Baseline clinical characteristics of patients with chronic lymphocytic leukemia (CLL) from 11 Latin American countries: A real-world registry analysis

Abstract

Abstract Background: Chronic lymphocytic leukemia (CLL) exhibits diverse clinical manifestations, and access to diagnostic and staging tools varies significantly throughout Latin America (LATAM). To improve our understanding of how the disease presents and how it is treated in the region, we analyzed the baseline clinical characteristics, molecular findings, and outcomes of patients in a collaborative LATAM CLL registry. Methods: Retrospective data were collected on 4,649 CLL patients diagnosed between 2000 and 2024 in 11 Latin American countries: Argentina, Brazil, Chile, Colombia, Cuba, Guatemala, Mexico, Paraguay, Peru, Uruguay, and Venezuela. Brazilian Registry of CLL and GELL-CLL data. Results: The median age was 67 years (range 21–106), with a slight male predominance (58.6%). At diagnosis, the Binet stage was available for 4,249 patients. Of those, 62.1% were stage A, 21.7% were stage B, and 16.5% were stage C. Rai stage was available for 3,875 patients. Of those, 36.2% were stage 0, 23.0% were stage 1, 11.1% were stage 2, 5.9% were stage 3, and 7.1% were stage 4. ECOG performance status (n = 2,756) was 0 in 60.7% of patients, 1 in 29.2%, and ≥ 2 in 10.1%. Among the 1,648 patients with available CIRS scores, the median score was 4, and 35.4% had at least one comorbidity. Laboratory data showed elevated LDH in 29.0% (864 out of 2,983) and high β2-microglobulin in 46.3% (1,050 out of 2,269). Cytogenetic and molecular data were available for subsets of patients. The FISH panel with four probes was performed on 634 patients: 19% had del(13q), 16% had +12, 13% had del(11q), and 19% had del(17p). Isolated FISH for del(17p) was positive in 12% (122 out of 1,015), and TP53 mutations were detected in 16.4% (56 out of 342). IGHV mutation status was not systematically collected. After a median follow-up period of 49 months, the median treatment-free survival (TFS) was 38 months. TFS was significantly longer in private centers (46 months) than in public centers (31 months, P = 0.01). Among the 921 patients for whom data was available, TFS was shorter in those with del(17p) (13 versus 25 months, P = 0.005). Among the 543 patients with a full 4-probe FISH panel, the shortest TFS was observed in patients with del(17p) (23 months) and del(11q) (20 months), followed by +12 (31 months) and normal FISH (33 months). The longest TFS was observed in patients with del(13q) (60 months). Median overall survival (OS) was not reached. OS at 5 years was lower in public centers (88%) than in private centers (93%, P = 0.03), in patients with elevated β2-microglobulin (85% vs. 96%, P < 0.0001), in patients with elevated LDH (83% vs. 92% with normal values, P < 0.0001) and decreased progressively by Binet stage (95% for stage A, 85% for stage B, and 72% for stage C). Among the 921 patients with available data, OS was significantly lower in those with del(17p) (79%) than in those without (89%, P = 0.001). Conclusion: This large, multicenter, real-world registry highlights the clinical and therapeutic heterogeneity of chronic lymphocytic leukemia (CLL) in Latin America. Despite the predominance of early-stage disease, a significant proportion of patients present with high-risk features, such as del(17p), TP53 mutations, and elevated LDH or β2-microglobulin levels. Our findings corroborate the prognostic value of these biomarkers and underscore the limited availability of risk stratification tools in the region. These results underscore the necessity of expanding access to molecular diagnostics and strengthening medical education to promote evidence-based care for CLL in Latin America.