Restrictive Treatment Criteria Improve Prognosis Prediction in Chronic Lymphocytic Leukemia: Insights from the Brazilian Registry

Highlight

• The Brazilian Group of CLL (BGCLL) proposes more restrictive treatment initiation criteria compared to IWCLL guidelines in chronic lymphocytic leukemia (CLL).
• The BGCLL criteria use lower thresholds for cytopenias and exclude progressive lymphocytosis or symptoms without cytopenias as treatment triggers.
• Retrospective analysis of 2511 patients from the Brazilian CLL Registry shows restrictive criteria better predict prognosis and largely spare patients from unnecessary treatment.
• Patients treated for cytopenias exhibit significantly worse survival, underscoring cytopenia presence as a robust marker of disease burden.

Study Background

Chronic lymphocytic leukemia (CLL) is a heterogeneous hematological malignancy characterized by the clonal accumulation of mature B lymphocytes. Disease progression and clinical outcomes vary widely, necessitating tailored approaches to treatment initiation. The International Workshop on Chronic Lymphocytic Leukemia (IWCLL) guidelines have been the global standard, recommending treatment upon evidence of disease progression, symptoms, or cytopenias under defined thresholds. However, a more restrictive approach could potentially improve prognostic accuracy and avoid overtreatment.

In Brazil, the Brazilian Group of CLL (BGCLL) proposed stricter treatment initiation criteria focusing on deeper cytopenias and excluding progressive lymphocytosis or symptoms without cytopenias or masses as indications. Given the chronic, often indolent nature of CLL, optimizing when to start therapy is crucial for balancing efficacy with quality of life and treatment toxicity.

Study Design

This retrospective study evaluated 2511 CLL patients registered in the Brazilian CLL Registry from January 2009 to July 2023 with minimum requisite data available. Patients were classified according to two sets of criteria for treatment initiation: the IWCLL liberal criteria and the BGCLL restrictive criteria.

• BGCLL Criteria for Treatment Initiation: Cytopenias defined as hemoglobin <9.5 g/dL or platelets <50,000/mm³; progressive lymphocytosis and disease-related symptoms without cytopenias or symptomatic masses were excluded as treatment criteria.
• IWCLL Criteria: Cytopenias defined as hemoglobin <10 g/dL or platelets <100,000/mm³; progressive lymphocytosis and symptoms considered treatment indications.

Survival outcomes were assessed using Kaplan-Meier methods, with comparisons via log-rank tests. Cox proportional hazard models adjusted for relevant variables provided hazard ratios (HRs) with 95% confidence intervals (CIs). A P-value <0.05 was considered statistically significant.

Key Findings

The cohort comprised 2511 patients from 41 centers, with 1404 patients (56%) fulfilling IWCLL liberal criteria for treatment and 788 patients (31%) meeting BGCLL restrictive criteria:

Survival Outcomes Based on Criteria

• Patients meeting the BGCLL restrictive criteria had worse overall survival (68%) compared to those meeting the IWCLL liberal criteria (85%).
• This suggests that restrictive BGCLL criteria more effectively identify patients with higher disease burden and poorer prognosis.

Impact of Treatment Indications on Survival

• Patients treated specifically for cytopenias had significantly inferior overall survival (69%) than those treated for other indications (97%) (P <0.0001), confirming cytopenias as a marker of advanced disease.
• Notably, patients treated solely for disease-related symptoms, progressive lymphocytosis, or extranodal involvement had survival similar to untreated patients, indicating these factors without cytopenias might not necessitate immediate therapy.

Clinical Implications

The restrictive BGCLL approach allows clinicians to better distinguish between patients who require immediate treatment because of clinically significant cytopenias and those for whom watchful waiting remains appropriate. This is paramount in CLL, where early intervention in low-risk patients has not demonstrated survival benefits and may expose patients to avoidable toxicity.

Expert Commentary

This study reinforces the principle that initiating CLL treatment should be reserved for patients with clear indicators of disease progression likely to impact survival. The BGCLL restrictive criteria refine treatment triggers by emphasizing greater cytopenia severity thresholds and discounting symptoms or lymphocytosis when isolated. This approach aligns with growing evidence that asymptomatic increases in lymphocyte counts alone do not warrant treatment.

While retrospective, the large multicenter registry-based cohort underpins the robustness and generalizability of findings. However, limitations include the inability to directly compare treatment regimens or control for molecular prognostic factors. Prospective validation of these restrictive criteria could further define optimal timing for intervention in diverse populations.

Current advances in targeted therapies with improved safety profiles may challenge the paradigm of restrictive treatment initiation in the future, but until such time, prudent patient selection remains essential.

Conclusion

The Brazilian registry analysis provides compelling evidence that a restrictive, cytopenia-focused treatment initiation strategy in CLL better stratifies patients by prognosis and safely defers therapy in lower-risk individuals. Adoption of BGCLL criteria could optimize clinical outcomes by avoiding overtreatment and directing resources to those with higher disease burden. Further prospective studies are warranted to confirm these findings and guide incorporation into international practice.

Funding

This work was supported by the Brazilian Registry of CLL and the Brazilian Association of Hematology and Hemotherapy (ABHH) in collaboration with the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).

References

de Morais Marques F, Pfister V, Parra F, Perobelli L, Buccheri V, Yamamoto M, et al. Favorable outcomes of restrictive treatment indications in chronic lymphocytic leukemia: a retrospective analysis of Brazilian Registry of CLL. Lancet Reg Health Am. 2025 Sep 24;51:101234. doi:10.1016/j.lana.2025.101234. PMID: 41050339; PMCID: PMC12495331.