Racial Disparities in Chronic Lymphocytic Leukemia | Adam Kittai, MD | ASCO 2023

Hi, I'm Dr. Adam Kite. I am at the Ohio State University. I'm an assistant professor, and I specialize in the treatment of chronic lymphocytic leukemia and Richter's transformation. Today I'm going to talk about an abstract I have here at ASCO that's being presented on Monday that is a population-based research that looks at whether or not racial disparities exist for patients with CLL. So last ASCO we presented a poster and eventually manuscript that examined the SEER database and looked at patients who were diagnosed with CLL and looked at whether or not there was racial disparities present for Black patients versus white patients. And what we found was that using the SEER database, even in the era of modern therapies defined as since the year 2014, Black patients continue to fare worse than white patients using the SEER database. There were some limitations to this analysis. So we really couldn't tell what patients received. There is a way to look at Medicare data with SEER, but we didn't have that data and it really was difficult and you can't really tell what patients actually received for their treatment. We just were able to look at the time when a Brutonib was approved in 2014 as a variable in our analysis. So for this analysis that we're presenting on Monday, we use the Flatiron Health database and we were actually able to see what patients received to see if whether or not receiving small molecule inhibitors would change the disparity observed. So the Flatiron Health database is a group of academic and private practices. In order to have your data collected on the Flatiron Health database, you need to have been treated for your CLL. So this was anyone treated for CLL at various private practice and academic centers. And we looked at multiple variables including age, ECOG performance status, IGHV unmutated status as well as race and whether or not patients had received small molecule inhibitors at any time during their treatment. And what we found was that black patients continued to fare worse than white patients despite the use of small molecule inhibitors. The way we show this is by doing a multivariable analysis. Basically what this does is tells us that black race continues to be an independent prognostic variable for worse overall survival despite the use of small molecule inhibitors. So what this tells us is that even when patients are treated the same, that black patients continue to do worse despite their white counterparts. One of the interesting things that we found was we showed an interaction between age and black race. And what this tells us is that this hazard ratio for death is not the same across ages. And when we looked into this, it appeared that younger patients who were black had a much worse overall survival than white patients. And this was the primary driver for the disparity observed. We also found findings that patients who are black are more likely to get treated sooner after being diagnosed, which tells us they are likely coming to clinic later than their white counterparts. And also that there were higher rates of unmutated IGHV status, which is a worse prognostic finding, as well as the lesion 11q. So all told here, it appears that black race continues to be an independent prognostic variable for survival despite the use of small molecule inhibitors. That we need to do better in defining what or we need to do better in figuring out why our black patients continue to fare worse even when they are treated the same. This is also still hypothesis generating. And I think that this data needs to be corroborated with other healthcare databases given the unique aspects of the Flat Iron Health database that really is only looking at patients who have ever been treated for their CLL. So overall, we need to do more work to figure out why this disparity exists because it is very important and imperative that we figure out what's going on, whether or not it's societal issues, is it systemic racism, are there other reasons why our black patients continue to fare worse, including access to care amongst other reasons. So further work is needed. But this is an interesting finding to find that patients who are black continue to have a worse prognostic survival despite the use of small molecule inhibitors. On our multivariable analysis, in addition to finding that black race was an independent prognostic variable for survival despite the use of small molecule inhibitors, it also continued to be an independent prognostic variable despite the IGHV unmutated status and also higher ECOG performance status. ECOG performance status was a way that we tried to look at comorbidity. We're looking at other ways of looking at comorbidity in the Flat Iron Health database. And it's not the best way, but it was a way to look at comorbidity using a surrogate. So it is interesting that, you know, despite the higher or worse survival we should see with IGHV unmutated status, that wasn't the reason why our patients were, why the disparity was there. In addition, another interesting finding, which we're looking a little bit more into, is our black patients had received more small molecule inhibitors than our white patients. So using the Flat Iron Health database, there is a way of looking at sequencing, and we're looking at that data now. But what we decided to do, because it's hard to parse out sequencing, is look at whether or not patients ever received a small molecule inhibitor. And what we found was that when we compare black race to white race in this particular population, our black patients received more small molecule inhibitors than our white patients. And despite receiving more small molecule inhibitors, they continue to have a worse overall survival. So more research is needed. We still need to look more at more aspects of the Flat Iron Health database.