Access to Cancer Care Alleviates Racial Disparities in CLL/SLL

When access to cancer care is equal, racial disparities between Black patients and White patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) are alleviated, according to a study published in American Journal of Hematology.

These findings challenge previous studies that show Black patients had worse overall survival (OS) than White patients, based on Surveillance, Epidemiology, and End Results (SEER) age-adjusted death rates.

Although death rates from CLL/SLL continue to fall, with an average annual reduction of 2.9% between 2011 and 2020, there is concern that not all patients have benefitted from recent clinical advancements, such as the development of small module inhibitors (SMIs) and BCL2 inhibitors, the study authors wrote.

Nurse and patient | Image credit: CDavids - stock.adobe.com

“Given the limitations of variables in the SEER data, in-depth discovery of why this disparity exists was unable to be performed,” they said.

Instead, they utilized a large, real-world database to study differences in patient characteristics, CLL/SLL prognostic variables, and treatment received. They examined data from the nationwide Flatiron Health electronic health record (EHR)-derived de-identified database, which includes patients with CLL/SLL who received their diagnosis between January 2002 and June 2022.

The study included 7732 patients: 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. Overall, most patients received their diagnoses and started treatment for CLL/SLL between 2014 and 2022.

Analysis showed White patients were more likely to be male (63.4 % vs 55.1%; P = .0004), Black patients were younger at diagnosis than White patients (64.3 vs 66.6 years; P < .0001), more Black patients received their diagnosis after 2014 compared with White patients (67.2% vs. 57.3%; P < .0001), and most patients were from Southern states (44%).

Further analysis revealed that 37.9% and 30.8% of Black and White patients, respectively, were characterized as having obesity (body mass index, > 30 kg/m²), and Black patients were more likely than White patients to have a lower socioeconomic status (SES): 37.4% vs 11.9%. Eastern Cooperative Oncology Group performance status was balanced between the races.

The investigators highlighted the following diagnosis and treatment characteristics:

• At diagnosis, Black patients had a higher Rai stage, with 30.5% vs 22.6% of White patients having Rai stage of 3 or higher
• Black patients were less likely than White patients to have del(13q) (32.7% vs 51.9%; P < .0001) and more likely to have del(11q) (29.4% vs 17.4%; P < .0001) and trisomy 12 (38.4 % vs 27.6%; P < .001)
• Black patients were more likely to not have a mutation in IGHV (80.1% vs 58.2%; P < .0001)
• Black patients were more likely to be treated with SMIs at any time in their treatment history than White patients (68.1% vs 57%; P < .001)
• Black patients had a shorter average time from diagnosis to treatment start (24.3 vs 38.6 months; P < .0001)

“To our knowledge, this is the largest dataset that shows differences in CLL prognostic variables by race,” the investigators said.

Additionally, the study identified independent prognostic variables for worse OS: older age, male gender, presence of del(17p), and longer time from diagnosis to first treatment. Conversely, the use of SMIs and being from Western states were independent prognostic variables for improved OS.

Overall, these results suggest that when Black patients have access to cancer care and are treated with SMIs, no disparity in OS is observed, the authors stressed. However, inequity in access may still be prevalent, as Black patients tend to present with higher Rai stage and had a shorter time from diagnosis to treatment.

Speaking to potential limitations on their findings, the study authors noted that only patients being treated at a cancer clinic, who had access to a hematologist/oncologist, were included in this dataset, thus nullifying a potential source of disparity, the authors explained. Further, the database only starts accumulating data when a patient establishes care with a hematologist/oncologist, so it was not possible to directly assess delays in access to care, they added.

“Seeing no difference in overall survival between Black and White patients in a large, population-based study is promising,” they said, although no comparison could be made between patients who had access to cancer care and those who did not, given the patient population of the dataset.

According to the authors, the “clear difference” between the de-identified database they used and the SEER database is access to cancer-directed care, where the SEER database includes all patients regardless of treatment status and whether access to a hematologist/oncologist occurred.

“This analysis confirms that when access to cancer care is equal, racial disparities are alleviated,” the authors concluded. Nevertheless, they acknowledged that systemic issues remain, especially when the SEER data continue to show that a disparity exists, highlighting the need to reduce barriers to access.

“Future interventions aimed at improving disparities in cancer care should be aimed at improving overall access to care,” they concluded.

Reference

Kittai AS, Hang Y, Bhat SA, et al. Racial disparities in chronic lymphocytic leukemia/small lymphocytic lymphoma accounting for small molecule inhibitors: a real-world cohort analysis. Am J Hematol. Published online February 15, 2024. doi:10.1002/ajh.27241