASH 2022, from 2009 to 2019. Why are there these differences? Is it a result of:
- Genetic differences between the populations?
- Poorer responses to the new therapies?
- Different environmental, dietary, or socioeconomic factors?
- Difference in access to care?
- The difference in medication adherence?
- Systemic racism?
To answer the questions about why these differences exist, research must use a vast database that provides more granular data than SEER, which does not provide medical or socioeconomic details.
Methods and Participants:
Flatiron Health’s electronic health record (EHR) derived deidentified database was chosen. To be included in this real-world study as a CLL patient, there needed to be documentation of at least two hematologist/oncologist visits for CLL. More than 7,000 medical records were included. All the patients, black or white, assessed in this study had access to a hematologist/oncologist, which is critical in interpreting the results.
Results:
There is much data to review. These are only some of the highlights:
- 7732 patients were studied:
- 5864 (81.7%), 579 (8.1%), 63 (0.9%), 8 (0.1%), and 660 (9.2%) patients were White, Black, Asian, Hispanic or Latino, or Other/Not specific race, respectively.
- Black patients were younger when diagnosed (64.3 vs. 66.6 years, p < .0001) than White patients.
- White patients were often male (63.4% vs. 55.1%, p = .0004).
- Black patients were less likely to have been seen at an academic center than White patients (11.6% vs. 15.7%, p < .0001).
- Black patients were much more likely to score low on the socioeconomic status (SES) index compared to white patients (37.4% of Blacks having the lowest SES score vs. 11.9% of Whites).
- Rai stage was higher at the time of diagnosis in Blacks.
- FISH testing was performed at equal rates. 17p deletion rates were similar. Blacks were likely to have unmutated IGVH.
- Black patients started treatment sooner (24.3 vs. 38.6 months, p < .0001).
- Blacks were more likely to be treated with targeted oral therapy, specifically a BTKi or BCL2i, than White patients.
- With a median follow-up of 4.2 years, there was no difference in overall survival (OS).
Conclusions:
In this large, retrospective study we learn despite differences in disease biology, SES, and more advanced disease at the time of diagnosis, for Black individuals with CLL / SLL, when seen by a hematologist/oncologist with access to modern therapies, survival is essentially the same as White patients. Dr. Kim’s research on racial disparities using SEER compared to other databases had similar findings. This suggests barriers to care cause the worst outcomes when looking at population-based data and not medical records that, by their very nature, imply access to care.
Links and Resources:
Watch the interview on the abstract here:
The actual letter published in the American Journal of Hematology here: Racial disparities in chronic lymphocytic leukemia/small lymphocytic lymphoma accounting for small molecule inhibitors: A real-world cohort analysis.
Stay strong. We are all in this together
Brian Koffman, MDCM (retired), MS Ed
Co-Founder, Executive VP and Chief Medical Officer
CLL Society
