Presentation Characteristics, Risk Profiles and Long-Term Outcomes in a Public Health System, Minority Patient Population with Chronic Lymphocytic Leukemia.

BACKGROUND: Chronic lymphocytic leukemia (CLL) is noted to exhibit male predominance, median age of 65 years at diagnosis and variable survival. Little data exist however regarding the characteristics of CLL in the U.S. minority population.

METHODS: Data from 72 patients (pts) with CLL were collected from the primarily minority population served by Cook County Hospital, Chicago, Illinois over a 6 year period, and analyzed for clinical, presentation and prognostic characteristics and long-term survival. Continuous data were analyzed via Student’s T test and categorical data via Fisher’s Exact test. Survival was ascertained via Social Security Death Index query and analyzed using Kaplan Meier life-table analyses.

RESULTS: 72 pts [age at diagnosis 58.4 ± 12.1 yrs, range 31–94 yrs, 45 (62.5%) males, 27 (37.5%) females] were identified and analyzed as a retrospective cohort. 16 pts (22.2%) were < 50 yrs of age and the majority of pts (53, 73.6%) had ≥ 1 major medical comorbidity at presentation. 40 (55.5%) were African American (AA), 18 (25%) Caucasian, 6 (8.3%) Hispanic, 4 (5.5%) Middle Eastern, and 4 (5.5%) Asian. Distribution by Rai stage at diagnosis was as follows: 16 (22.2%) pts Stage 0, 17 (23.6%) Stage 1, 6 (8.3%) Stage 2, 16 (22.2%) Stage 3, 16 (22.2%) Stage 4 and 1(1.4%) Richter transformation. 17 pts (23.6%) were low risk, 24 (33.3%) were intermediate risk and 31 (43.1%) were high risk (HR). Of 65 pts in whom prognostic data were available 46 (70.8%) pts had 1 or more HR features of which 25 (54.3%) were AA. Poor prognosticators included clinical stage 3 and 4 (43.1%), beta2m > 5.0 (4%), diffuse involvement of BM (36.4%), ZAP-70 positivity (20%), CD38 positivity (15.7%) and poor cytogenetic profile (del 11q / del 17q, 23.7%). CLL-associated complications included AIHA in 8 (11.1%) pts, (3/8 Coomb’s positive), ITP in 1(1.4%) pt, hypogammaglobinemia in.20/27 (74.1%) tested pts, CLL transformation to DLBCL (Richter) in 1(1.4%) pt, and second malignancies in 6 (8.3%) pts. AA pts, comprising the largest ethnic subgroup, were significantly older than non-AA pts (60.9 ± 12.9 yrs vs 55.3 ± 10.5 yrs, p<0.0478) and were more likely to have >1 medical comorbidity than non- AA pts (55.6% vs 25.0%, p=0.014). Both advanced stage at presentation (Rai 3 and 4, AA:42.5% vs non-AA:46.9%, p=0.812) and high-risk profile (AA:67.5% vs non-AA:55.9%, p=0.34) were comparably distributed between AA and non-AA pts. A modest difference was noted between AA and non-AA pts in the likelihood of receiving treatment (52.5% vs 68.8%, p=0.23) however survival at mean follow-up of 26.5 ± 20.7 months was similar (90% vs 87.5%, p=1.0).

CONCLUSIONS: The primarily minority-based, public health system patient cohort analyzed in this observational study were somewhat younger than published historical control populations at the time of CLL diagnosis. African American pts while generally older and noted to have more comorbidities, had comparable disease stage and risk profiles at presentation as non-African American pts. The numerical disparity between proportions of AA vs non-AA pts treated did not appear to impact survival in this analysis. Further investigations of diagnostic, prognostic and healthcare disparities in the underserved minority population, are warranted.