At the 65th American Society of Hematology (ASH) Annual Meeting, Ira L Zackon, MD, spoke on the real-world data from a large community oncology setting on the racial disparities observed in chronic lymphocytic leukemia treatment, which have led to poorer survival rates among particular populations of patients with CLL. This research may contribute to developing interventions to ensure that progress in CLL therapy benefits all patients.

Transcript:

I am Dr. Ira Zackon. I am a senior medical director with Ontada doing real-world data retrospective research, and I'm also a practicing hematologist in upstate New York taking care of the spectrum of both benign and malignant hematology. Our abstract presented at this ASH was in chronic lymphocytic leukemia, CLL, and using our database to look at a large population of patients with CLL with a particular focus: Are there any differences that we can see based on race or socioeconomic factors? I'll come back to kind of some of those details. 

First of all, the context for this was, we know our treatment of CLL has changed dramatically, going back to the introduction of [Bruton’s tyrosine kinase] (BTK) inhibitors in 2014, and then subsequently [B-cell lymphoma 2] (BCL2) inhibitors and how we use antibodies. This has really both improved outcomes and changed the way we treat. 

This study looked back to that period of January 2015 with data through the end of June 2023, an 8-year period, to kind of overlap with this time of change in the way we treat CLL. We identified over 12,000 patients. This was sourced in the electronic health record called Innomed, that's used across the US Oncology Network. This is community-based hematology-oncology, the US Oncology Network being the largest aggregated group of based oncology. We have access to finding that a larger number of patients. When you take those over 12,000 patients, and we looked at first race, we saw that 91% of the patients were White, 5% Black, and 4% other, and that still aligns reasonably with what we expect in the population statistics for CLL. 

But, when you look within the Black versus White population, we could see several observations. One is that there was a significant difference in a younger age of diagnosis by 2 years. In the Black population, [it is] 68 years old versus 70 years old in the White population. Black patients presented with more advanced stage---stage 3 or 4 CLL, 55%---compared to 45% in White [patients]. 

The 2 measures we did for socioeconomic status or social determinants of health were level of education and total household income, stratifying less than $30,000, or more than $30,000. We were using structured data. These are elements that are entered. It's part of patient care. So it's a kind of a larger look at this. The primary outcome we looked at was overall survival.

There, we saw that the rate of mortality, a death event, was 61% in the Black population compared to 43% only in the White population---almost [a] 20% difference. That is giving us a significant story. When you go back then to the elements of the patient, the characteristics and these social determinants of health that we measured and adjust for them, we saw that household income less than $30,000 remains the most statistically significant. Race alone wasn't statistically significant at that level, but of course, [it is] still clinically and socially significant in terms of Black patients with CLL. 

I should also say that level of income parameter [was] only captured in about 25% of the patients because it's not always entered. So, even though it only represents a significant minority, it still stood out as a significant potential driver. 

What we learn at a high level is first, importantly, we have to recognize that there's a difference in outcome. There are a lot of reasons underneath that, and social determinants are included in there. We recognize that it's not just the disease and therapy, but it's those other social determinants that determine the outcome. 

To really take this to a deeper level, we would need to do a larger study where we're doing chart reviews and getting at information that we can't so easily extract. We'd have to know that the disease isn't different in terms of our known prognostic factors. We need to look at the treatments delivered. Were they comparable? Were they on therapy for equally long? And then get more granular to what underlies the different social determinants in a more detailed level, because that's when we can, at the population level, hopefully, see if there are patterns that might drive what kind of interventions would be most important so that everyone gets the same therapy or certainly the same benefits [from] a therapy. 

Source: 

Su Z, O’Sullivan A, Marcus A, et al. Racial and socioeconomic disparities among patients with chronic lymphocytic leukemia (CLL) treated in the US community oncology setting. Presented at the ASH 65th Annual Meeting & Exposition; December 9-12 2023; San Diego, California. Abstract 2406